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Adaptive Huffman Coding

Traditional Huffman Coding uses a static dictionary, which means each item in the file is encoded the same way. Typical implementations send the encoding table to the decoder as part of the encoded file.
Adaptive Huffman coding modifies the table as characters are encoded, which allows the encoder to adapt to changing conditions in the input data. Adaptive decoders don’t need a copy of the table when decoding, they start with a fixed decoding table and update the table as characters are read in.

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Papers/Documentation

Design and Analysis of Dynamic Huffman Codes Rate
J. S. Vitter. “Design and Analysis of Dynamic Huffman Codes,” Journal of the ACM, 34(4), October 1987, 825-845. Full paper in PDF and Postscript format.
A Memory-Efficient Huffman Adaptive Coding Algorithm for Very Large Sets of Symbols Rate This paper describes an adaptive Huffman scheme that is designed to work with large numbers of symbols – at least that’s what the abstract says. The web page indicates that there are executables in the archive, but all I see is a Word document.
Source Code

David’s Compression Page This page has a some Huffman compression code that has been adapted to implement a unique property that author refers to as one to one compression. In a nutshell, this property means that for any file X, F( F'( X ) ) == X. (F is either the compressor or decompressor, and F’ is its opposite number.)This is definitely not the case for most conventional compression algorithms.
Charles Bloom’s Adaptive Huffman Program Rate
This is a fairly small C program that was developed on the Amiga.
Note: I’m not sure why, but this page gets a very high number of ratings, nearly all very favorable, although Kate W. did claim: Parts missing from the source code, can’t build.
ALGORITHM 673 Dynamic Huffman Coding Rate
Jeff Vitter’s Pascal implementation of his Adaptive Huffman algorithm. Naturally, this ACM submission is documented in a somewhat academic fashion.
Adaptive Huffman Encoding Rate
A library to perform adpative Huffman coding as described by Knuth in J. Alg. Nice clean looking C source code.
This link continues to be one of the most popular links at DataCompression.info. Reader Karl M. had this comment about the page: The program has a few problems converting from one-based to zero-based arrays. The code for incorporating the last symbol grabs an extra input bit, but since this is usually the EOT symbol, the bug doesn’t always cause problems..
Statistical Coders Rate
A group of statistical coders from Charles Bloom. This includes several different entropy encoders, including Huffman, Adaptive Huffman, CACM Arithmetic coding, and a Skew Coder.
Adaptive Huffman Compression Rate C# implementation of adaptive Huffman coding. Implements both the FGK and Vitter algorithm variations. Compression provided through two public classes, AdaptiveHuffmanProvider and AdaptiveHuffmanStream. Good compression ratios for text-based data
David’ Scott’s Bijectified Vitter Adaptive Compression Rate David Scott presents an implementation of Vitter’s dynamic Huffman compressor, adapted so that it is bijective. Don’t know what bijective means? Check out David’s home page for more details.
Tutorials, Reference, Presentations

David’s Compression Page This page has a some Huffman compression code that has been adapted to implement a unique property that author refers to as one to one compression. In a nutshell, this property means that for any file X, F( F'( X ) ) == X. (F is either the compressor or decompressor, and F’ is its opposite number.)This is definitely not the case for most conventional compression algorithms.
Adaptive Huffman Coding Rate
A nice description of Adaptive Huffman Coding, as seen through a couple of different algorithms. I believe this is part of a survey paper by Debra A. Lelewer and Daniel S. Hirschberg.
Video and Audio Compression Rate
Class notes on lossless compression algorithms. Quick info on Huffman, Adaptive Huffman, and LZW.
The Lossless Compression (Squeeze) Page Rate
This page is designed made to teach people about Lossless compression algorithms through the use of text graphics and Java Applets! Dominik Szopa has created pages that demonstrate Huffman, Adaptive Huffman, and LZW compression.
DCL reader SF has this to say: While the site itself is rather quick, it’s disorganized…the Java applets really don’t show what’s going on at all. They show only the external effects…This site has definate potential, and I do recommend people see it. However, it’s also got a ways to go yet. .
David’ Scott’s Bijectified Vitter Adaptive Compression Rate David Scott presents an implementation of Vitter’s dynamic Huffman compressor, adapted so that it is bijective. Don’t know what bijective means? Check out David’s home page for more details.
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Archiving

An archive is a file that contains (possibly) multiple compressed files. It will also usually contain additional information about the file, such as file length, date, permissions, compression type, and so on. One of the most popular formats for file archives is the Zip format, originally developed by PKWare, and now supported by many other free and commercial programs.
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Commercial Libraries

Xceed Zip for .NET A true native Microsoft.NET Zip file-handling and streaming compression class library. Its true object-oriented design makes manipulating zip files as easy as manipulating regular files and folders. Written entirely in managed C#, it includes a variety of VB.NET and C# samples and takes full advantage of the .NET runtime’s capabilities.
DC Micro Home page for DC Micro, home of Crusher!, the data compression toolkit
Xceed Zip Compression Library A feature-rich COM/ActiveX and DLL component for adding Zip and Unzip to your Windows apps with minimum effort. Includes full documentation with many samples and examples for VB, VC++, Delphi and C++Builder to get you started quickly. Supports the latest zip file format updates including Deflate64 compression and Zip64 headers. Also includes BZip2 compression which is excellent for compressing XML data.
Abbrevia 3 by TurboPower Rate
A Delphi VCL that adds support for Zip and CAB files to your Delphi programs. From TurboPower.
ZipTV Rate
The ZipTV compression suite is a set of components to be used with Borland’s Delphi and C++ Builder products. Manage archives, SFXs, etc, with support for at least 15 archive formats.
Reader Joseph K. says Amazing collection of compression tools!.
DynaZIP-GT Rate
A set of Win32 libraries, DLLs, and controls that let you manipulate tar and gz format archives under Win32.
A DCL user had this to say: Worked very quickly, very reliable, absolutely worth the money, I had it running correctly in 5 minutes, mabye less. There was also more than enough sample code to work with. It’s the best G-zip compression library I have found anywhere..
Microsoft Cabinet Software Development Kit Rate
The Cabinet Software Development Kit provides developers with the components needed to utilize Microsoft’s cabinet file technology within other applications, or to build cabinet file management tools. Microsoft is committed to making cabinet files an open technology.
DCL User says: Easy implementation and works with memory mapped file too.
Compression Plus 5.0 Rate EllTech makes a compression library that supports zip files, plus a bunch of other formats, including ARC, ARJ, tarballs, etc.
Update! EllTech’s products were acquired by BeCubed Software. Compression Plus 5.0 appears to still be available.
Delphi Skunkworks – Data Compression Rate A page full of links to data compression resources for Delphi Programmers. Mostly libraries.
Commercial Programs

Xtractor Plus Home of Xtractor Plus, handy multiple archive extraction utility for Zip, Rar, Ace, and Arj type archives.
Absolute Packager from Xceed Software Inc Easily create sharp-looking, feature-rich Self-Extracting (.EXE) Zip files with this handy desktop application. Lets you quickly select a group of files to zip up and put into a .EXE file. Even supports being able to split the .EXEs across multiple floppy disks.
Squeez – The Ultimate Compression Utility Rate
Squeez is a fast file compression application, supporting many different archive formats. It reads and writes files in the formats ACE, ARJ, BZIP, CAB, GZIP, LZH, RAR, SQX, TAR, UUE and ZIP without any additional software. Unlike many other archivers, Squeez can read and write ZIP files (so called Zip64 archives) that have no limits regarding their maximum size or the maximum number of files within. The new SQX archive format supported by Squeez is an open archive format without any limits regarding the maximum archive size or the maximum number of files within. Special compression algorithms for executables (EXE, DLL) and multimedia files as well as a fast compressor for WAV files can usually compress content 8 to 30 percent better than ZIP or ARJ files.
FileStream, Inc Rate
FileStream makes quite a few compression-related programs, including TurboZip and TurboSFX. Release 5.,1 appears to have shipped sometime in the latter part of 2002.
WinHki Rate
WinHki is an archiving tool that understands the usual gamut of formats – compresses 9, decompresses 12, and one of this is its own proprietary HKI format.
ALZip Rate
Another archiver, this one supports ZIP, ACE, RAR, TAR, and ZOO formats. This appears to be a Korean product – the web page is bilingual.
ACB 2.00c Rate
George Buyanovsky’s ACB archiver. The proprietary compression scheme used by ACB gives consistently impressive compression ratios. Those ratios come at the expense of much RAM and CPU time.
PicoZip Rate
PicoZip is an award winning file compression utility that runs on all 32-bit Windows platforms such as Windows 95, 98, ME, NT4, 2000 and XP. It is extremely easy to use, yet contains many advanced features that helps you create or unzip ZIP files, as well as most other popular archive formats like RAR, ACE, LHA, JAR, etc.
PicoZip 3.0 shipping as of July, 2004.
DataCompression.info user Derek P. had this to say: This is one of the best Zip Utilities out there! The Batch Testing of Archives tool is fast and accurate!!! Other Zip Utility Makers need to take notes!.
Advanced Zip Repairer Version: 1.20 Rate
Advanced Zip Repairer(AZR) is a powerful tool to repair corrupted Zip files and Self Extracting files(SFX). It can recover your data in zip archives as much as possible, so to minimize the loss in file corruption. Currently AZR can fix all sub-types of zip files and all kinds of self-extracting files, also it will provide a tiny exe stub when repairing SFX files. Moreover, it has integrated with windows shell and supported drag & drop operations, which will make you repair files easily and quickly.
Compressia Rate
Compressia is a BWT-based archive utility with particularly high compression ratios. On Calgary, Canterbury, ACT-Text and ACT-Exe it surpasses all other BWT utilities. On Canterbury corpus it also surpasses all PPM utilities. Beta version 1.0 is available on the web site as of February, 2003.
DataCompression.info reader Juan L. said It is by far the best I’ve tried.
WinAce 2.11 Rate
WinAce released a new version of their archiving program at the end of 2000, promising exciting new features, such as support for Gzipped files, proprietary EXE, sound, and picture algorithms, and the usual list of extras.
DCL user comment: I have never seen such a lovely archiving program. The best I have used so far. Winzip can not touch this one! .
ZipWave Rate
A shareware visual archiving program that advertises that it supports 15 popular archive formats. Note the link to the French version of the program and web page.
Self-Extracting Archive Utility Rate
This program from Gammadyne is used to create a professional quality installation program out of an archive file.
Version 11.3 was shipping as of June, 2004.
UUNet FTP Site Rate
This ftp site has copies of Zoo, ARC, gzip, and zip, in some cases for multiple platforms.
BraZip 4.0 Rate
Another archiver that supports the zip format? Yep, that’s what it is.Of course, BraZip does support TAR, RAR, GZ, LHA, and a host of other formats. Cruise around the web site a bit and you’ll find the same information in Portuguese.
FEI STU Bratislava,Slovakia,Europe Rate
A very complete archive of compression programs, freeware, shareware, source, archviers, compressors, etc. They have it all. At last count this site has at least 1000 compression downloads
CODEC v3.10 Rate
CODEC is a software package that focuses on the non-destructive compression/decompression and the encryption/deciphering of one or more files in the same work session.
AIN Archiver v 2.3 Rate
Full-featured archiver AIN, the extracting utility AINEXT and the EXE-files compressor AINEXE. Compression/extraction methods used in the AIN archiver excels noticeably those used in any well-known archivers, such as ARJ, LHA and PKZIP, in both the compression rate and the performance.
One user who rated this product for the DCL said Super Product!
SBC Archiver Rate
The submitter said: SBC is Burrows Wheeler Transform based file archiver. It’s one of the fastest BWT implementations with high compression ratio. SBC also introduces a high security options with a number of strong encryption algorithms.
SBC appears to be shareware. Comment from a DCL user: Cool archiver; the author has made great effors to make it really fast and also added a lot of heuristics to behave well on multimedia data.
RAR Home Page Rate
This seems to be the official home page for RAR and WinRAR. RAR is a high performace archiver that is loved by many.
WinRAR 3.30 is out as of January, 2004.
ZipGenie Rate
ZipGenie is yet another archiver that supports a scad of formats, including zip, cab, arj, lha, lza, arc, gz, tar, zoo, gzip, rar, tgz, ace, jar, pak, and z. The author says that the download is multilingual, with help in German, English, Spanish, and French.
LIMIT version 1.2 — Data Compression/rchive utility Rate
LIMIT is a fast and compact data compressor/archiver. The compression and decompression routines have been written entirely in 80286 assembly, so it runs faster than many other archivers. LIMIT also compresses better than other archivers; it uses a compression method based on 32K sliding window dictionary plus huffman encoding, similar to LHA/PKZIP/ARJ, but with some improvments.
RAR 2.06 Rate
The RAR Archivever – text UI.
An enthusiastic DCL user had this to say about RAR: The king of archivers, period. Nothing comes close – no laughable zippers, the slow Jar, or the useless program that tries to be a competition for RAR (winace). This is the best! I’ve used RAR since its DOS beginnings, for years, and it only gets better and better!.
Streamline Archival Utility Ver 1.00 Rate
SAR is a simple archival utility that uses the Huffman algorithms. It has been designed to utilize a single executable for all functionality and has proven to be more effective than most archival utilities on the market today. Although SAR does not have a lot of the commands other utilities have, it more than makes up for it in compression and ease of use. Future releases of SAR will continually include more functionality.
PowerArchiver Rate
Yet another Windows archiving program. PowerArchiver comes with a nice long list of supported formats: ZIP, CAB, LHA (LZH), TAR, TAR.GZ, TAR.BZ2, BH, RAR, ARJ, ARC, ACE, ZOO, GZ, BZIP2, XXE, and UUE. Plus a built-in viewer for JPG, GIF, and a few other formats.
Release 9.0 of PowerArchiver shipped July, 2004.
CuteZIP 2.0 Rate
Those cute people at globalscape now have a cute zip program. It’s interesting because it not only handles Zip files, but also CAB files.
Version 2.1 shipped in April, 2003, andding strong encryption and command line functionality.
JRCHIVE 1.10 Rate
JRchive is a program for compressing and storing files in an archive. It has a “concatenated archive” option that puts the files in the archive first, then compresses it for better compression ratios.
Advanced CAB Repair Rate
This tool is touted as being able to repair corrupt CAB files. It scans the file and recovers as much data as possible.
Version 1.1 is shipping as of November, 2003.
Reader Antonio P. says: Relatively useful but very expensive for infrequent use.
Disintegrator Rate
DST – shareware archiver
Packing program BSA 2.00 Rate
Archiving program that advertises support for DOS, Windows, NT, OS/2, QNX, and UNIX. This distribution has no docs, but the ACT page indicates that this is shareware, so until further notice I’ll label it as such.
ShipInBottle Archiver Rate
This is a Russian language web site, so I’ll have to apologize in advance for any mistakes. As far as I can tell, this is a PPM-based archiver. I can’t tell if it’s free or not, so I’m listing it as both!
ARX (R) archiving utility v 1.0 Rate
Another shareware archiving utility.
ARC – File Archive Utility V 6.02 Rate ARC is used to create and maintain file archives. An archive is a group of files collected together into one file in such a way that the individual files may be recovered intact. ARC automatically compresses the files being archived so that the resulting archive takes up a minimum amount of space.
Squeez Rate I believe this is the US sales home for the product Squeez, which makes its home in Germany.
Stuba mirror site Rate A mirror site for the big compression software site. See 0index.txt for a list of what’s here, an unbelievably large treasure trove.
MegaSafe Rate MegaSafe is advertised as being “one finger archive control of your critical data.” I’m not sure what that means, and there is not much more description than that on the web site.
CRUSH v1.8 Rate Fed up with limited compression performance of Stacker, PKZIP, UC2, ZOO, ARJ and LHA? CRUSH will usually give 5%-50% improved compression over any other DOS compression tool, and yet allows the user to continue using the archiver already in use. CRUSH is fast and the ideal choice for users keen to save disk space. I can’t help but note that the last update of CRUSH was in 1995!
Archive & Restore Rate With Archive & Restore, you can save, stow away and restore files easily. Stowing away files will recover space on your hard disk, increase clarity and reduce administration efforts. Saving versions of your files lets you return to a previous state, for example, while developing a project.
PAK The File Compression Utility Version 2.51 Rate PAK is a utility to create and maintain file archives in compressed form. There are several advantages to compressing files. On a hard disk, most files are accessed infrequently. Reducing the size of these files allows more of them to remain on the hard disk, where they are more accessible than on a floppy in a file cabinet, and frees disk space for other use.
Aladdin Systems, Inc. Rate Aladdin makes quite a few different software products, but the one we are concerned with is Stuffit, probably the best known archiver for the Macintosh platform.
DeepFreezer for Windows95/NT Rate The documentation for this program is in an unknown language. It appears to be an archiver that includes a developers kit.
Hamarsoft Rate I don’t know if Hamarsoft is still in business, but you can still get a copy of HAP here. Harald Feldmann was Hamarsoft.
Zipey Pro Rate Another archiver that supports ACE, ARJ, RAR, ZIP and perhaps more.
Version 3.0 is shipping in March, 2004.
Garbo repository for PC archiving programs Rate This FTP site has copies of a wide variety of archiving programs. Includes current programs such as PKZip, ARJ, and RAR, as well as historically relevant programs such as PAK and ARC. Look at 00index.txt for a directory of what’s on hand.
CrossePac Rate A data compression utility. The internal documentation states that this program can create archives using 7 bit ASCII only for maximum portability.
Planet Zip Suite Rate Another Win32 archiving program, supporting the Zip format and scads of others, as well as providing SFX, encryption, a file splitter, and best of all, a free world clock!
AckerPack – Smarter Folder Compressor Rate This commercial Win32 program is designed to take a folder and turn it into self-extracting archives in a proprietary format. Commercial, no free trial, money back guarantee.
CiderPress Rate CiderPress is a Win32 programmer that is designed to support Apple II archiving formats. Full support for ShrinkIt (NuFX) archives, plus a bunch of features that provide glue functoins for dealing with AppleII stuff on modern Windows machines.
ACT – Mac Archiver Index Rate Jeff Gilchrist maintains the well known Archive Comparison Test site, which pits all the compressors of the world against one another. This page on that site has links to the all those archivers. Lots of links.
ZipZag Rate Yet another Win32 archiver. Distinguishing features are: support for over 125 archive types, benchmarks that show it beating 7-Zip, WinRar, and WinAce for compression ratios.
PowerZip Rate An archiver that manages the usual gamut of archive types. Wizards and stuff.
Release 7.02 was shipping in May of 2004.
ARJ Software Downloads Rate This page has the official releases of ARJ, UNARJ, JAR, and so on. This includes the free source to UNARJ and the ARJ32 command line archiver.
ARJ32 version 3.11 was shipping as of 12/2003.
ARJ version 2.82 was shipping as of 12/2003.
xPress – Cross Platform File Compression Rate These guys appear to be selling a conventional file compressor that works on quite a few different desktops and mainframes. The product description on the web page manages to obscure the facts with a lot of marketing-ese, so I’m a bit fuzzy on the details.
MKS Unix Utilities Rate MKS makes UNIX utilities available on other platforms. Naturally, this includes pack, unpack, mkszip, and so on.
Ultimate ZIP Cracker Rate A program designed to crack lost passwords for zip and arj files.
WinArj Rate A version of Arj written specifically for 32 bit Windows. From Robert Jung, the author of the ARJ archiver.
TurboZip Express Rate TurboZIP Express is tightly integrated with Windows Explorer so you can ZIP, UnZIP, CAB, UnCAB, plus E-mail files, all in one quick action. You can compress files to units of any size and output to HD or FD. It lets you internally view, print or even edit files within Zip..
TurboZip Rate TurboZIP is an Archive, E-Mail Manager and Auto Backup tool. It opens major archive and E-mail formats. It offers the unique capabilities to internally view, print, copy, launch, and virus scan files within ZIP and E-mails without unzipping; unique ZIP Set and Multi-threading operation for simultaneous zipping, unzipping, auto backups..
TurboZip 5.1 appears to have been released sometime around January, 2003. Unfortunately, the FileStream web site doesn’t provide any sort of release history for this product, so it’s impossible to determine exactly when the release shipped and what features were added in 5.1.
ArchivePro 2000 Rate ArchivePro isn’t a zip program, it’s a database for all the files you’ve stored. In the process it often compresses files for you, which is how it ended up in my database.
Aladdin Dropstuff Rate Another product from Aladdin, makers of the world-famouse Stuffit program for the Mac. DropStuff comes in versions for the Mac and Windows, and will store archives in either Zip or Sit formats.
CAB Station Rate This is the home page of CAB station, and inexpensive program that manipulates Microsoft CAB files.
DropZip by Aladdin Systems Rate A commercial program that supports both the Stuffit and Zip formats. DropZip is available for both Mac and Windows platforms.
Batch Zip Toolkit Rate Despite the name, this is simply an archiving program that supports the usual gamut of compression formats, including Zip, RAR, ACE, etc.
Version 3.00 seems to be shipping in December, 2002.
Xipped Rate Advertised as The world’s most versatile and powerful archive utility! Available as shareware or free w/ads. Supports various formats, does conversions, works with the Windows shell.
ACDZip Rate ACDZip is a zipping and unzipping program that gives you the power to compress image, audio, video and document files. It includes fast image previews and is ideal for opening zip files, backing up files, saving hard disk space, preparing files for distribution and protecting them with encryption and passwords.
ArjFolder Rate ArjFolder is a utility that makes it easy to read or write ARJ and ZIP files, and to read a slew of other file types. Sit can be viewed in French or English.
ACT – PC Archiver Index Rate Jeff Gilchrist maintains the well known Archive Comparison Test site, which pits all the compressors of the world against one another. This page on that site has links to the all those archivers. Lots of links.
Compact Pro Rate Compact Pro is a shareware file compression and archival utility for the Mac. It compresses and stores files in “archives” which may span multiple diskettes. Compact Pro supports data encryption (US and Canadian users only) and self-extracting archives.
Pack Up & Go Rate Shareware compressor for the Mac. Web site claims it handles universally standard archives, a bit vague for my taste.
Advanced Encryption Package 2001 Rate This archiving package works with zip files, creates encrypted archives, wipes files, etc.
Zipbit Rate Zipbit is yet another inexpensive Win32 archiver with support for a wide range of archive types. Creates SFX files, integrates with Windows Explorer, and has localized versions for English, German, and Russian.
Version 1.05 is shipping as of April, 2003.
ArchiveXP 2003 Rate An archiver that supports 31 formats. ArchiveXP uses the 7-Zip compression format to handily beat Zip-based compressors when it comes to archive size.
SP83 of ArchiveXP 2003 was released in January of 2003.
ArchiveXpert Rate ArchiveExpert supports the standard Zip format, as well as CAB, LHA, LZH, plus extraction support for ARJ, ARC, PAK, RAR, as well as other formats. The 2.02 release shipped in August of 2002.
Stuffit Deluxe Rate Stuffit is the archiver of choice for those on the Apple platforms. Stuffit has been running on MacOS and OS/X for years, and over time added support for Windows, Linux, and Solaris. Stuffit comes in standard and deluxe versions, with a trial download available for the standard edition.
Version 8.0.2 shipped in December, 2003
MacRAR Rate MacRAR is the only RAR tool for Macintosh. Based upon Eugene Roshal’s sources and including a Mac interface, the package is delivered as shareware.
Rarissimo Rate Rarissimo is a file utility to automatically compress and/or uncompress files, companion for the award winning compression program WinRAR. Distinguishable from other compression solutions by its ability to fully preserve NTFS alternate streams. This feature provides automatic compression/uncompression for Macintosh files stored on NT volumes preserving their filenames and peculiar structures – it means for example that you can use Rarissimo to send and receive Macintosh files using any standard FTP process (and not only Mac-based programs).
DataCompression.info user Marie M. said: This utility is very specialized so not easy to find. It is a great help to transfer Mac files without a special Mac ftp utility.
Official RAR/WinRAR Registration and Support Site Rate I guess this is where you go to register or get support for your copy of RAR or WinRAR.
Companies/Organizations

DC Micro Home page for DC Micro, home of Crusher!, the data compression toolkit
Xceed Software, Inc. Makers of high-quality, commercial-grade data compression, encryption and internet components for Windows developers.
AIPNL data compression pages Rate
Information on: UC2 ARC ARJ LZH RAR ZIP UCRYPT JPEG MPEG etc. I think AIPNL makes UltraCompressor.
Greenleaf Software Rate Greenleaf sells ArchiveLib, an archiving library that supports both Zip and a proprietary format
Aladdin Systems, Inc. Rate Aladdin makes quite a few different software products, but the one we are concerned with is Stuffit, probably the best known archiver for the Macintosh platform.
Official RAR/WinRAR Registration and Support Site Rate I guess this is where you go to register or get support for your copy of RAR or WinRAR.
Finnish

SBC Archiver Rate
The submitter said: SBC is Burrows Wheeler Transform based file archiver. It’s one of the fastest BWT implementations with high compression ratio. SBC also introduces a high security options with a number of strong encryption algorithms.
SBC appears to be shareware. Comment from a DCL user: Cool archiver; the author has made great effors to make it really fast and also added a lot of heuristics to behave well on multimedia data.
French

ZipWave Rate
A shareware visual archiving program that advertises that it supports 15 popular archive formats. Note the link to the French version of the program and web page.
ZipGenie Rate
ZipGenie is yet another archiver that supports a scad of formats, including zip, cab, arj, lha, lza, arc, gz, tar, zoo, gzip, rar, tgz, ace, jar, pak, and z. The author says that the download is multilingual, with help in German, English, Spanish, and French.
ArjFolder Rate ArjFolder is a utility that makes it easy to read or write ARJ and ZIP files, and to read a slew of other file types. Sit can be viewed in French or English.
Compact Pro Rate Compact Pro is a shareware file compression and archival utility for the Mac. It compresses and stores files in “archives” which may span multiple diskettes. Compact Pro supports data encryption (US and Canadian users only) and self-extracting archives.
Rarissimo Rate Rarissimo is a file utility to automatically compress and/or uncompress files, companion for the award winning compression program WinRAR. Distinguishable from other compression solutions by its ability to fully preserve NTFS alternate streams. This feature provides automatic compression/uncompression for Macintosh files stored on NT volumes preserving their filenames and peculiar structures – it means for example that you can use Rarissimo to send and receive Macintosh files using any standard FTP process (and not only Mac-based programs).
DataCompression.info user Marie M. said: This utility is very specialized so not easy to find. It is a great help to transfer Mac files without a special Mac ftp utility.
German

ZipGenie Rate
ZipGenie is yet another archiver that supports a scad of formats, including zip, cab, arj, lha, lza, arc, gz, tar, zoo, gzip, rar, tgz, ace, jar, pak, and z. The author says that the download is multilingual, with help in German, English, Spanish, and French.
AMG Version 2.3 Rate
The docs say it all: der ultimative FREEWARE-Packer. Yes, the internal documentation for this archiver is in German, but users limited to English should still be able to figure this program out.
PowerArchiver Rate
Yet another Windows archiving program. PowerArchiver comes with a nice long list of supported formats: ZIP, CAB, LHA (LZH), TAR, TAR.GZ, TAR.BZ2, BH, RAR, ARJ, ARC, ACE, ZOO, GZ, BZIP2, XXE, and UUE. Plus a built-in viewer for JPG, GIF, and a few other formats.
Release 9.0 of PowerArchiver shipped July, 2004.
Compact Pro Rate Compact Pro is a shareware file compression and archival utility for the Mac. It compresses and stores files in “archives” which may span multiple diskettes. Compact Pro supports data encryption (US and Canadian users only) and self-extracting archives.
Zipbit Rate Zipbit is yet another inexpensive Win32 archiver with support for a wide range of archive types. Creates SFX files, integrates with Windows Explorer, and has localized versions for English, German, and Russian.
Version 1.05 is shipping as of April, 2003.
Japanese Language Resources

Common Archives Library Project Rate
Home page for the Common Archivers Library project. This page is completely in Japanese, but an English version of the index is available at a single click. The goal of this project appears to be to provide standard library software that works with any and all archives. Good idea.
Compact Pro Rate Compact Pro is a shareware file compression and archival utility for the Mac. It compresses and stores files in “archives” which may span multiple diskettes. Compact Pro supports data encryption (US and Canadian users only) and self-extracting archives.
Links

Common Archives Library Project Rate
Home page for the Common Archivers Library project. This page is completely in Japanese, but an English version of the index is available at a single click. The goal of this project appears to be to provide standard library software that works with any and all archives. Good idea.
RAR 2.70 Rate
This site appears to have a massive number of links to the current versions of RAR. The entire site is written in Dutch.
Archivers to download Rate A big list of pointers to archive programs for the Amiga platform.
Yahoo UNIX Archiving Links Rate Yahoo links to UNIX archiving software sources.
Archivers.8m.com Rate This site promises to deliver links and copes of every archiver know to man, along with news, polls, and more. The usual disclaimer apologizes for not being quite there due to a recent change in management.
Amiga compression formats Rate A good resource for anyone using compression or writing compression code for the Amiga platform. Includes tutorial and background information as well as links to code.
Newsgroup Posts

What is an archiver? Rate
Answer to this question from the comp.compression FAQ.
Non-Commercial Libraries

Zzip – The New Compressor A new archiver that uses a BWT algorithm to achieve superior compression. The author has now released the source code to zzip under the GPL.
SQX Archiver! Rate
The folks at SpeedProject in Germany have created a developer’s toolkit that gives you full access to the SQX format archives created by their Squeez and SpeedCommander utilities. The toolkit and DLLs are completely free.
Common Archives Library Project Rate
Home page for the Common Archivers Library project. This page is completely in Japanese, but an English version of the index is available at a single click. The goal of this project appears to be to provide standard library software that works with any and all archives. Good idea.
aPlib Compression Library Rate
32bit pmode compression library based on the algorithm used in aPACK. Both the library and some samples are included on this page.
TZipTV Delphi 32-bit component Rate
TZipTV returns to the programmer internal file information of files compacted within a compressed archive. Archives supported include ZIP, ARC, LZH, LHA, HA, RAR, PAK, ARJ, ZOO. Seperate extraction components included in this package are TUnZIP, TUnARJ, TUnARC, TUnLHA, TUnZOO. Also contains TUnSFX (exe to archive).
UniquE’s RAR File Library Rate
The URARFileLib is a small library that allows you to read files from RAR archives created with RAR and WinRAR. Decompression and decryption with full RAR v2.0 compatibility is done directly in your application, thus there is no need for a DLL or any other external file. This file library is based on the free unRAR source code by Eugene Roshal, and designed for easy but powerful usage in demos and intros. This library is also useful if you want to port your demos since the URARFileLib supports multiple operating systems (Linux, SunOS, and Win32).
Update: As of June, 2002, The library is hosted at a new URL, has a new dual license, and improved samples for Win32, Linux, and UNIX.
Huffman Compression Engine Rate This program is currently capable of reading and extracting files made with LHA and other utilities that generate .lzh files, from -lh4- to -lh7-. The foundation of the algorithm for this program like ARJ is based on Haruhiko Okumura’s work on ar002, which was the foundation of LHA. Unlike Haruhiko’s work however, the dictionary size is dynamic and currently allows for dictionary sizes of up to 64KB. On larger files, compression of files is usually 0.5% to 5% tighter than PKzip, and work in progress will likely yield even better results. Files created with this utility natively create -lh7- signed archives, which on larger files results in slightly better compression than that of lha32 by Haruyasu Yoshizaki.
libcomprex – Comprex (de)compression library Rate From the site: The libcomprex library transparently handles automatic compression and decompression of files. The API is similar to C’s built-in file access functions, which provides a smooth transition to libcomprex. libcomprex can also open uncompressed files, making it a good replacement for the native file access functions.
CodeProject archiver – targets files and/or Win32 resources Rate This CodeProject article presents an archiver that moves files in and out of an archive, and will extract from resources as well. It doesn’t support the standard Zip format, and in a blinding flash of frankness, the author says The code is crap but it works and I couldn’t find it done anywhere else.
Delphi Zip Rate Delphi Zip is a set of libraries for Delphi based on the Info-zip library releases.
Delphi Skunkworks – Data Compression Rate A page full of links to data compression resources for Delphi Programmers. Mostly libraries.
NuLib Home Page Rate NuLib is a program for the Apple II which manipulates NuFx archives. The page is also the distribution site for NuLib2, and improved version of the program, and NufxLib, a programming library.
Non-Commercial Programs

Zzip – The New Compressor A new archiver that uses a BWT algorithm to achieve superior compression. The author has now released the source code to zzip under the GPL.
IZArc Rate
IZArc is a free multi-format archiver. Supports the following formats: ACE, ARC, ARJ, BH, BZ2, CAB, ENC, GZ, HA, JAR, LHA, LZH, MBF, MIM, PAK, PK3, RAR, TAR, TBZ, TGZ, UUE, XXE, Z, ZIP, ZOO. Pretty good list, wouldn’t you say?
UNSIT — StuffIt Archive File Disassembler Rate
UNSIT is a simple utility for PC users to extract files from a StuffIt file. StuffIt files usually appear with the “.SIT” extension. StuffIt is a program for Macs similar to ARC for PCs. It collects several files in a single file and also compresses the data using run length, Huffman, or LZW compression. Unfortunately, this means Mac files are frequently inaccessible to PC users as they are now “stuffed” to save transmission costs and disk space.
UltimateZip Rate
The folks at UltimateZip bill their freeware program as The Archive Program for the New Millenium, and why not? It has a full set of archive types that it supports, built in disk-spanning, skins, the works. It looks pretty good.
Release 2.7.1 shipped in September, 2002.
Winimp – The Archiver for the 21st Century Rate
WinImp has been re-released as freeware. This archiver can create Zip files, and extract from the usual list of Zip, ARJ, RAR, and so on. It includes a couple of proprietary (BWT-based?) algorithms that purport to do well on text files.
DataCompression.info user Mike notes that It includes 2 very good compression methods and only the new versions of Winrar, Winace or Rk can compete with the compression ratios of Winimp.
UUNet FTP Site Rate
This ftp site has copies of Zoo, ARC, gzip, and zip, in some cases for multiple platforms.
DC Archiver Rate
DC is a BWT based archiver by Edgar Binder. Is it free? Not sure, but no source.
Booz 2.0 — Barebones Zoo Extractor/Lister Rate
Booz 2.0 is a small, memory-efficient, public domain Zoo archive extractor/lister. It is not fancy. It does not recognize the advanced features available in current versions of Zoo, such as long filenames, directory names, comments, and multiple file generations. Extraction always uses a short MS-DOS format filename and all extracted files go into the current directory
LHA Ver 2.55E English version Rate
LHarc, a precursor to the LHA file utility, became one of the standard file compression/extraction utility in Japan despite its slowness. I am also pleased that some overseas users have taken to using this tool.
OpenUp Rate
OpenUp allows you to double-click on compressed and archived files and have them open in the Workspace without having to resort to the command-line tools gnutar and gunzip. It also supports opening many other common, and uncommon formats. Appears to be free, with source available.
WinBig Rate
A file archive utility written in VB. Compression and decompression routines are LZSS. Full source code included.
FEI STU Bratislava,Slovakia,Europe Rate
A very complete archive of compression programs, freeware, shareware, source, archviers, compressors, etc. They have it all. At last count this site has at least 1000 compression downloads
RK Home Page Rate
Another archiver, released under GPL. No source released as of yet. The author reports that RK is a strong contender for best compresson ratios among the current crop of archivers.
DCL user reports “One of the best compressors available.”
ASD – archiver version 0.1.4 Rate
A freeware archiver from Sweden. Versions available for DOS, Windows, and Linux, with Win9x long filename support. Includes source for extraction from ASD archives.
DCL user feedback: Finally i found what I was looking for, a freeware archiver for both Windows, Dos, and Linux!
Another user said: Offers What I waslooking for, very helpful.
DAR – Disk Archive Rate
A command line program for making backups of directory trees and files. This freeware is ported to Linux, Windows, and Solaris.
Version 2.0.2 shipped in December, 2003.
ZipStar Rate
ZipStar is a free archiving application for home users. It can create, modify and extract the archive formats SQX, CAB and ZIP. Besides the application itself, ZipStar also provides an extension for the Windows Explorer. With this extension it is possible to extract or create archives directly within Windows Explorer.
ZipStar may be used free of charge if you
are a student, teacher or some other kind of member of a teaching facility (public/private school or university);
use the software exclusively for private and non-profit purposes.
Zoox is an enhanced version of zoo 2.01 Rate
Zoox is an enhanced version of zoo 2.01 from Andre van Dalen. It will allow you to archive a set of files into a series of zoo archives, each limited to a size that you specify. Thus a large number of files on a hard disk can be stored in compressed form on a series of floppy disks.
AMG Version 2.3 Rate
The docs say it all: der ultimative FREEWARE-Packer. Yes, the internal documentation for this archiver is in German, but users limited to English should still be able to figure this program out.
ARJZ 0.15 alpha Rate
This appears to be a freeware archiver. I’m unable to give more information; all the documentation is in an unkown language. Any reader who is able to translate is invited to improve on this description.
BVI 1.7 – Single file compressor/decompressor Rate
This is freeware with no source. The docs claim a fast algorithm with arithmetic coding.
BOA Constrictor Archiver v0.58b Rate
A freeware archiver.
ARQ Crusher! Archive Utility v3.2 Rate
This is an archiver that appears to have been designed with the DC Micro Development Crusher! Library. No documentation in the package, I’m assuming this is freeware.
ShipInBottle Archiver Rate
This is a Russian language web site, so I’ll have to apologize in advance for any mistakes. As far as I can tell, this is a PPM-based archiver. I can’t tell if it’s free or not, so I’m listing it as both!
Package: makeself Rate makeself is a small shell script that generates a self-extractable archive from a directory. The resulting file appears as a shell script (many of those have a .run suffix), and can be launched as is. The archive will then uncompress itself to a temporary directory and an optional arbitrary command will be executed (for example an installation script). This is pretty similar to archives generated with WinZip Self-Extractor in the Windows world. Makeself archives also include checksums for integrity self-validation (CRC and/or MD5 checksums).
Unziplify Rate This is a freeware program that unzips all the zip files it finds in a given Win32 directory. Thank Tabdown Enterprises for the good work.
Stuba mirror site Rate A mirror site for the big compression software site. See 0index.txt for a list of what’s here, an unbelievably large treasure trove.
SCRNCH Rate SCRNCH is a data compressor designed for people, such as software developers, who need to send programs or files to a large number of people cheaply. It provides a high degree of compression and the ability to customize the self-extracting compressed file. SCRNCH takes its time to produce optimal compression, but decompression is automatic and very fast.
zoo – manipulate archives of files in compressed form Rate Zoo is used to create and maintain collections of files in compressed form. It uses a Lempel-Ziv compression algorithm that gives space savings in the range of 20% to 80% depending on the type of file data. Zoo can store and selectively extract multiple generations of the same file. Data can be recovered from damaged archives by skipping the damaged portion and locating undamaged data with the help of fiz(1).
unaceX Rate An ACE file extractor for OS X. Freeware.
Version 1.1 is shipping as of May, 2004.
ExtractorPC 1.00 Rate ExtractorPC is a free utility for expanding the files in archives created by Compact Pro(tm).
ARCE Version 4.0g Rate Use ARCE to extract files from an ARC archive file. ARCE is a freeware package.
Unpackit Rate Packit (Mac pit) file unpacker
Garbo repository for PC archiving programs Rate This FTP site has copies of a wide variety of archiving programs. Includes current programs such as PKZip, ARJ, and RAR, as well as historically relevant programs such as PAK and ARC. Look at 00index.txt for a directory of what’s on hand.
TinyHAP v1.02c Rate Tiny HAP is based on Harald Feldman’s HAP & PAH 3.0, and is distributed freely. The source code is not identical and should run 25% faster.
kArchiver Rate An archiver program designed to run under Linux with the KDE desktop. Looks like it supports tar, zip, bz2, and gz files. Released under the GPL.
Version 3.0.10 is shipping as of January, 2004
The Heirloom Toolchest Rate The Heirloom Toolchest includes Open Source cpio and tar implementations running on Linux, Solaris, and Open UNIX. cpio is able to read and write all known Unix cpio archive formats, including proprietary ones, and zip files, including support for the zip64 format.
The most recent update of the project was on June 30, 2004.
KDar — the KDE Disk archiver Rate KDar is the KDE Disk Archiver. It is a convenient graphical interface to Denis Corbin’s libdar archiving and backup C++ library. You can safely backup (with compression if you like), view and restore files using KDar, along with a few easy UNIX commands for mounting and burning CD-R’s, Zip and Jazz drives, DVD-R’s, floppies, or any other disk-based storage media.
Star Rate Star is a free tar program, and boasts that it is the first free tar program to support POSIX.1-2001 extended tar headers.
Archive Converter Rate This freeware program is used to convert archives from one format to another. It says it supports “any archiver,” I guess you can’t ask for more than that.
Archive Explorer Rate Archive Explorer is a pure VB program that is capable of showing the contents of different archives and some archives can be extracted. Contents can be shown are: ZIP,GZ,TGZ,TAR,ARC,ARJ,RAR,CAB,LZH,LHA. Contents can be extracted are: ZIP,GZ,TGZ,TAR.
PhpZip Rate A Php application to manage compressed archives. Handles Zip, tar, and proprietary archives.
Archive Rate This product seems to have chosen the obvious name, so that’s a good start. It appears to be an archiver for *NIX that can work with tgz, tar, bz2, zip, and jar archives. It’s Python, and it appears to be free.
Version 1.9.4 is shipping in March, 2004.
Bee Archiver Rate This is an archiver. That’s all I know – the web page is in Russian, and the Babel Fish translation didn’t give me too much additional information.
bsdtar, libarchive Rate Libarchive is a programming library that can create and read several different streaming archive formats, including most popular tar variants and the POSIX cpio format. The bsdtar program is an implementation of tar(1) that is built on top of libarchive. It started as a test harness, but is quickly moving toward becoming a candidate system tar for FreeBSD
UFUP Rate UFUP advertises itself as a “decompression utility that handles common Unix package formats such as bzip2, gzip, and tar.”
TAR.GZ File Compression for Windows Rate Tar and tar.gz files are very familiar to *NIX users, but not to everyone using Windows. To help those folks out, ezGZ has been created, which manipulates these archives in a nice GUI-friendly way. Source included.
ACT – Mac Archiver Index Rate Jeff Gilchrist maintains the well known Archive Comparison Test site, which pits all the compressors of the world against one another. This page on that site has links to the all those archivers. Lots of links.
BZip2 for Java Rate Aftex Software makes a Java version of Bzip2. This includes input and output stream classes, which can be used in other Java applications. The program has both a GUI and command line interface.
cabextract Rate cabextract is a GPLed program which extracts Microsoft Cabinet (.CAB) archives. It fully supports both the MSZIP and LZX compression formats. It can also extract multi-part archives and self-extracting archives.
Release 1.0 shipped in March, 2004
p7zip Rate p7zip is a quick port of 7za.exe (command line version of 7zip, see www.7-zip.org) for Unix. 7-Zip is a file archiver with highest compression ratio.
Version 0.81 is shipping as of July, 2004.
CabPack Rate A freeware program that you can use to create CAB files.
Aladdin Expander Rate Aladdin Systems, makers of the popular Stuffit program, have a free program called Expander that can be used to extract files from many popular archive formats, including Zip, Sit, and more.
Package: unrar (1:0.0.1-1) Rate Unrar can extract files from .rar archives. Can’t handle archives in the RAR 3.0 format.
Bzip2 mini-HOWTO Rate David Fetter wrote a Linux howto telling you how to compile, install, and use bzip2, the BWT-based freeware archiver.
GCA(G Compression Archiver) Rate GCA is a freeware portable general purpose lossless compression program. English version of this page should be here.
SFXMaker Rate A free tool to convert zip file into self-extracting executables. Integrates with PowerArchiver.
ACT – PC Archiver Index Rate Jeff Gilchrist maintains the well known Archive Comparison Test site, which pits all the compressors of the world against one another. This page on that site has links to the all those archivers. Lots of links.
Mind Expander Rate Archive expander for the Mac and Windows. Whether you’re using Mac or a PC, MindExpander will expand ZIP, SIT, SEA, HQX, and other popular compression formats. Free software.
MacBzip2 Home Page Rate A port of Julan Seward’s bzip2 program to the Mac. It’s free and full source is included if you are the adventurous type.
lesspipe Rate lesspipe.sh is an input filter for the pager less as described in its man page. The script runs under a ksh compliant shell (ksh, bash, zsh) and allows to view files with binary content, compressed files, archives and files contained in archives. A large and growing number of formats are supported both as plain and compressed files using compress, gzip, bzip2 or zip.
Bloat Rate Bloat is a Perl script which analyses an archive’s filename and extracts it using a suitable extractor.
Guntar – Uncompress Untar tool Rate From the SourceForge site:
Guntar is the lazy man’s decompression, untar, utility. Do you download a lot of source? Do you keep forgetting the tar flags to decompress zipped archives? If so Guntar is for you.
Looks as though the 0.4.2 beta release of Guntar shipped at the end of January, 2003.
BAR Rate BAR Archiver is a free, cross-platform file compression and archiving tool written in Java. It outperforms most of the popular file compression tools available as commercial utilities. Compression is based on Burrows Wheeler Transformation and modified Huffman entropy coder. The compression ratio is in par with most of the commercial grade compression utilities.
UFA Archiver version 0.04 Beta 1 Rate A freeware archiver that claims high compression ratios. The hypermart web site includes two additional experimental versions of this archiver called BIX and 777.
Unace – extract, test and view .ace archives Rate The unace utility is used for extracting, testing and viewing the contents of archives created with the ACE archiver.
ColdCompress Rate ColdCompress presents an easy to use GUI for creating .tar.gz archives on Mac OS X Server.
NuLib Home Page Rate NuLib is a program for the Apple II which manipulates NuFx archives. The page is also the distribution site for NuLib2, and improved version of the program, and NufxLib, a programming library.
dczip Rate This is a free program that the author describes as a clone of WinZip. It is written entirely in Java and supports a nice variety of archive formats, including zip, jar, gzip, and bzip2 Requires Java 1.3, 1.4 is recommended. The 1.0 release shipped in May of 2002.
PAR Rate A Win32 compression program. Free, and it appears to have very good compression.
GNU Tar Rate The venerable archiving program.
Version 1.14 shipped in May, 2004.
Papers/Documentation

PKZIP Appnote Rate
This ftp site contains the PKZIP and InfoZip appnotes in various incarnations, plus RFCs 1950, 1951, and 1952. It is referenced in the zlib docs as if it were the official location for the gzip specification. If you are attempting to understand the format of PKZIP archives you need this document Copies of RFCs 1950, 1951, and 1952 are here as will.
Portuguese

BraZip 4.0 Rate
Another archiver that supports the zip format? Yep, that’s what it is.Of course, BraZip does support TAR, RAR, GZ, LHA, and a host of other formats. Cruise around the web site a bit and you’ll find the same information in Portuguese.
PowerArchiver Rate
Yet another Windows archiving program. PowerArchiver comes with a nice long list of supported formats: ZIP, CAB, LHA (LZH), TAR, TAR.GZ, TAR.BZ2, BH, RAR, ARJ, ARC, ACE, ZOO, GZ, BZIP2, XXE, and UUE. Plus a built-in viewer for JPG, GIF, and a few other formats.
Release 9.0 of PowerArchiver shipped July, 2004.
Results

Archive Comparsion Test 2.0 ACT – by Jeff Gilchrist. ACT is the Archive Comparison Test, a long running benchmark on well known archiving programs. Lots of good updates in May of 2002.
GIMP Source Compression Test Rate
A little short on docs here, but from the title we’d have to guess that John De Bock compresses the source code for the GIMP and lists the results.
Compressors Comparison Test WIN | KOI | LAT Compressors Comparison Test Compressors Comparison Test Rate
Yoockin Vadim has a page here with ratings of 10 popular lossless compressors.
July 96 Benchmark Rate
A comparison of several popular archivers.
May97 Benchmark Rate
A comparison of JAR, RAR, and PKZIP. Lacks rigor.
DOGG’s Compression Ratings Rate A rating of roughly 20 different compressors – strictly based on size.
Practical Compressor Test Rate Unlike some other compressor comparison sites, I won’t be looking for a compressor offering for the last bit of compression. Instead I’ll try to find the most practical compressor out there.
EmilCont Ultracompression Rate This site compares compressors on the basis of compression ratios only. Speed is not an issue.
Russian

ShipInBottle Archiver Rate
This is a Russian language web site, so I’ll have to apologize in advance for any mistakes. As far as I can tell, this is a PPM-based archiver. I can’t tell if it’s free or not, so I’m listing it as both!
Zipbit Rate Zipbit is yet another inexpensive Win32 archiver with support for a wide range of archive types. Creates SFX files, integrates with Windows Explorer, and has localized versions for English, German, and Russian.
Version 1.05 is shipping as of April, 2003.
Source Code

Zzip – The New Compressor A new archiver that uses a BWT algorithm to achieve superior compression. The author has now released the source code to zzip under the GPL.
UniquE’s RAR File Library Rate
The URARFileLib is a small library that allows you to read files from RAR archives created with RAR and WinRAR. Decompression and decryption with full RAR v2.0 compatibility is done directly in your application, thus there is no need for a DLL or any other external file. This file library is based on the free unRAR source code by Eugene Roshal, and designed for easy but powerful usage in demos and intros. This library is also useful if you want to port your demos since the URARFileLib supports multiple operating systems (Linux, SunOS, and Win32).
Update: As of June, 2002, The library is hosted at a new URL, has a new dual license, and improved samples for Win32, Linux, and UNIX.
OpenUp Rate
OpenUp allows you to double-click on compressed and archived files and have them open in the Workspace without having to resort to the command-line tools gnutar and gunzip. It also supports opening many other common, and uncommon formats. Appears to be free, with source available.
WinBig Rate
A file archive utility written in VB. Compression and decompression routines are LZSS. Full source code included.
ASD – archiver version 0.1.4 Rate
A freeware archiver from Sweden. Versions available for DOS, Windows, and Linux, with Win9x long filename support. Includes source for extraction from ASD archives.
DCL user feedback: Finally i found what I was looking for, a freeware archiver for both Windows, Dos, and Linux!
Another user said: Offers What I waslooking for, very helpful.
DeepFreezer for Windows95/NT Rate The documentation for this program is in an unknown language. It appears to be an archiver that includes a developers kit.
TinyHAP v1.02c Rate Tiny HAP is based on Harald Feldman’s HAP & PAH 3.0, and is distributed freely. The source code is not identical and should run 25% faster.
CodeProject archiver – targets files and/or Win32 resources Rate This CodeProject article presents an archiver that moves files in and out of an archive, and will extract from resources as well. It doesn’t support the standard Zip format, and in a blinding flash of frankness, the author says The code is crap but it works and I couldn’t find it done anywhere else.
Archive Explorer Rate Archive Explorer is a pure VB program that is capable of showing the contents of different archives and some archives can be extracted. Contents can be shown are: ZIP,GZ,TGZ,TAR,ARC,ARJ,RAR,CAB,LZH,LHA. Contents can be extracted are: ZIP,GZ,TGZ,TAR.
bsdtar, libarchive Rate Libarchive is a programming library that can create and read several different streaming archive formats, including most popular tar variants and the POSIX cpio format. The bsdtar program is an implementation of tar(1) that is built on top of libarchive. It started as a test harness, but is quickly moving toward becoming a candidate system tar for FreeBSD
ARJ Software Downloads Rate This page has the official releases of ARJ, UNARJ, JAR, and so on. This includes the free source to UNARJ and the ARJ32 command line archiver.
ARJ32 version 3.11 was shipping as of 12/2003.
ARJ version 2.82 was shipping as of 12/2003.
Boost CRC Library Rate The Boost project is designed to put very high-quality peer-revied libraries in the hands of you and me. CRC checking has nothing to do with compression per se, but it is frequently used when archiving to validate results.
Maxcode Archive Download Page Rate Maxcode has a selection of C/C++ code here related to archiving and compression.
Grab a CAB: CAB Compression Rate Jim Mischel’s article from Visual Developer discussing the use of Microsoft’s CABINET.DLL to work with CAB files.
Delphi Zip Rate Delphi Zip is a set of libraries for Delphi based on the Info-zip library releases.
CabView Rate A Microsoft sample that demonstrates how you can parse and extract component files from a cabinet file.
MacBzip2 Home Page Rate A port of Julan Seward’s bzip2 program to the Mac. It’s free and full source is included if you are the adventurous type.
Amiga compression formats Rate A good resource for anyone using compression or writing compression code for the Amiga platform. Includes tutorial and background information as well as links to code.
NuLib Home Page Rate NuLib is a program for the Apple II which manipulates NuFx archives. The page is also the distribution site for NuLib2, and improved version of the program, and NufxLib, a programming library.
Spanish

ZipGenie Rate
ZipGenie is yet another archiver that supports a scad of formats, including zip, cab, arj, lha, lza, arc, gz, tar, zoo, gzip, rar, tgz, ace, jar, pak, and z. The author says that the download is multilingual, with help in German, English, Spanish, and French.
Standards

CAB File Format Rate
A description of the CAB file format. This doc page includes some source.
Wotsit’s Archive Formats Rate
Wotsit’s Format, the complete programmer’s resource on the net. This site contains file format information on hundreds of different file types and all sorts of other useful programming information; algorithms, source code, specifications, etc. This page has information on scads of archive formats.
TAR File Format Rate
Wotsit’s explanation of the TAR file format.
ACE file Format Rate
An explanation of the ACE file format.
SQZ File Format Rate
Documentation on the ancient SQZ file format.
RAR File Format Rate
A description of the RAR 2.02 file format. Short description without any source code.
DWC File Format Rate
An explanation of the archaic DWC file format.
HA File Format Rate
A description of the HA file format.
ARC File Format Specification Rate
A description of the ARC file format
RAR 2.00 File Format Rate
Wotsit’s explanation of the RAR 2.00 file format
Tutorials, Reference, Presentations

Optimizing Tip on Adaptive Arithmetic Coding Rate An article that describes an optimization that can be used when doing adapative arithemetic coding.
Overview of Used IDs for crunched files Rate An attempt to catalog archive types based on the first few bytes of a file. This list was created for Amiga users, but might help on other platforms as well.
Grab a CAB: CAB Compression Rate Jim Mischel’s article from Visual Developer discussing the use of Microsoft’s CABINET.DLL to work with CAB files.
Amiga compression formats Rate A good resource for anyone using compression or writing compression code for the Amiga platform. Includes tutorial and background information as well as links to code.
Lesson Eight: Archiving Utilities Rate This is apparently part of a *NIX manual. Teaches you about our good friends tar, gzip, and bzip2.
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Arithmetic Coding

Arithmetic coding is a method of encoding data using a variable number of bits. The number of bits used to encode each symbol varies according to the probability assigned to that symbol. Low probability symbols use many bits, high probability symbols use fewer bits.
So far, this makes Arithmetic Coding sound very similar to Huffman coding. However, there is an important difference. An arithmetic encoder doesn’t have to use an integral number of bits to encode a symbol. If the optimal number of bits for a symbol is 2.4, a Huffman coder will probably use 2 bits per symbol, whereas the arithmetic encoder my use very close to 2.4. This means an arithmetic coder can usually encode a message using fewer bits.

The method by which this is accomplished is somewhat complex, and is explained in some of the links shown below

[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
German

Arithmetic Coding revealed – A guided tour from theory to praxis Rate
An updated and translated version of our German paper “Proseminar Datenkompression – Arithmetische Kodierung” from 2001. To the best of our knowledge, it is the first comprehensive paper that describes the whole way from the basic principles of AC up to a simple implementation, fully documented with C++ source code.
Proseminar Datenkompression – Arithmetische Kodierung Rate
This page gives an introduction to Arithmetic Coding and shows how to implement it using floats or integers. There is also a proof of the efficiency of the algorithms, along with visualization and Win32 binaries. This page is in English and includes links to material in both German and English.
DataCompression.info user Juergen Abel found the site quite good: Clear description, especially the explanation of the renormalisation part, full source code.
Hardware

The Qx-coder Rate
IBM’s implementation of arithmetic coding known as the Q-coder is a well-known piece of work. (Patented, unfortunately.) This paper discusses an implementation of the Q coder in hardware.
Links

Arithmetic Coding Rate The NIST page on arithmetic coding from their Dictionary of Algorithms and Data Structures. A terse definition and a couple of links.
Newsgroup Posts

I need source for arithmetic coding Rate
The relevant answer to this question from the comp.compression FAQ.
Notes on the MACM-96 Arithmetic Encoder Rate Charles Bloom talks about this encoder, along with a comment from the author of the algorithm.
RM vs. DCC95 Rate Charles Bloom applies the taste test to two different arithmetic coders.
Some notes on implementing Arithcoders Rate Parts of an email conversation between Charles Bloom and Mark Carrol.
Non-Commercial Libraries

Carryless Rangecoder Rate
Mikael Lundqvist has adapted Dmitry Subbotin’s C++ rangecoder to C. Michael says it is simple and fast.
One DataCompression.info commented that some more documentation would be helpful.
Pegasus ELS Sample Code Rate Pegasus has a patented range coder that they license at no charge. This archive contains some C code that provides a sample implementation.
Non-Commercial Programs

Compression via Arithmetic Coding in Java Rate
Bob Carpenter has created a nice Java package that implements a PPM/arithmetic coding compression system. This page includes links to the source code, javadocs, and a fair amount of tutorial material. Very complete!
David Scott’s Bijective Static Entropy Compression Rate
This compressor is designed to operate on English text – it has a static probability table configured for written English.
PAQ3N Rate
Matt Mahoney says that with recent improvements by Serge Osnach, PAQ3N does better on the Calgary Corpus than any other open source compressor.
David A. Scott’s Fully Bijective Arithmetic Coder Rate
The term bijective as used by Scott means that for any given given file X you are guarantted that A( B( X ) ) == B( A( X ) ) == X, where A and B are a pair of bijectively matched programs. In this particular case, A and B are a compressor and decompressor that use arithmetic coding. Includes C++ source.
ari_b – by Michael Schindler Rate
This ftp site contains arithmetic coding source from Michael Schindler. The library code consists of a a byte oriented arithmetic coder. The arithmetic coder is based on Alstair Moffat’s paper “Arithmetic Coding Revisited,” presented at the Data Compression Conference 95 (Snowbird, UT). The source is stored in both tar.z and zip format. The 1.101 release has a bug fix at the end of the encoder.
For new versions see http://www.compressconsult.com/rangecoder/
PAQ4 Archiver Rate The latest in the series of multi-model compressors from Matt Mahoney. This improves on PAQ3n’s remarkable Calgary corpus performance by an additional 12K, at some expense in speed. Takes a whopping 84MB at runtime!
David Scott’s bijective 2nd order English compressor Rate This is compressor has static probabilities designed for English language text, encoding ASCII text and spaces only.
Papers/Documentation

Arithmetic Coding revealed – A guided tour from theory to praxis Rate
An updated and translated version of our German paper “Proseminar Datenkompression – Arithmetische Kodierung” from 2001. To the best of our knowledge, it is the first comprehensive paper that describes the whole way from the basic principles of AC up to a simple implementation, fully documented with C++ source code.
Arithmetic Coding Revisited Rate
by Moffat, Neal, and Witten. The authors of the original CACM article on arithmetic coding take a fresh look at the topic with an additional ten years of knowledge.
The Arithmetic Coding Page Rate
Alistair Moffat has put together all the links to his source code and articles on Arithmetic Coding in one tidy place.
Range encoder Homepage Rate
The range encoder is a fast multisymbol entropy coder (similar to arithmetic coding) with GNU general public license (other licenses on request). Its compression is within 0.01% of arithmetic coding. It is based on an article dated 1979, so it is believed to be patent free. This page includes a PS format paper by G.N.N Martin describing the range encoder.
The Qx-coder Rate
IBM’s implementation of arithmetic coding known as the Q-coder is a well-known piece of work. (Patented, unfortunately.) This paper discusses an implementation of the Q coder in hardware.
Ashok C. Popat’s dissertation Rate The dissertation itself, in PS format, along with code used in the dissertation. The code implements k-ary arithmetic compression.
A Two-Stage Modelling Method for Compressing Binary Images by Arithmetic Coding Rate A paper describing a compression scheme for bitonal images. Complete text of paper in compressed postscript.
Practical Implementations of Arithmetic Coding Rate A paper by Paul Howard and Jeffrey Vitter, which includes a tutorial and presentation of a fast algorithm.
Analysis of Arithmetic Coding for Data Compression Rate A paper by Howard and Vitter, available in both PDF and PS formats. The paper provides an analysis of the effect that models and various implementations of arithmetic coding have on compression.
Software Implementing Arithmetic Coding Rate Links to code and papers by Radford Neal and pals.
An Improved Data Structure for Cumulative Probability Tables Rate A paper by Alistair Moffat describing an improvement on Peter Fenwick’s method for maintaining cumulative probability tables. The pointer on this page leads to some source implementing said table.
Arithmetic Coding Revisited: A New Floating Point Technique Rate Anand Jain discusses his new technique for arithmetic coding. An executable file is included, but no source code.
Parallel Lossless Image Compression Using Huffman and Arithmetic Coding Rate by P. G. Howard and J. S. Vitter. This paper shows how images can be encoded and decoded using parallel processing. Both Huffman and arithmetic coding are examined.
On-Line Stochastic Processes in Data Compression Rate Suzanne Bunton’s PhD thesis. A recent post to comp.compression said that Bunton had used floating point math for arithmetic coding. I haven’t verified this, but it sounds worth a look.
Arithmetic Coding for Data Compression Rate by P. G. Howard and J. S. Vitter. “Arithmetic Coding for Data Compression,” Proceedings of the IEEE, 82(6), June 1994, 857-865. This paper describes arithmetic coding, and introduces a technique that uses table lookups to make the process more efficient.
Practical Implementations of Arithmetic Coding Rate This paper by Paul Howard and Jeff Vitter goes over some of the basics of Arithmetic Coding, then outlines a coder that has increased efficiency by virtue of substituting table lookups for expensive arithmetic operations.
Patents/Licenses

US5422734: Method for arithmetically encoding half-tone image in image processing system Rate An arithmetic coding patent which appears to be currently assigned to Samsung.
People

Gordon V. Cormack Rate
Gordon is the author of DMC and many publications related to data compression. This is is home page, which has links to much of his work.
Radford Neal’s Home Page Rate Radford Neal is a professor at the University of Toronto. One of his research interests is data compression, and his name appears on a couple of seminal papers on arithmetic coding. Links to papers can be found here.
Russian

Compression and Encryption Sources Rate Links to a variety of lossless coders, includes source for Huffman, arithmetic, LZSS, and other compressors.
Source Code

Michael Dipperstein’s Airthmetic Coding Page The third in Michael’s collection of pages explaining lossless compression algorithms. A nice tutorial accompanied by ANSI C source.
Arithmetic Coding + Statistical Modeling = Data Compression An article that explains arithmetic coding, plus a sample program that implements a limited sort of PPM.
Christable C. had these kind words: I have read some other articles, but not clearly known. When reading this article, I find that Arithmetic Coding is easy to know !
Compression via Arithmetic Coding in Java Rate
Bob Carpenter has created a nice Java package that implements a PPM/arithmetic coding compression system. This page includes links to the source code, javadocs, and a fair amount of tutorial material. Very complete!
Arithmetic Coding revealed – A guided tour from theory to praxis Rate
An updated and translated version of our German paper “Proseminar Datenkompression – Arithmetische Kodierung” from 2001. To the best of our knowledge, it is the first comprehensive paper that describes the whole way from the basic principles of AC up to a simple implementation, fully documented with C++ source code.
CACM 87 Arithmetic Coder Rate
A copy of the source to the seminal article in the CACM describing a scheme to perform arithmetic coding.
David Scott’s Bijective Static Entropy Compression Rate
This compressor is designed to operate on English text – it has a static probability table configured for written English.
PAQ3N Rate
Matt Mahoney says that with recent improvements by Serge Osnach, PAQ3N does better on the Calgary Corpus than any other open source compressor.
The Arithmetic Coding Page Rate
Alistair Moffat has put together all the links to his source code and articles on Arithmetic Coding in one tidy place.
BIAC Rate
A bijective arithmetic compressor written in Java. Includes all source code, seems to be free.
Proseminar Datenkompression – Arithmetische Kodierung Rate
This page gives an introduction to Arithmetic Coding and shows how to implement it using floats or integers. There is also a proof of the efficiency of the algorithms, along with visualization and Win32 binaries. This page is in English and includes links to material in both German and English.
DataCompression.info user Juergen Abel found the site quite good: Clear description, especially the explanation of the renormalisation part, full source code.
Range encoder Homepage Rate
The range encoder is a fast multisymbol entropy coder (similar to arithmetic coding) with GNU general public license (other licenses on request). Its compression is within 0.01% of arithmetic coding. It is based on an article dated 1979, so it is believed to be patent free. This page includes a PS format paper by G.N.N Martin describing the range encoder.
JPEG arithmetic encoding and decoding portable software implementation Rate
A back-end implemenation of arithmetic coding for JPEG as defined in the standard. It is distributed as an add-on that can be used with the Independent JPEG groups library. The work of Guido Vollbeding.
DMC.C Rate
Software implementing a complete DMC codec, plus code for a couple of different arithmetic encoders, and a linear time Huffman tree builder.
This program implements Dynamic Markov Compression (DMC) as described in “Data Compression using Dynamic Markov Modelling”, by Gordon Cormack and Nigel Horspool in Computer Journal 30:6 (December 1987). The Guazzo arithmetic coder is used here.

Statistical Coders Rate
A group of statistical coders from Charles Bloom. This includes several different entropy encoders, including Huffman, Adaptive Huffman, CACM Arithmetic coding, and a Skew Coder.
David A. Scott’s Fully Bijective Arithmetic Coder Rate
The term bijective as used by Scott means that for any given given file X you are guarantted that A( B( X ) ) == B( A( X ) ) == X, where A and B are a pair of bijectively matched programs. In this particular case, A and B are a compressor and decompressor that use arithmetic coding. Includes C++ source.
Carryless Rangecoder Rate
Mikael Lundqvist has adapted Dmitry Subbotin’s C++ rangecoder to C. Michael says it is simple and fast.
One DataCompression.info commented that some more documentation would be helpful.
Effective Arithmetic Coding Rate
Sachin Garg’s article and source on arithmetic coding, includes a 64-bit implementation.
Seminal arithmetic coding source code Rate The source code to the famous Witten, Neal, and Cleary 1987 CACM article on arithmetic coding. The paper is probably not legally on line anywhere, but can be found in the book Text Compression, as well as the journal. This FTP site has three different variations on the source.
Ashok C. Popat’s dissertation Rate The dissertation itself, in PS format, along with code used in the dissertation. The code implements k-ary arithmetic compression.
Multiply-free Arithmetic Coding Implementation Rate Multiply-free Arithmetic Coding Implementation – Compression version 0.0.0
Gordon V. Cormack Feb. 1993
University of Waterloo cormack@uwaterloo.ca
This source code has some traditional freeware licensign terms embedded in the code
Software Implementing Arithmetic Coding Rate Links to code and papers by Radford Neal and pals.
Compression and Encryption Sources Rate Links to a variety of lossless coders, includes source for Huffman, arithmetic, LZSS, and other compressors.
An Improved Data Structure for Cumulative Probability Tables Rate A paper by Alistair Moffat describing an improvement on Peter Fenwick’s method for maintaining cumulative probability tables. The pointer on this page leads to some source implementing said table.
PAQ4 Archiver Rate The latest in the series of multi-model compressors from Matt Mahoney. This improves on PAQ3n’s remarkable Calgary corpus performance by an additional 12K, at some expense in speed. Takes a whopping 84MB at runtime!
Pegasus ELS Sample Code Rate Pegasus has a patented range coder that they license at no charge. This archive contains some C code that provides a sample implementation.
David Scott’s bijective 2nd order English compressor Rate This is compressor has static probabilities designed for English language text, encoding ASCII text and spaces only.
Five Cents on Arithmetic Encoding Rate Aliaksei Sanko makes a few improvements to the code in the original 1987 CACM article. His sample includes a templated producer and consumer.
Standards

Standard ECMA-159 Data Compression for Information Interchange – Binary Arithmetic Coding Algorithm Rate The ECMA has a standard defintion for Arithmetic Coding.
Tutorials, Reference, Presentations

Quasi Static model Arturo Campos describes a model for arithmetic coding which results in less compression than an adaptative one, but at much higher speeds.
Range coder Arturo Campos describes a version of arithmetic coding which renormalizes in bytes, thus achiving twice the speed of an standard implementation and 0.01% less compression.
Arithmetic Coding A concise explanation of Arithmetic Coding by Arturo Campos. The easy to read article is accompanied by snippets of pseudo code.
Michael Dipperstein’s Airthmetic Coding Page The third in Michael’s collection of pages explaining lossless compression algorithms. A nice tutorial accompanied by ANSI C source.
Arithmetic Coding + Statistical Modeling = Data Compression An article that explains arithmetic coding, plus a sample program that implements a limited sort of PPM.
Christable C. had these kind words: I have read some other articles, but not clearly known. When reading this article, I find that Arithmetic Coding is easy to know !
Compression via Arithmetic Coding in Java Rate
Bob Carpenter has created a nice Java package that implements a PPM/arithmetic coding compression system. This page includes links to the source code, javadocs, and a fair amount of tutorial material. Very complete!
ELS algorithm Rate
IMPACStar Lossless Compression highlighted in April 1997 DDJ. An arithmetic coding variant known as the ELS coder. This page contains information and a pointer to code and documentation.
Arithmetic Coding revealed – A guided tour from theory to praxis Rate
An updated and translated version of our German paper “Proseminar Datenkompression – Arithmetische Kodierung” from 2001. To the best of our knowledge, it is the first comprehensive paper that describes the whole way from the basic principles of AC up to a simple implementation, fully documented with C++ source code.
Proseminar Datenkompression – Arithmetische Kodierung Rate
This page gives an introduction to Arithmetic Coding and shows how to implement it using floats or integers. There is also a proof of the efficiency of the algorithms, along with visualization and Win32 binaries. This page is in English and includes links to material in both German and English.
DataCompression.info user Juergen Abel found the site quite good: Clear description, especially the explanation of the renormalisation part, full source code.
Lossless Compression Algorithms (Entropy Encoding) Rate
An overview of the basics, including Shannon-Fano, Huffman, Arithmetic coding, and a section on LZW for good measure.
Arithmetic coding Rate
The Data Compression Research Center has an overview of arithmetic coding on this page. This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Effective Arithmetic Coding Rate
Sachin Garg’s article and source on arithmetic coding, includes a 64-bit implementation.
Arithmetic coding Rate One slide from a bigger presentation called “Morphological shape representation using the skeleton decomposition: application to image coding.”
Arithmetic Coding Rate A very brief overview of arithmetic coding.
Wikipedia Entry: Arithmetic Coding Rate The Wikipedia entry for Arithmetic coding. Too short for anything other than a thumbnail sketch.
Arithmetic Coder Visualisation Rate The author of this code created this visualization executable for a seminar.
DCL reader Drew D. downloaded the code, executed it, and had this to say about it: The program is an executable for windows with a dll and some gif’s. The program seems to require a screen size greater than 800×600 to view the fixed size window. The program is a bit cryptic to me since I only have a basic understanding of Arithmetic encoding but it offers nice step by step encoding with some statistical information. It also allows for the modifying of input types and reading from a file..
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Copyright © 2000-2002, Mark Nelson, All Rights Reserved.
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ARJ

This page documents both JAR and ARJ, a pair of archivers from Robert Jung
[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Commercial Programs

ARJ for Linux and FreeBSD Rate
Andrew Belov, from ARJ Software Russia, has announced the release of ARJ for Linux and FreeBSD. Links on this site to the OS/2 version as well, if you’re in the market for that.
ARJ 2.75 Rate
An archived copy of ARJ 2.75.
Password recovery software Rate
Elcom makes password recovery software, which includes support for Zip and Arj files.
Jazz interface for the JAR file compressor Rate The folks at Dark Horse Industries like Robert Jung’s JAR compressor. So much so that they created a graphical front end for it. Get it here.
Companies/Organizations

ARJ Software, Inc. Rate The home page for Robert Jung and ARJ. This page has links to the ARJ FAQ, downloads of the various ARJ executables, and ordering information. It also is the home page for the newer JAR archiver. Arj is now on release 2.71.
Non-Commercial Programs

Open Source ARJ Rate
The well-respected ARJ archiver is now available as Open Source software. This portable version targets DOS, OS/2, Linux, and FreeBSD. See the project home page for binary versions of previous commercial/shareware versions. (These versions were free for personal use, but not commercial.)
ARJ 2.78/3.10 build 17 is shipping in September, 2003.
SARJ v1.21 – FreeWare by TSF SoftWare Rate
Create and expand solid archives with the well-known ARJ, able to handle fool archives as it was an ARJ archive (GUS), support of Win95’s long file names, ANSI archive comment allowed, with a fast display, ANSI.SYS *not* necessary, protection against ANSI-BOMB, optimized for a minimal use of the RAM (memory), compatibility with ARJ; – security improved for encrypted arjives, often beter than C**** (a similar product);
Source Code

Open Source ARJ Rate
The well-respected ARJ archiver is now available as Open Source software. This portable version targets DOS, OS/2, Linux, and FreeBSD. See the project home page for binary versions of previous commercial/shareware versions. (These versions were free for personal use, but not commercial.)
ARJ 2.78/3.10 build 17 is shipping in September, 2003.
Standards

ARJ File Format Description Rate
A description of the ARJ file format.
JAR File Format Rate
Wotsit’s description of the JAR file format. Robert Jung’s JAR format, not the JAR format used to distribute Java classes.
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Copyright © 2000-2002, Mark Nelson, All Rights Reserved.
Copyright © 2005 Visicron Corp. All rights reserved.
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Audio

Audio compression is a little bit different from Speech compression. Speech compression can afford to deal with a much more limited range of frequencies and types of sound. Audio compression has to deal with music, speech, and other recorded sound.
[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Books

Digital Compression for Multimedia: Principles & Standards Rate Jerry Gibson, Toby Berger, Tom Lookabaugh, Rich Baker and David Lindberg. Drawing on their experience in industry, research, and academia, this powerful author team combines their expertise to provide an accessible guide to data compression standards and techniques and their applications
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Commercial Libraries

RareWares AAC Page Rate
A nice collection of AAC software, including encoders, decoders, and miscellaneous plugins.
RealNetworks Rate
Makers of lots of audio and video compression stuff.
Epigon Media Technologies Rate
It’s a little hard for me to tell what Epigon is selling. They have a nice picture of some kind of board on their front page, but I don’t think they have any hardware for sale. They do appear to have audio codecs for MPEG-1, MPEG-2, and MPEG-4, as well as what appears to be a proprietary speech codec called eSpeech.
Note: Reader Ragu says that despite the problem siwith the web page, he is a big fan of their products. He is a satisfied customer who feels their audio codecs are the best.
Windows Media 9 Series Rate
Microsoft’s web page for all things releated to the new Windows Media Player and more. At this time you can download the beta version of the new player, get information, and sample various media.
Reader Serg N. commented: Very good quality, support for [very] low bitrates, lossless mode. It’s not open source, but it’s free!
Windows Media 9 Downloads Rate
This page has links to the big batch of downloads that developers might need to work with Windows Media 9. At this time, the list of available packages includes:
Windows Media Format 9 Series SDK
Windows Media Player 9 Series SDK
Windows Media Encoder 9 Series SDK
Microsoft Windows Media Player for Pocket PC SDK
Windows Media Format 7 SDK for Macintosh
Windows Media Services SDK
Clipstream Audio Rate
Clipstream makes a java applet that gives web browsers the ability to play streaming audio without any special plugins or apps.
Intel Integrated Performance Primitives Rate Intel has created a new library designed to deal with varous primitives used in Data Compression. Intel says: Intel® Integrated Performance Primitives (IPP) is a software library which provides a range of library functions for multimedia, audio codecs, video codecs (for example H.263, MPEG-4), image processing (JPEG), signal processing, speech compression (i.e. G.723, GSM ARM*) plus computer vision as well as math support routines for such processing capabilities.Unlike their previous libraries, this is now a commercial product which is going to cost you as much as $199. Works with Windows and Linux.
Qdesign Rate The folks at Qdesign have a new audio encoding format they’d like you to use.
compaact! Rate compaact! allows you to easily encode your audio files with the high quality coding algorithm MPEG-4 AAC (Advanced Audio Coding). compaact! is capable of multichannel encoding and comes with extensive audio preprocessing features to achieve even better encoding results.
Version 1.2 is shipping in April, 2004.
Arcsoft Mobile Media Codecs Rate Arcsoft has a line of mobile media codecs that includes support for MIDI, JPEG, PNG, GIF, and speech.
Vibrant Communicator ActiveX Library Rate This ActiveX control is used by developers of audio applications to provide low-latency streaming compressed audio.
Windows Media Player 9 Series Software Development Kit Rate The Microsoft® Windows Media® Player 9 Series Software Development Kit (SDK) provides information and tools to customize Windows Media Player and to use the Windows Media Player ActiveX® control. This documentation also provides information about using Windows Media metafiles.
Making Windows Media Player Plug-ins Work Together Rate An article on MSDN describing the plugin architecture of Windows Media Player 9.
DirectX 9.0 End-user Runtime Rate Microsoft has released DirectX 9.0, which naturally includes support for an updated list of audio and video encodings.
Windows Media 9 Final Release Rate This page has links to download all the various components of Windows Media 9, including the media player, codecs, encoders, embedded toolkits, and more.
Asao Rate The Asao libraries from Nellysoft have been designed specifically to address the need for a very small footprint, low bandwidth speech and audio compression. Asao will operate at a variety of bit rates (12/16/24/32 Kbps). This new technology can be rapidly harnessed for applications such as streaming over mobile data networks, Internet radio and embedded platforms such as toys and other consumer devices.
Windows Media 9 Series reviewed Rate This site collects information, links, and review on Windows Media 9. Includes some detailed information on the codecs that are part of the new package.
Windows Media Video 9 Video Compression Manager Rate This tool lets you package content encoded with the Series 9 codecs in traditional AVI containers. Future applications should use the ASF file container, but legacy apps may be constrained to the AVI format. This tool allows the old and the new to work together.
This tool was shipping in a Beta version as of April, 2003.
AVPhone ActiveX Controls Rate These ActiveX controls provide real-time compression and rendering of audio and video streams, supporting standard formats such as H.263, MPEG-4, G.723 and more. It appears that they are designed for IP Telephony, but they also advertise the ability to do straight-up compression to/from disk or memory. You can use a demo version for free, with limitations, but upgrading to the pro release is going to set you back a bit. Redistribution is included in the price, though.
Version 3.0 is shipping as of April, 2003.
Commercial Programs

Blaze MediaConvert Rate
This product performs a huge number of conversions among different media types. Want to convert your huge collection of MP3 files to WMA? No problem. MPEG-2 to AVI? No problem. MediaConvert even handles some unusal conversions, such as video to animated GIF. And naturally, a huge number of conversions between various image formats, including GIF, JPG, PNG, and a host of additional types.
Release 2.3 shipped in Julyy, 2003.
ezConverter Rate
ezConverter is a program that is designed to make it easy to convert your audio files between various formats. Converts between WMA, MP3, MPEG, and many more formats. ezConverter also takes input directly from your sound card, allowing you to record from analog inputs or from the output of other programs. The publisher advertises it as fast and easy. You can download a trial version from the web site, but registration is going to set you back roughly $US 25.
Version 1.1 was shipping as of March, 2003.
RealNetworks Rate
Makers of lots of audio and video compression stuff.
Clipstream 2.0 Rate
Clipstream is a product that compresses audio to either 20Kbps or 32 Kpbs, depending on the speed of the connection. A java applet on a web page is used to decode the stream and play it over the sound card of the target computer. The web site has demos of several types of sound. Update: Clipstream has java applets for both video and audio!
TwinVQ Rate
An audio compression format invented at NTT’s Cyber Space Laboratories. Get your player and compressor right here. (English avaible by following the sharp-eyed link.)
Windows Media 9 Series Rate
Microsoft’s web page for all things releated to the new Windows Media Player and more. At this time you can download the beta version of the new player, get information, and sample various media.
Reader Serg N. commented: Very good quality, support for [very] low bitrates, lossless mode. It’s not open source, but it’s free!
Sound Compression from an Imaging Company Rate
The PIC Sound Processing System (SPS) uses the ELS arithmetic Coder from Pegasus. Here are the latest raw figures for the 4 most common sound formats. 4 formats using the full dynamic range (-32768..32767 for 16-bit and 0..255 for 8-bit).
Audio Signal Processing Software Rate
Includes editing software, file formats and converters, codecs, and links. This page is at the University of Hannover, Germany. While there appears to be a wealth of software on this site, it would appear that you need special privileges to get access to ti.
The Official daxaif Home Page Rate From the site: daxaif is a no-loss audio compression program which performs live capture or converts audio files, movie sound tracks, or audio CD tracks into a compressed “.dax” file format. This format allows fast locating and selection of audio passages through the use of a clickable compression-factor map. The selections can be played or saved in uncompressed AIFF or further compressed to AIFC format using any QuickTime-supported compresser. .
Advanced MP3 Converter Rate This conversion tool will convert between several audio formats, including WAV, OGG, and MP3. Supports ID3V1 and V2, plus other goodies.
Advanced WMA Workshop Rate This product is used to convert audio files from one format to another. The programs know how to do various conversions between WMA, MP3, and Ogg Vorbis. It’s also smart enough to do CD ripping. This appears to be shareware.
Audio Conversion Wizard Rate Audio Conversion Wizard is “All to All” converter of digital audio formats with friendly Wizard-style interface, which helps you easily convert:
WMA to MP3, OGG Vorbis, WAV PCM
WMA to WMA (resampling)
MP3 to WMA 8, OGG Vorbis, WAV PCM
MP3 to MP3 (resampling)
OGG Vorbis to WMA 8, MP3, WAV PCM
OGG Vorbis to OGG Vorbis
with ID3 Tag v2 copying and creation.
WMA MP3 Recorder Rate WMA MP3 Recorder turns your computer into complete audio recording studio. You can record sound from any internal or external source into WMA/MP3 format sound file directly without use additional disk space.
Version 5.60 is shipping as of April, 2003
ACDZip Rate ACDZip is a zipping and unzipping program that gives you the power to compress image, audio, video and document files. It includes fast image previews and is ideal for opening zip files, backing up files, saving hard disk space, preparing files for distribution and protecting them with encryption and passwords.
MediaOne+ Rate A relatively standard Windows media player. Handles DVD, MP3, DivX, etc.
Building Windows Media Player and Windows Media Encoder Plug-ins Rate Just what is says, Microsoft’s tutorial on building WMA plugins.
MediaZip Rate MediaZip is a Windows program that performs lossless compression/decompression and manages archives of media files (Sound and Picture). Welcome to the MediaZip home page.
Windows Media Diagnostic Tool Rate Having trouble with your Windows Media Player? This program gathers up all your information and stores it in a compressed file that you can quickly mail to your tech support pal in Redmond.
recorder.xhead Rate This app allows you to both record and play sounds on your Mac in various formats, including MP3 and MP4. Also includes a bulk conversion utility for changing formats, and has the ability to export to iTunes.
SFZip Rate This is a Win32 program that manages SoundFont files. These files are the ones used by Creative Labs to program their Midi cards. I think.
MUSICompress Home Page Rate The home page of the MUSICompress lossless compression method.
WMA To MP3 Converte Rate WMA To MP3 Converter was written for converting WMA to or from MP3/WAV files. So, with WMA to MP3 Converter, you may convert WMA to MP3, convert WMA to WAV, convert WAV to WMA, convert MP3 to WMA.
MP3 To WAV Converter Rate MP3 To WAV Converter is designed for converting MP3 to WAV and converting WAV to MP3. It converts batches of MP3 to WAV or WAV to MP3 on-the-fly. Play MP3/WAV files, edit Mp3 file’s ID3 text, and search MP3 or WAV files from a folder or the whole disk.
i-Sound WMA/MP3 Recorder Professional Rate This app from AbyssMedia is advertised as being able to turn your computer into complete audio recording studio. That means you have the ability to record from external inputs directly to MP3, OGG, WMA, or WAV format. Includes niceties such as MP3 and OGG tag editors, Voice Activated recording, skin support, and more.
Version 6.05 is shipping in November, 2003.
jetAudio Rate Another company determined to swim upstream with a commercial media player. Although in this case, jetAudio Basic is free, jetAudio Plus is the the commercial product. You’ll pay for the upgrade if you decide you need support for creating MP3 and MP3Pro files, broadcasting MP3 files, and converting files to MP3 or MP3Pro.
jetAudio has a nice looking UI with some alternative skins. Version 5.01 is shipping as of March, 2003.

Ace Media Player Rate Ace Media Player supports an impressive list of media types, including Real, MPEG, DivX, QuickTime, VCD, WMF, and of course, MP3. This is a commercial product, but you can get a 30 day eval copy.
Version 2.2 of Ace Media Player shipped in March of 2003.
Power WMA Recorder Rate Power WMA Recorder is a program that can create WMA files from any available sound source directly without using any additional disk space. In addition to supporting Microsoft’s WMA format (including the variable bit rate option), Power WMA Recorder can encode directly to MP3 format.
Version 1.34 is shipping in March, 2003.
wmplugins.com Rate This site describes itself as The ultimate resource for enhancing your Media Player 9 Series for Windows. By this they mean plugins, themes, skins, visualizations, etc.
Windows Media 9 Final Release Rate This page has links to download all the various components of Windows Media 9, including the media player, codecs, encoders, embedded toolkits, and more.
MMPlayer Rate MMPlayer is a Mobile Media Player for the Palm OS. It supports a wide variety of audio formats, including Windows Media, MP3, Ogg and WAV. Video isn’t supported in the current release, but is anticipated as part of MMPlayer 2.0.
Helix DNA Client Rate Real is making their client software available in an Open Source program. Download this software and you can develop your own MP3 player! Free of royalties if you are distributing it for free – commercial products pay a royalty.
All Converter Rate Yet another conversion program: All Converter is a powerful, all-in-one, multimedia application converting the media files among the most popular media formats.With All Converter,you can convert MP3 to WAV,MP3 to WMA ,MP3 to OGG,MP3 to VQF, WAV to MP3,WAV to WMA,WAV to OGG,WAV to VQF,WMA to MP3, WMA to OGG,WMA to VQF,OGG to MP3,OGG to WAV,OGG to WMA,OGG to VQF,VQF to MP3,VQF to WAV,VQF to WMA,VQF to OGG, normalize files,and support ID3 tag v1, v2 to file name conversion and vice versa.
AVI-GIF Rate This is a batch image converter that lets you go back and forth between AVI and GIF. I don’t know what the practical limits are on the size of animated GIF files, but I’ve seen some pretty cool short videos in the format. This looks to be the way to create them.
Release 1.09 shipped on July 15, 2002.
Media Wizard Rate Description from the web site: Media Wizard is a powerful, all-in-one multimedia application supporting playback of all popular formats, audio and video conversions (CD to WAV; CD to MP3; CD to WMA; CD to OGG, WAV to MP3; MP3 to WAV; WAV/MP3 to WMA; WMA to WAV/MP3; WAV/MP3 to OGG; OGG to WAV/MP3; WAV/MP3 to CD; AVI to MPG; MPG to AVI; etc.)
This is a Win32 program, and version 8.0 is shipping as of April, 2003.
Windows Media 9 Authoring Utilities Rate Creating Audio and Video content with Windows Media 9 is made possible by the authoring tools listed on this page. At the time this is entered, the list of tools includes:
Lossless to PCM Converter
Mono to Multichannel Wave Combiner
Video Compression Manager
Plug-in for Adobe Premiere 6.5
Windows Media 9 Capture
Windows Media® ASF Viewer 9 Series Rate Microsoft supplies this free tool as a way for developers to check their files for validity before shipping. Looks like it knows how to inspect ASF, WMA, and WMV files.
Welcome to Advanced RealMedia Repair Homepage Rate Advanced RealMedia Repair is a package that will help you repair your broken RealMedia files. Supports both video and audio files.
Companies/Organizations

Vorbis.com Rate
One of the home pages of the Ogg Vorbis project, this is a good place to start if you’re looking for downloads, documentation, or Ogg Vorbis software.
Nellymoser Rate
Nellymoser is the leading provider of proprietary speech and audio software technology and solutions in the areas of compression, modification, synchronization and conversion. Our products improve speech and audio quality and efficiency in bandwidth-constrained environments while creating more immersive, interactive environments for your applications and services.
SoftSound Rate
SoftSound deals with all aspects of processing the digital audio signal. We build audio coders to drastically reduce the data rate of high quality audio and speech coders for extremely low bandwidth situations. SoftSound produces the Shorten and ATELP audio coders.
IETF AVT Working Group Rate
This is the home page for the IETF group that reviews RTP packetization standards. Links on this page for all the drafts you can imagine for sending video and audio over RTP streams.
Philips – Business Team Sound Coding Rate
Historically, the BTSC has been involved in MPEG Audio from the very start. This site provides some background information on the various MPEG Audio standards.
This site provides some info on the background of MPEG, plus a couple of links to standards and so on.

KT-Tech Incorporated Rate KT-Tech seems to be active in various compression areas, developing their own algorithms rather than implementing standards. Their web site has demos of their latest still image and video technologies. One interesting product is software to improve the performance of other encoders, such as those used by Microsoft’s Windows Media codecs.
Update: the web site now offers online demos of sound compression as well!
RealNetworks Helix Initiative Rate RealNetworks has announced that they are going to be Open Sourcing a significant portion of their server products. Outlook from the Open Source community is guardedly optimistic.
ACM Multimedia 2002 Rate The ACM Multimedia conference for 2002 takes place December 1-6, 2002 in beautiful Juan-les-Pins on the French Riviera. Get your submissions in quick before the show fills up.
DAKX LLC Home Page Rate DAKX is claiming a new method of lossless data compression that is fast and patented. It works on audio and video data. The method is called difference-adaptive compression. DAKX supplies a bit of source code that you can experiment with, and will be happy to license the technology to you or your company.
Indeo Rate What was once Intel’s software now belongs to Ligos Technology. This is the home page for downloads, documentation, support, etc.
Scala Technology Rate From the submitter: This site presents a new audio coder design that achieves efficient compression with fine-grain bitrate scalability. Issues regarding scalability are discussed, and a new approach to measuring coding efficiency is presented. A windows command-line demonstration coder is availiable to download. At present the coder achieves subjective transparency at approximately 96 kbit/s/chan, similar to the FhG (non-scalable) MP3 coder.
Coding Technologies Rate These guys are responsible for some of the work that took the MP3 standard to its next revision: MP3Pro. They say their current focus is the development and marketing of SBR-enhanced codecs.
Courses/Seminars

ACM Multimedia 2002 Rate The ACM Multimedia conference for 2002 takes place December 1-6, 2002 in beautiful Juan-les-Pins on the French Riviera. Get your submissions in quick before the show fills up.
Multimedia Computing and Networking 2002 Rate The term “Multimedia” obviously covers a lot of different topics. Compression is one of them, and there is certainly a great deal to learn about compression and media formats at this conference.
Files

MPEG Audio Resources and Software Rate
Links to lots of info regarding the audio compression portions of the MPEG standards. This includes an overview, the MPEG Audio FAQ, pointers to resources, some free software, and test bitstreams.
Compression Codecs Rate This site has a nice collection of codecs, including DirectShow filters, MPG4, MJPEG, and other video codecs. A few audio codecs and AVI test sequences as well.
SQAM – Sound Quality Assessment Material Rate This site apparently holds a set of files that were used to evaluate MPEG audio compression algorithms.
Compression Technology in Multimedia Rate Lots of information on this site concerning compression of still pictures, moving pictures, and audio. Much of the site is devoted to comparisons of a few different algorithms. A report section draws a few conclusions about the whole thing.
French

MediaInfo Rate Supplies you with detailed info about the attributes of all sorts of media files, naturally including MP3, AVI, WAV, MPEG2, and much, much more. Looks to be Win32 only.
BonkEnc Rate BonkEnc is an audio CD ripper and an encoder for various audio formats. It can produce Ogg Vorbis, MP3 and BONK files. More formats are available through plug-ins.
German

GermaniXEncoder Rate GermaniXEncoder is a universal Transcoder for various sound formats like MP3, MP2, Real Audio, WMA, Ogg Vorbis, ALF2CD, DSP, GSM, G.721, G.723, G.726, RAW, PCM, ADPCM, uLaw, aLaw, MPC, and Monkeys Audio. In addition, the Encoder has a transformer for some transforming features, an Audio Recorder for recording from all input sources to mp3, mp2, pcm, adpcm, wma and ogg-vorbis. You can also split large MP3 files with their CUE sheets into songs.
Version 1.80.1195 RC2 was shipping as of Februaru, 2002.
BonkEnc Rate BonkEnc is an audio CD ripper and an encoder for various audio formats. It can produce Ogg Vorbis, MP3 and BONK files. More formats are available through plug-ins.
Japanese Language Resources

TwinVQ Rate
An audio compression format invented at NTT’s Cyber Space Laboratories. Get your player and compressor right here. (English avaible by following the sharp-eyed link.)
Links

StreamingMediaLand.com Portal site labels itself as a place with Resources for Engineers, Researchers, and Marketing People in the Streaming Media Field. The Knowledge Base has a good selection of links to standards, tutorials, code, etc. of interest to compression aficionados.
AudioCodingWiki Rate
A nice set of links to AudioCoding information. Since this is a Wiki site, it is highly collaborative – registered users can provide updates and modifications to the site at will. (I think.)
Lossless Compression of Audio Rate
My particular interest is in delivery of music via the Net – with compression which does not affect the sound quality at all. I am primarily interested in compression ratios, not speed of the programs. I think this is the first web site devoted to listing all known lossless audio compression algorithms and software – please email your suggestions and I will try to keep it up-to-date.
MPEG Audio Resources and Software Rate
Links to lots of info regarding the audio compression portions of the MPEG standards. This includes an overview, the MPEG Audio FAQ, pointers to resources, some free software, and test bitstreams.
A comparison of Internet audio compression formats Rate
A good comparsion chart showing the relative merits of various audio formats. Includes links to definitions and other support information for each format.
ASF vs. MP3 vs. RA-G2 vs. VQF Rate
A comparison of various lossy audio compression schemes. Panos Stokas provides his take on the whole situation, and includes tons of links to files, articles, and more food for thought. Most readers seem to like this web page, but one reader had this negative comment: This website is patently and fatally flawed to the nth degree. Nothing but misconception and conjecture with no real basis in scientific analysis. Very misleading to the uneducated in audio compression.. Another reader says Just reading “However, we have not found a single implementation that did not produce serious amounts of distortion in our testing sample. Nobody seems interested any longer.” about AAC of all things, makes it apparent that this guy has no idea what he’s talking about or what he’s doing.
Audio Signal Processing Software Rate
Includes editing software, file formats and converters, codecs, and links. This page is at the University of Hannover, Germany. While there appears to be a wealth of software on this site, it would appear that you need special privileges to get access to ti.
Compression Codecs Rate This site has a nice collection of codecs, including DirectShow filters, MPG4, MJPEG, and other video codecs. A few audio codecs and AVI test sequences as well.
The CWI Audio File Formats Guide Rate Useful links to information describing audio file formats.
ReallyRareWares Rate From the launch:
Hello, and be welcome to ReallyRareWares, a site for researchers (or nostalgic people like me) that miss the old days of multimedia encoding. Here you’ll find reviews and history of old software (encoders and decoders), deceased codecs (VQF, ePAC), oddities (AUPECg2, Astrid AAC), and so on, as well as downloads.
Rarewares Rate A nice collection of pointers and links to audio/music compression software.
VQF.COM Rate This web site is dedicated to the support of VQF, a new audio compression format.
Apple’s AAC Site Rate QuickTime 6 was an early adopter of MPEG-4 technology, and they seem to be big believers in the standard. This is in contrast to Microsoft’s Windows Media 9, which uses proprietary codecs to compete with the open standards of MPEG-4. The MPEG-4 standard uses AAC for encoding audio, and Apple has a site with a few links and information about this audio encoder. Alas, they don’t have a date when AAC will be included in the iPod!
Audio File Format FAQ Rate This FAQ provides good information about various audio file formats, which naturally includes quite a few compressed formats. It also has a few links to other relevant pages.
Newsgroup Posts

Are there algorithms and standards for audio compression? Rate
The comp.compression FAQ answers this question.
Doom9’s MPEG Forum Rate This site is mostly oriented towards capturing and storing DVD – good advice on how to use various tools, codecs, hardware, etc. Very active site.
Slashdot Takes on MP3 and Competitors Rate The folks at Slashdot are having a chat trying to decide what the best non-MP3 codec is for home music recording. Ogg Vorbis gets a lot of votes the last time I checked the thread, but WMA and MP3 have a fair number of adherents.
A discussion on Audio Coding, January 1999. Rate Charles Bloom thinks out loud about audio coding.
G. Orme on Music Compression Rate A proposal on comp.compression for a new method of music compression.
Non-Commercial Libraries

The OpenH323 Project Rate
This open source project aims to create a free H.323 stack. The project was started as a reaction to the high cost of commercial implementations of audio and video compression code implementing the various components of H.323. Roger H. adds There are now several useful applications which use the library including OpenMCU (a reliable multi person conference server) and GnomeMeeting (a GTK/Gnome GUI client for Linux/BSD Unix.
Version 1.13.13 of OpenH323 shipped in Marh, 2004.
Hawk Software HawkVoice Rate
HawkVoice is a game oriented, multiplayer voice over network API released under the GNU Library General Public License (LGPL), with support for Linux/Unix and Windows 9x/ME/NT/2000. It is designed to be a portable, open source code alternative to DirectPlay(R) Voice in DX8.
RareWares AAC Page Rate
A nice collection of AAC software, including encoders, decoders, and miscellaneous plugins.
The LPAC Homepage Rate
LPAC is a codec for lossless compression of 8, 12, 16, 20, and 24 bit audio files. It has cross-platform support for Windows, Linux and Solaris. Direct playback of LPAC files is possible with a Winamp plug-in. A satisfied user tells the DCL Compression on the material I use is superior to the FLAC encoder.
FLAC Source Code Rate
Source code to the FLAC library, command-line encoder/decoder, and player plugins. FLAC is an open-source lossless audio codec.
The Ogg Vorbis CODEC project Rate
Ogg Vorbis is a fully Open, non-proprietary, patent-and-royalty-free, general-purpose compressed audio format for mid to high quality (8kHz-48.0kHz, 16+ bit, polyphonic) audio and music at fixed and variable bitrates from 16 to 128 kbps/channel. This places Vorbis in the same competetive class as audio representations such as MPEG-4 (AAC), and similar to, but higher performance than MPEG-1/2 audio layer 3, MPEG-4 audio (TwinVQ), WMA and PAC.
DataCompression.info reader Serge enthusiastically said: Hell! The best lossy codec to date!
QuickTime Components Project Rate This site is dedicated to open source QuickTime development for popular open source audio and video codecs. We are currently working on Ogg Vorbis, an audio codec developed by Xiphophorus, and MNG, an animation video codec.
Tremor – Fixed Point Ogg Vorbis Decoder Rate The folks at Ogg Vorbis would like to see their audio format work its way into some hardware players. One good effort towards making this happen is a fixed=point implementation of the algorithm, which can then presumably be ported to machines using cheaper CPUs that lack the sophisticated FPUs of our desktop machines.
JMAC: Open Source Java Monkey’s Audio Decoder/JavaSound SPI Rate JMAC is a Java implementation of the Monkey’s Audio decoder/JavaSound SPI. Currently, Monkey’s Audio format up to 3.97 version supported. JMAC is distributed under the terms of the GNU Library General Public License.
Version 1.65 of JMAC is shipping as of July, 2004.
Patent-Clear and Headache-Free Sound Format Rate Charlie Cho reviews Ogg Vorbis for Web Techniques Magazine, February of 2002.
Dali Rate Dali is a project at Cornell that aims to create a programming environment dedicated to the manipulation of video, audio, and image data. Naturally, this includes multiple codecs for various data types.
VorbisSPI Rate VorbisSPI is a Java Service Provider Interface that adds OGG Vorbis audio format support to Java platform. It supports icecast streaming. It is based on JOrbis Java libraries.
Helix DNA Producer SDK Project Home Page Rate The Helix DNA Producer is a project that Real Networks has dropped into the open source space. Producer is a platform for creating streaming content and downloadable media files.
Maaate: The Australian audio analysis toolkit Rate Maaate consists of a set of libraries that let you analyze the audio streams encoded in MPEG files. Besides simply parsing the audio out of MPEG files, it also does some sort of energy detection, silence analysis and more. But reading between the lines I think this library’s strength is supposed to be a nice architecture that lets you easily add the modules you need for your work.
Digital Audio Access Protocol, Rate Apple’s iTunes 4.0 player is able to play music across a local network or the Internet, using a proprietary protocol. This protocol not only tells machines how to stream audio content, it provides access to playlists and track information as well. The folks at the Digital Audio Access Protocol project are determined to reverse engineer that protocol so they can use the iTunes protocol on other operating systems or platforms.
Read tags of .ogg files Rate This is a simple class that reads default tags (the ones suggested by xiph.org) and the common “COMMENT” tag used by WinAmp and other players and tag editors.
Java FLAC Codec Rate FLAC is a port of the Free Lossless Audio Codec (FLAC) library to Java. This library allows java developers to experiment and write programs that use the FLAC algorithms.
Version 0.5 is shipping as of June, 2004.
OptimFROG SDK Rate Florin Ghido has packaged his lossless compressor into a nice SDK – take advantage of his great audio compression in products of your own.
Foobar2000 Rate Foobar2000 is a relatively new audio player for Windows PCs. It seems to be attracting a little bit of interest among the literati, perhaps because it is mostly open sourced. It has a nice list of features, including tremendous list of codec support, as well as some unusual ones, such as the ability to play files in Zip archives.
AC3Filter Rate A DirectShow filter which will allow you to play AVI files containing AC3 encoded audio. A nice stream of releases with steady improvement.
Version 0.66b is shipping as of March, 2003.
FLAC – Free Lossless Audio Coder Rate FLAC is an open-source project which specifies a lossless compressed audio format and provides an encoder, decoder, and several player plugins. Aside from yielding better compression than Shorten, the format supports sample-accurate seeking and many other features useful for streaming and archival.
Reader Colin B. says: Incredible lossless audio compression, depending on the source, of course. I have seen high-quality speech recordings compressed to 10% of the original size, losslessly..
FLAC 1.1.0 released in January, 2003. A good roster of new features for this coder, including updates for libraries and plugins.
MediaPipe Rate MediaPipe is a flexible framework to manipulate media on MacOS X. It allows you to build decoding, filtering, encoding and even streaming pipelines that correspond exactly to your needs. Additionally, if a format is not supported, or a transformation missing, it features an SDK that allows you to quickly implement the pipe you want.
AVI File Support Library Rate This open source project gives you the ability to read and write AVI files under Linux. The really interesting part about all that is that this is done using the Win32 DLLs from Microsoft to do the compression and decompression. Clever!
The avifile component is shipping version 0.7.37 as of May, 2003.
OGG-S Rate OGG-S is an open source project that aims to create a Digital Rights interface for all media files, but particularly for Ogg Vorbis.
This project is shippnig Beta 1 in March, 2003.
Non-Commercial Programs

Kexis Rate
An open source lossless audio file compressor.
TTA Lossless Audio Compressor Rate
A lossless codec developed in Russia originally for radio telescope data. Apparently that specialized codec turned out to be good on audio data as well. Distributed under a free license.
OptimFROG – IEEE Float Rate
A lossless compressor for audio data stored as IEEE floating point data.
DualStream – Near Lossless Audio Compression Rate
DualStream is aimed at filling the big gap between perceptual coding and lossless coding. The goal is to offer real transparent audio coding (not only perceptually transparent) at half or less the bitrate generally used by lossless coding, and also to permit progressive consistent increase of the quality level, until lossless coding is reached. To eliminate the problem of choosing between lossless and near lossless, DualStream has an option to create a correction file, which may be eventually stored separately and used at a later time to restore the original. The advantage is that the two files (near lossless and correction) have together approximately the size of the lossless coded original file.
OptimFROG – squeezing the bits out of audio Rate
OptimFROG is a lossless audio compressor. Lots of claims for great performance!
OptimFROG 4.507 is shipping as of October, 2003. Features added since my last report include numerous bug fixes and performance tweaks. The author claims to have superior lossless compression ratios, includes numerous player plugins, and is free for non-commercial use.
Version 4.507 is shipping as of October, 2003.
Gr8 Player Rate
A free Win32 media player that can handle quite a few popular audio and video formats.
Reader Brian H. says: Incredibly fast, and has just the features that I need.
gtranscode Rate
From the web site: gtranscode is a GTK+ GUI (graphical use interface) front-end for transcode in order to make this powerful tool easier to use. transcode is a powerful video and audio processing tool that can read in just about any format of video and/or audio and convert to just as many different formats. In addition to transcode’s extremely flexible modular concept for reading/writing different formats and codecs, it can apply filters, do re-sampling, resizing, cropping, and more.
Version 0.1.5 is shipping in April, 2003.
Reader Erin S. raves about gtranscode: Excellent usability, easy to install, and not only supports all the major functions of transcode, but anything it doesn’t support, you can add manually…the most versatile transcode yet!
Monkey’s Audio Rate
This is a lossless audio compression format that has support for WinAmp and Windows Media Player. Retain perfect fidelity for your music recordings, at the cost of additional disk space.
Version 3.99 is shipping as of May, 2004.
Xbox Media Player Rate
Your Microsoft Xbox is a great gaming platform, but it also has the capability to do much more. What a bargain it would be if you could use it as a digital media player, serving up MP3 files across the network, perhaps with nice videos on the high-definition outputs. All this becomes possible with just two things. First, you need to get a copy of the free Xbox Media Player, which lets you play DVDs, Internet Radio, MP3 files, etc. Second, the hard part: you need to get an Xbox Modchip, which lets you bypass Microsoft’s security restrictions and do as you please with your hard-purchased computer.
Version 2.3 is shipping as of February 15, 2003.
The LPAC Homepage Rate
LPAC is a codec for lossless compression of 8, 12, 16, 20, and 24 bit audio files. It has cross-platform support for Windows, Linux and Solaris. Direct playback of LPAC files is possible with a Winamp plug-in. A satisfied user tells the DCL Compression on the material I use is superior to the FLAC encoder.
Hybrid Lossless Audio Compression Rate
WavPack allows you to losslessly compress (and restore) both 16 and 24-bit audio files in the .WAV format. Unlike “lossy” compression schemes (like MP3) that discard information, WavPack converts the audio data into a more compact form so that the restored files are digitally identical to the original source. It’s somewhat like the file compression portion of WinZIP except that it’s optimized for audio data. Like other lossless compression schemes the data reduction varies with the source, but it is generally between 25% and 50% for typical popular music and somewhat better than that for classical music and other sources with greater dynamic range.
FLAC Source Code Rate
Source code to the FLAC library, command-line encoder/decoder, and player plugins. FLAC is an open-source lossless audio codec.
MP3 to Ogg Rate
This is a suite of programs which will help you to convert your existing mp3 files into ogg. The suite includes a text and a graphical frontend. Requires mpg321, mp3info, oggenc, vorbiscomment (zenity for gui).
Lossless Audio Compression with LTAC Rate
LTAC allows for lossless audio compression of PCM coded audio signals (16 bit), i.e. decoding results bit for bit in the original bit stream of the PCM coded signal. In contrast to LTAC there exist a lot of lossy coding algorithms like MPEG, ATRAC and AC-3, which yield higher compression ratios but in any case lead to coding distortions – nothing for HiFi purists and professionals.
User comment: Please note that LTAC is not developed further; it has a successor called LPAC; the rating refers to LPAC which is really an excellent small program.
VLC – the cross-platform media player Rate
VLC is an Open Source multimedia player that supports your usual mix of audio and video formats. Support is currently included for MPEG-1, -2, -4, mp3, ogg, and more. The site includes precompiled binaries for a really nice range of platforms, including Windows, Mac OS X, varios Linux flavors, and even BeOS!
Version 0.5.3 of this player is shipping as of April, 2003.
MPEG Audio Resources and Software Rate
Links to lots of info regarding the audio compression portions of the MPEG standards. This includes an overview, the MPEG Audio FAQ, pointers to resources, some free software, and test bitstreams.
Freeware Advanced Audio Coder (FAAC) Rate
The site says: FAAC is a MPEG4 GA (General Audio) encoder, that supports only the LOW and MAIN profile. Which are derived from MPEG2-AAC, adding some functionalities to further improve the bitrate efficiency (LTP and PNS).
Shorten Rate
Shorten is an audio compression program by SoftSound. Shorten is advertised as a low complexity audio coder that can compress in lossless or lossy mode. This is the home page with links to the download page. Includes source and binaries for DOS, Windows, and Linux. Evaluation version is available.
http://sourceforge.net/projects/mac3dec/ Rate Decodes AC-3 audio from DVDs, or QuickTime audio, and spits back AIFF, MP3, or AAC files.
Audio File Programs and Routines Rate The AFsp package contains audio file utility programs and a library of routines for reading and writing audio files. This ftp site contains three different releases of the software. Includes programs to compare, copy, filter, an analyze audio files. Also has resampling, LPC, and noise generation programs. Executables for Windows and Sun, with a wide variety of file formats supported.
QuickTime Alternative Rate QuickTime Alternative will allow you to play QuickTime (.mov .qt) files. This way there is no need to install the offical QuickTime Player. It also supports QuickTime content that is embedded in webpages. The QuickTime plugins include iPIX and QuickTimeVR.
Real Alternative Rate Real Alternative will allow you to play RealMedia files without having to install the official RealPlayer. You do need a media player that is capable of playing RealMedia files. The included Media Player Classic supports it. Supported are RealAudio (.ra .rpm), RealVideo (.rm .ram .rmvb), RealText (.rt), and ReadPix (.rp). Not fully supported are: Streaming smil files (.smi .smil) and Realmedia embedded in webpages.
Media Player Classic Rate Media Player Classic is similar to Windows Media Player 6.4 but with features pertained to minimalist advanced users. It also supports DirectX 9 and VFW drivers for capture. It supports viewing through ActiveX controls of Real and QuickTime files.
SONARC: Digital Audio Compression, Version 2.1i Rate SONARC is an old DOS audio compression program that was apparently used in Ultima, a well known game.
Shorten Utilities (shnutils) Rate shnutils is a collection of 3 Perl scripts developed to assist in the process of using shorten to trade digital music. These scripts, which run on both Linux and Windows, facilitate compressing WAV files using shorten, and also in creating and verifying MD5 hashes.
Open Mash Rate The Open Mash Consortium supports the Mash streaming media toolkit and distributed collaboration applications based on the Internet Mbone tools and protocols. The consortium is funded by a grant from the National Science Foundation Internet Technologies Program (Grant ANI-9907994) and by contributions from consortium members.
MediaInfo Rate Supplies you with detailed info about the attributes of all sorts of media files, naturally including MP3, AVI, WAV, MPEG2, and much, much more. Looks to be Win32 only.
flac2ogg Rate A perl script to convert FLAC or Shorten files to Ogg Vorbis.
Malcom Taylor’s Home Page Rate This link takes you to Malcom’s RKAU program, a lossless audio compressor. Malcom’s page says it often beats WA in max mode, at double the speed.
Symbian OggPlay Rate OggPlay is an Ogg vorbis audio player for smartphones. I started working on this project in early April 2003. The 1st version for the SonyEriccson P800 was released end of April. Many people have contributed localized versions, new skins, documentation, and are helping with porting the application to other phones since then. OggPlay has become a true open source project
GermaniXEncoder Rate GermaniXEncoder is a universal Transcoder for various sound formats like MP3, MP2, Real Audio, WMA, Ogg Vorbis, ALF2CD, DSP, GSM, G.721, G.723, G.726, RAW, PCM, ADPCM, uLaw, aLaw, MPC, and Monkeys Audio. In addition, the Encoder has a transformer for some transforming features, an Audio Recorder for recording from all input sources to mp3, mp2, pcm, adpcm, wma and ogg-vorbis. You can also split large MP3 files with their CUE sheets into songs.
Version 1.80.1195 RC2 was shipping as of Februaru, 2002.
FlacPack – Free lossless instrument file compression Rate This project aims to define a standard for the lossless compression of MIDI patch files. From the title, you might guess that the lossless audio compression is performed using FLAC – other binary data is compressed w/zlib.
Shorten fork Rate This is the free version of Shorten, which was forked from the commercial version from SoftSound. Not sure about all the legalities here, but I don’t think SoftSound is actively selling the commercial version, so this may be your only choice.
Foobar2000 Rate Foobar2000 is a relatively new audio player for Windows PCs. It seems to be attracting a little bit of interest among the literati, perhaps because it is mostly open sourced. It has a nice list of features, including tremendous list of codec support, as well as some unusual ones, such as the ability to play files in Zip archives.
DirectShow MediaPlayer in C# Rate This article shows how to play a Media File in a C# Windows Application.
A Basic Media Player Rate This project on the the Code Project web site shows you how to build a roll-your-own media player for Win32, using the standard multimedia API.
OggMux Rate This open source project is an attempt to create a replacement for GraphEdit, a tool Microsoft provides in the DDK.
Yet Another Time Machine Rate When listening to recordings of human speech (like audio books, conference recordings, …) it can be useful to have the ability to adjust the playback speed without changing the pitch of the recording. This simple command line program can do this for you. Playing a audio book at 150% of its original tempo is still intelligable and saves time, therefore the name of the program.
OGMtools Rate A set of tools to manipulate OGG Media Streams. The command line tools provide information about the stream, and allow you to extract from or create/merge streams.
Version 1.0.2 is shipping as of May, 2003.
jetAudio Rate Another company determined to swim upstream with a commercial media player. Although in this case, jetAudio Basic is free, jetAudio Plus is the the commercial product. You’ll pay for the upgrade if you decide you need support for creating MP3 and MP3Pro files, broadcasting MP3 files, and converting files to MP3 or MP3Pro.
jetAudio has a nice looking UI with some alternative skins. Version 5.01 is shipping as of March, 2003.

Helix Client Rate RealNetworks has created a semi-freeware project dedicated to creating a highly capable multmedia client for UNIX and Linux systems.
BonkEnc Rate BonkEnc is an audio CD ripper and an encoder for various audio formats. It can produce Ogg Vorbis, MP3 and BONK files. More formats are available through plug-ins.
FLAC – Free Lossless Audio Coder Rate FLAC is an open-source project which specifies a lossless compressed audio format and provides an encoder, decoder, and several player plugins. Aside from yielding better compression than Shorten, the format supports sample-accurate seeking and many other features useful for streaming and archival.
Reader Colin B. says: Incredible lossless audio compression, depending on the source, of course. I have seen high-quality speech recordings compressed to 10% of the original size, losslessly..
FLAC 1.1.0 released in January, 2003. A good roster of new features for this coder, including updates for libraries and plugins.
cwenc – MP3 & Ogg Vorbis Encoder for Cakewalk Rate The cwenc utility is primarily a tool for musicians working with Cakewalk music production software, such as Home Studio and Sonar. cwenc enables you to export your original music to a compressed audio file format, such as MP3 or Ogg Vorbis, from within the mentioned Cakewalk products. cwenc is a direct replacement for the time-limited demo-version of Cakewalk’s commercial MP3 encoder program, which is packaged with both Home Studio and Sonar.
Helix DNA Client Rate Real is making their client software available in an Open Source program. Download this software and you can develop your own MP3 player! Free of royalties if you are distributing it for free – commercial products pay a royalty.
Project: streamTranscoder Rate A rather terse description on SourceForge: Stream transcoder will be designed for use in relaying and converting streaming audio between various formats. MP3 and Vorbis will be supported. In Beta 4 as of September, 2002.
crip Rate From the web site:crip is a terminal-based ripper/encoder/tagger tool for creating Ogg Vorbis/FLAC/MP3 files under UNIX/Linux. It is well-suited for someone seeking to make a lot of files from CDs and have them all properly labeled and professional-quality. One thing to note is that the author of this free package has removed MP3 support, and limits you to Ogg Vorbis or FLAC for encoding.
Version 3.4 is shipping as of April, 2003.
Freedom Audio Rate FreedomAudio is a free Open Source package that lets you stream MP3 and Ogg Vorbis files from your web site. It renders audio using a small Java plugin. The nice part about using a plugin is that you only have to download an install this once. Freedom Audio also now supports a plugin-free mode, but apparently this results in reduced fidelity.
Version 1.08 Build 20 shipped in April, 2003.
http://movix.sourceforge.net/ Rate Directly from the MoviX web site:
The MoviX project is a series of three different tiny Linux CD distributions containing all the software to boot from a CD and play multimedia files through MPlayer, the best multimedia player in the Unix world:
eMoviX: a micro Linux distro meant to be embedded in a CD together with all video/audio files you want, so that the CD will be able to boot and automagically play all files;
MoviX: a mini CD Linux distro able to boot directly from CD and load in RAM a console interface to MPlayer. From the interface you can easily play DVDs, VCDs, audio/video files Audio CD, internet radios, TV, you name it!
MoviX2:same as MoviX, but it makes use of X and makes use of the nice MPlayer GUI.
Supported formats are all formats supported by MPlayer, most noticeably DivX but more in general any AVI, MPG, QuickTime, MP3, OGG/VORBIS and a few others.
eMoviX is at release 0.8.0rc1, MoviX is at 0.8.0pre2, and MoviX2 is at pre0.3.0pre2 as of April, 2003.
Vlorb Rate Vlorb is a high-quality Audio CD to Ogg Vorbis encoder. It does this by operating as a console front end to cdparanoia and CDDB on Linux systems.
Vlorb 1.0pre9 shipped at the end of March, 2003.
SoX – Sound Exchange Rate SoX aims to be the Swiss Army Knife of sound processing programs. It shows up on the data compression radar by virtue of the fact that SoX is able to convert between a wide variety of compressed formats, ranging from MP3 and Ogg to ADPCM and linear PCM. SoX has ports to a really nice variety of platforms, including Win32, Linux, NetBSD, and more.
Release 12.17.4 was shipping as of March, 2003.
Papers/Documentation

Technical audio papers Rate
A nice set of papers on audio coding. Includes goodies such as the ISO standards on MPEG-2 part 3 audio coding.
MPEG Audio Resources and Software Rate
Links to lots of info regarding the audio compression portions of the MPEG standards. This includes an overview, the MPEG Audio FAQ, pointers to resources, some free software, and test bitstreams.
Shorten Technical Report Simple lossless and near-lossless waveform compression Rate Technical report CUED/F-INFENG/TR.156 , Cambridge University Engineering Department, by Tony Robinson. A somewhat terse technical report describing some of the theory behind the design of the Shorten program.
Ogg Vorbis Documentation Rate This page contains links to a wide variety of Ogg Vorbis documents, including specifications, programming guides, and technical discussions.
Lossless Transform Coding of Audio Signals. Rate M. Purat, T. Liebchen, P. Noll: Lossless Transform Coding of Audio Signals. 102nd AES Convention, Munich, 1997. A PostScript file.
Signal Compression Lab Rate UCSB research activities, including speech coding, audio compression, video coding. Lots of links to demos and publications.
New Audio Coding Method Perfect for Internet Rate Les Atlas at the University of Washington has developed a new method for coding speech and music for transmission over slow lines. The technique, called fine-grain scalable audio encoding, prioritizes the most important part of the signal, allowing reconstruction at the remote end even if the face of lost packets.
Compression Technology in Multimedia Rate Lots of information on this site concerning compression of still pictures, moving pictures, and audio. Much of the site is devoted to comparisons of a few different algorithms. A report section draws a few conclusions about the whole thing.
Patents/Licenses

Dolby Laboratories Announces MPEG-4 AAC Licensing Program Rate This press release from Dolby seems to say that they will be the licensing point of contact for MPEG-4 audio applications.
Redistributing Windows Media 9 Series Components Rate The rules from Microsoft on what you can and can’t distribute from Windows Media 9.
Results

Lossless Compression of Audio Rate
My particular interest is in delivery of music via the Net – with compression which does not affect the sound quality at all. I am primarily interested in compression ratios, not speed of the programs. I think this is the first web site devoted to listing all known lossless audio compression algorithms and software – please email your suggestions and I will try to keep it up-to-date.
ASF vs. MP3 vs. RA-G2 vs. VQF Rate
A comparison of various lossy audio compression schemes. Panos Stokas provides his take on the whole situation, and includes tons of links to files, articles, and more food for thought. Most readers seem to like this web page, but one reader had this negative comment: This website is patently and fatally flawed to the nth degree. Nothing but misconception and conjecture with no real basis in scientific analysis. Very misleading to the uneducated in audio compression.. Another reader says Just reading “However, we have not found a single implementation that did not produce serious amounts of distortion in our testing sample. Nobody seems interested any longer.” about AAC of all things, makes it apparent that this guy has no idea what he’s talking about or what he’s doing.
SoundExpert Rate
This web site aims to provind blind quality testing of sound codecs. The site is just being launched at this time (3/2002), and is currently testing eight codecs.
Update: As of 8/2002, a few new codecs were added to the test suite: Ogg Vorbis 1.0, MPEG-4 Audio for QuickTime, and the PsyTel MPEG-4 AAC codec.
Ogg Vorbis Wins a Listening Test Rate This German news item reports on a test that pitched Ogg Vorbis against MP3, Window Media, AAC, and RealAudio. My Babelfish translation says In particular with 64 kBit/s Ogg Vorbis could convince and left the entire prominent competition behind itself. I think that means it won!
Windows Media 9: Better sound, smaller files Rate Josh Taylor of ZDNet did a quickie informal comparison of the new Windows Media 9 format and gives it a thumbs-up.
Discussion of Audio Compression Rate A great discussion of audio compression, which includes the results fo the 64 Kbps listening test.
Analysis of Microsoft Audio Codec Rate Real takes a whack at their chief competitor, Microsoft. Looks like they put some time and effort into this.
Listening Test Using Male Opera Voice Rate A set of subjective tests of various encoders.
Audio and Video Formats Rate PC Magazine used a jury to compare the codecs used in several popular media players, with interesting results.
Roberto’s public listening tests page Rate Roberto Amorim is a familiar and friendly presence on the Hydrogen Audio board. This link points to the many audio compression listening tests he has conducted. These include evaluations of AAC and MP3 encoders at a rew different rates.
Russian

AC3Filter Rate A DirectShow filter which will allow you to play AVI files containing AC3 encoded audio. A nice stream of releases with steady improvement.
Version 0.66b is shipping as of March, 2003.
Source Code

Kexis Rate
An open source lossless audio file compressor.
Hawk Software HawkVoice Rate
HawkVoice is a game oriented, multiplayer voice over network API released under the GNU Library General Public License (LGPL), with support for Linux/Unix and Windows 9x/ME/NT/2000. It is designed to be a portable, open source code alternative to DirectPlay(R) Voice in DX8.
FLAC Source Code Rate
Source code to the FLAC library, command-line encoder/decoder, and player plugins. FLAC is an open-source lossless audio codec.
Freeware Advanced Audio Coder (FAAC) Rate
The site says: FAAC is a MPEG4 GA (General Audio) encoder, that supports only the LOW and MAIN profile. Which are derived from MPEG2-AAC, adding some functionalities to further improve the bitrate efficiency (LTP and PNS).
Wax Audio Compression Rate
An ad hoc audio compression algorithm implemented in Visual Basic.
Audio Signal Processing Software Rate
Includes editing software, file formats and converters, codecs, and links. This page is at the University of Hannover, Germany. While there appears to be a wealth of software on this site, it would appear that you need special privileges to get access to ti.
CSharp Windows Media Format SDK Translation Rate In this article I describe a translation of most of the WMF SDK interfaces, data structures, constants, functions into C#. NOTE: Digital Rights Management (DRM) support is not included in this translation.
FFT of waveIn audio signals Rate Using your Windows PC to capture audio and perform an FFT on the captured sample.
DirectShow MediaPlayer in C# Rate This article shows how to play a Media File in a C# Windows Application.
Windows Media Audio compressor Rate A managed C++ program to compress audio using the Windows Medai Audio codecs.
Helix DNA Client Rate Real is making their client software available in an Open Source program. Download this software and you can develop your own MP3 player! Free of royalties if you are distributing it for free – commercial products pay a royalty.
Spanish

BonkEnc Rate BonkEnc is an audio CD ripper and an encoder for various audio formats. It can produce Ogg Vorbis, MP3 and BONK files. More formats are available through plug-ins.
Standards

The CWI Audio File Formats Guide Rate Useful links to information describing audio file formats.
Real embraces open-source Ogg Vorbis Rate Real Networks is going to add support for the Ogg Vorbis audio format in their client software, ZDNet reports. This could go a long way towards legitimizing the upstart competitor to MP3.
The AC3 Audio Compression Standard Rate This is a copy of the AC3 Audio compression standard from the Advanced Television Systems Committee (ATSC.) It’s nice to see a standards committee that is able to make their documents freely available to the public.
Tutorials, Reference, Presentations

AudioCodingWiki Rate
A nice set of links to AudioCoding information. Since this is a Wiki site, it is highly collaborative – registered users can provide updates and modifications to the site at will. (I think.)
A comparison of Internet audio compression formats Rate
A good comparsion chart showing the relative merits of various audio formats. Includes links to definitions and other support information for each format.
An Experimental High Fidelity Perceptual Audio Coder Project in MUS420 Win 97 Rate
A paper describing an experimental audio coder developed as some sort of class project.
ASF vs. MP3 vs. RA-G2 vs. VQF Rate
A comparison of various lossy audio compression schemes. Panos Stokas provides his take on the whole situation, and includes tons of links to files, articles, and more food for thought. Most readers seem to like this web page, but one reader had this negative comment: This website is patently and fatally flawed to the nth degree. Nothing but misconception and conjecture with no real basis in scientific analysis. Very misleading to the uneducated in audio compression.. Another reader says Just reading “However, we have not found a single implementation that did not produce serious amounts of distortion in our testing sample. Nobody seems interested any longer.” about AAC of all things, makes it apparent that this guy has no idea what he’s talking about or what he’s doing.
Codecs 101 for Microsoft Windows Media Technologies Rate This article from Microsoft’s Knowledge Base talks about the role of the codec in Microsoft’s Media Technologies.
Discussion of Audio Compression Rate A great discussion of audio compression, which includes the results fo the 64 Kbps listening test.
MPEG-4 AAC Rate This article from EE Times talks about the changes made to the Advanced Audio Coding portion of the standard during the change from MPEG-2 to MPEG-4.
Wikipedia entry: Vorbis Rate This Wikipedia entry describes the Vorbis codec, used in the open music codec Ogg Vorbis. Overview, a few interesting links, not much detail.
Analysis of Microsoft Audio Codec Rate Real takes a whack at their chief competitor, Microsoft. Looks like they put some time and effort into this.
Audio Compression Rate Course notes on audio compression. Discusses simple compression methods, then psychoacoustics and MPEG Audio.
Signal Compression Lab Rate UCSB research activities, including speech coding, audio compression, video coding. Lots of links to demos and publications.
CSharp Windows Media Format SDK Translation Rate In this article I describe a translation of most of the WMF SDK interfaces, data structures, constants, functions into C#. NOTE: Digital Rights Management (DRM) support is not included in this translation.
FFT of waveIn audio signals Rate Using your Windows PC to capture audio and perform an FFT on the captured sample.
DirectShow MediaPlayer in C# Rate This article shows how to play a Media File in a C# Windows Application.
Optimizing Microsoft Windows Media Services 9 Series Rate An article from Microsoft giving you the lowdown on the best way to use all the tools shipping with Windows Media 9. This includes basic guidelines on setting up a streaming media system, comparison to Media Services 4.1, locations of bottlenecks, performance evaluation, and advanced tuning tips.
Windows Media Audio compressor Rate A managed C++ program to compress audio using the Windows Medai Audio codecs.
Windows Media 9 Series reviewed Rate This site collects information, links, and review on Windows Media 9. Includes some detailed information on the codecs that are part of the new package.
Windows Media Metadata Usage Guidelines Rate Digital media needs metadata to be supremely useful. For example, wouldn’t it be nice if your CD player showed you artist, album, and track information while it was playing a song? MP3 tracks have ID3 tags to supply this information, but naturally, Microsoft has created an extensive set of APIs for embedding metadata in all types of media. This article will bring you up to speed on metadata support for media encoding, playback, and more.
Guide to Capturing, Cleaning, and Compressing Video Rate Matt Woodward has written an article for Ars Technica that gives a good rundown on capturing and compressing video. There’s a great deal of detail here, which you should be able to use to walk through the process, even if you are a rank beginner.
Audio File Format FAQ Rate This FAQ provides good information about various audio file formats, which naturally includes quite a few compressed formats. It also has a few links to other relevant pages.
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Backup

Compression programs that are oriented specifically towards backup features.
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Commercial Libraries

SuperCool ZIP Backup Rate SuperCool Zip Backup software is a data backup,restore and file synchronization program. You can use any drive in your system to store the backup files in standard Zip format that can be transferred to remote machine by FTP or Email. It can also compare and synchronize files or folders.
Version 1.61 is shipping as of May, 2003.
Commercial Programs

Argentum Backup Rate
This backup program stores your data in standard Zip files, created either manually or automatically. The usual host of backup features are supported, such as the ability to backup the registry, E-mail messages, your address book, and so on. You can download a 15-day trial version of this commercial program.
It appears that version 2.10 of this program shipped in January, 2004.
Backup32 Rate A Win32 backup program that stores files in a Zip compatible format.
Automatic File Archiver by JSPayne Rate An archive manager that has some built in functionality that helps you with your backup requirements. Automatic archiving in the trusty Zip format.
AM-Zip Rate Lots of folks (including me) perform system backups into Zip archives. Over the years I became leery of proprietary formats used by various manufacturers of tape drives, removable disks, etc. Zip files give me a much better feeling, and make it a lot easier to browse through my backups. Martin Aignesberger must feel the same way, because he has created a product that performs daily backups into Zip files. This is a commercial product, but he does offer a 30 day free evaluation.
Back4Win Backup Software Rate A backup program that uses the standard Zip format for compression. Yes, you can do backups with just a Zip program, but then you wouldn’t get all the cool options here, including disk spanning options, a nice GUI, password options, and more. This product comes in a freeware and shareware version.
Back4Win 2.5 and Back4Win 2.7 are shipping as of April, 2003.
Zip Backup to CD Rate A backup program that uses the standard Zip format. Supports complete system restore for Windows ME and 9x. Version 3 will have built in CD and DVD burning support, eliminating the need for an external burner program.
Version 2.34 is shipping as of March, 2003.
Azguard Rate Another backup program that is based around the Zip standard. Supports deflate64, spanning, and other advanced Zip features. This is Win32 shareware.
Version 2.5.4.53 shipped in December, 2003.
ZipBackup Rate Another Win32 backup program. 30 day free trial, but you have to pay up after that.
Back2zip Rate A shareware backup program that saves your stuff to the Zip format. We like that.
TurboZip Rate TurboZIP is an Archive, E-Mail Manager and Auto Backup tool. It opens major archive and E-mail formats. It offers the unique capabilities to internally view, print, copy, launch, and virus scan files within ZIP and E-mails without unzipping; unique ZIP Set and Multi-threading operation for simultaneous zipping, unzipping, auto backups..
TurboZip 5.1 appears to have been released sometime around January, 2003. Unfortunately, the FileStream web site doesn’t provide any sort of release history for this product, so it’s impossible to determine exactly when the release shipped and what features were added in 5.1.
Italian

ZipGenius Rate Zipgenius is yet-another-archiver. Supports 21 different compression formats, plus a pretty long list of extras, such as FTP support, email, backup functions, and more. The long list of features might make you expect a price tag, but ZipGenius is in fact free!
Version 5.5.1.440 of ZipGenius is shipping as of June, 2004.
Links

Delphi Programming – Backup and Data Compression Rate The About.com guide to Delphi Programming has a section on Data Compression and Backup software that looks pretty useful. About.com is a search engine and link site that features pages edited and maintained by real live humans.
Non-Commercial Programs

DAR – Disk Archive Rate
A command line program for making backups of directory trees and files. This freeware is ported to Linux, Windows, and Solaris.
Version 2.0.2 shipped in December, 2003.
TaskZip Rate
Freeware program written in VB5 that automates system backup, using Zip format.
ZipGenius Rate Zipgenius is yet-another-archiver. Supports 21 different compression formats, plus a pretty long list of extras, such as FTP support, email, backup functions, and more. The long list of features might make you expect a price tag, but ZipGenius is in fact free!
Version 5.5.1.440 of ZipGenius is shipping as of June, 2004.
Back4Win Backup Software Rate A backup program that uses the standard Zip format for compression. Yes, you can do backups with just a Zip program, but then you wouldn’t get all the cool options here, including disk spanning options, a nice GUI, password options, and more. This product comes in a freeware and shareware version.
Back4Win 2.5 and Back4Win 2.7 are shipping as of April, 2003.
Peter’s Backup Rate Peters Backup is a program for backing up your important data files on to diskette, zip drive, fixed disk or CD/RW. It uses an extremely efficient compression algorithm. It keeps track of all versions of your files in full and incremental backups.
Version 1.16 is shipping as of June, 2004.
Jarchiver Rate This is an open source tool that is described as a Java based archiving tool that is ideal for housekeeping tasks such as backups, pruning and more. Part of the archiving task is the ability to create zip archives, which explains its presence here.
Version 1.0 of Jarchiver is shipping as of March, 2003.
Source Code

TaskZip Rate
Freeware program written in VB5 that automates system backup, using Zip format.
Spanish

ZipGenius Rate Zipgenius is yet-another-archiver. Supports 21 different compression formats, plus a pretty long list of extras, such as FTP support, email, backup functions, and more. The long list of features might make you expect a price tag, but ZipGenius is in fact free!
Version 5.5.1.440 of ZipGenius is shipping as of June, 2004.
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Benchmarks

Benchmarks are an important part of the data compression world. Performance against benchmarks is a good way to judge algorithms in a fair manner. The problem, of course, is selecting benchmarks that accurately model the needs of the eventual users of the algorithm
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Files

CCITT standard fax images Rate
TIFF versions of the CCITT images.
Waterloo BragZone test suite Rate
In the BragZone you will find the following:
A suite of test images, the “Waterloo Repertoire”.
Rate-Distortion plots for various compression codecs.
The data from which the above plots are derived.
Sample images at selected compression ratios.
Waterloo BragZone Rate
Comparing different image compression programs has always been difficult. As a suite of test images and a place for archiving results, the Waterloo BragZone hopes to overcome these problems. Central to the effort is the Waterloo Repertoire, a suite of 32 test images
PNG Suite from Willem van Schaik Rate
This is Willem van Schaik’s suite of PNG icons for testing PNG decoder engines, PNG viewers, and PNG browsers.
Project Runeberg Rate
A huge collection of Swedish language text files
Benchmark Images and Files Rate David Cary is a major link farmer. One of the sections of his massive Data Compression page has links to various images and files that are used in various benchmarks.
The British National Corpus Rate The British National Corpus (BNC) is a 100 million word collection of samples of written and spoken language from a wide range of sources, designed to represent a wide cross-section of current British English, both spoken and written.
The Canterbury Corpus Rate This is the home page for the Canterbury Corpus, a test suite designed to provide a standard set of files for lossless compressoion testing. You will find links to the actual files in the test suite, as well as papers and test results.
Silesia compression corpus Rate Sebastian Deorowicz decided to create a compression corpus of his own, attempting to overcome some of the deficiencies he sees in the old guard.
Links

The Art Of Lossless Data Compression Rate
A comprehensive set of tests on lossless data compression.
Benchmark Images and Files Rate David Cary is a major link farmer. One of the sections of his massive Data Compression page has links to various images and files that are used in various benchmarks.
Newsgroup Posts

Where can I find Lenna and other images? Rate
The comp.compression FAQ attempts to answer this for you.
Papers/Documentation

Neural Network Text Compression Programs and Papers Rate
A couple of programs using neural networks for compression, along with a couple of papers by the author. This area of data compression is definitely underserved, check out what’s here and see if neural networks deserve more attention than they are getting.
Update: This page appears to now have some links to general lossless benchmarking info.
The Calgary Corpus Compression Challenge Rate Leonid A. Broukhis puts his money where his mouth is by offering a cash prize for good, reproducible compression. He has paid out at least one modest prize.
The Calgary Corpus Rate This is the home page for the Calgary Corpus. This set of files has long been the standard used for comparison of various lossless compression techniques.
People

Jeff Gilchrist This is Jeff Gilchrist’s home page. Jeff is the curator of the Archive Compression Test, which presumably keeps him busy.
Results

Archive Comparsion Test 2.0 ACT – by Jeff Gilchrist. ACT is the Archive Comparison Test, a long running benchmark on well known archiving programs. Lots of good updates in May of 2002.
The Art Of Lossless Data Compression Rate
A comprehensive set of tests on lossless data compression.
Maximum Compression Rate
Werner Bergmans has created a new benchmark site that aims to show the best compression ratios possible for multiple file types, including English text, executables, graphics, and so on. Werner says he is running these tests with 80-100 programs for each file type!
Reader Werner B. says Useful site to compare results of different compression programs. Regularly updated.
Berto’s Compression Spreadsheet Rate
Comparisions of over 230 archivers, in handy Excel format, from Berto.
Reader Emiliano C. said “Wonderful! Great! Wonderful! Cool!”
Calgarry Corpus test results Rate A set of test results for files run against the Calgary Corpus. This set of test results are kept on the Canterbury web site so that they can be easily referenced for comparison purposes.
Compression Ratios Rate A set of benchmarks for lossless compression of various test sets, including the CCITT B&W images, the Calgary Corpus, and a Gray Scale set. Includes some dates for checking historical progression.
Source Code

Neural Network Text Compression Programs and Papers Rate
A couple of programs using neural networks for compression, along with a couple of papers by the author. This area of data compression is definitely underserved, check out what’s here and see if neural networks deserve more attention than they are getting.
Update: This page appears to now have some links to general lossless benchmarking info.
Standards

CCITT standard fax images Rate
TIFF versions of the CCITT images.
Swedish

Project Runeberg Rate
A huge collection of Swedish language text files
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Books

This category covers all the books entered for all the various topics in the entire Data Compression Library. You can purchase all these books directly from Amazon.com by clicking on the links on this page. If you do so, you will help support this page by generated a small commission on the sale.
[ Deja News ] Search compression newsgroups for references to this topic
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Audio

Digital Compression for Multimedia: Principles & Standards Rate Jerry Gibson, Toby Berger, Tom Lookabaugh, Rich Baker and David Lindberg. Drawing on their experience in industry, research, and academia, this powerful author team combines their expertise to provide an accessible guide to data compression standards and techniques and their applications
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Coding

Source and Channel Coding: An Algorithmic Approach by John B. Anderson Rate
Source and Channel Coding: An Algorithmic Approach provides in-depth coverage of coded communication with the first unified treatment of trellis coding and modern bandwidth-efficient coding
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Source Coding Theory by Robert M. Gray Information Systems Laboratory, Stanford University, CA, USA Rate
Hardbound, ISBN 0-7923-9048-2 October 1989, 208 pp. Part of the Kluwer International Series in Engineering and Computer Science.
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Data Compression

The Data Compression Book The home page of The Data Compression Book. This is an introductory text oriented towards practical programming.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Mark Nelson Mark Nelson’s home page, with links to his books and articles.
Data Compression: The Complete Reference, 2nd edition Rate
by David Salomon. This book is intended to provide an overview of the many different types of compression: it includes a taxonomy, an analysis of the most common systems of compression, discussion of their relative benefits and disadvantages, and their most common usages.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Which books should I read? Rate
An answer to this question from the comp.compression FAQ.
Managing Gigabytes, 2nd Edition – Witten, Moffat, and Bell Rate
The second edition of Managing Gigabytes: Compressing and Indexing Documents and Images by Ian H. Witten, Alistair Moffat, and Timothy C. Bell, is now available (May 1999), published by Morgan Kaufmann Publishing, San Francisco, ISBN 1-55860-570-3.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Introduction to Data Compression, Second Edition Rate
by Khalid Sayood, University of Nebraska, Lincoln. 2000 600 pages, $69.95, ISBN 1-55860-558-4. This is a college level introductory text that covers a very wide range of data compression topics.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Data Compression from The Scientist and Engineer’s Guide to Digital Signal Processing Rate
A sample chapter from The Scientist and Engineer’s Guide to Digital Signal Processing, which just happens to be on Data Compression. You can download this entire book for free from the web site.
However, if you wish to purchase the hardcopy, please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Compression Algorithms for Real Programmers by Peter Wayner Rate
“. Compression Algorithms for Real Programmers describes the basic algorithms and approaches for compressing information so you can create the smallest files possible.”
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Data and Image Compression: Tools and Techniques, 4E Rate
by Gilbert Held, Thomas R. Marshall. <
If you are interested in buying this book, please use the link on this page. Your purchase will help to support this site.
Introduction to Information Theory and Data Compression Rate Home page for the book: Introduction to Information Theory and Data Compression Darrel Hankerson, Greg A. Harris, and Peter D. Johnson Jr.
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Compression and Coding Algorithms Rate by Alistair Moffat and Andrew Turpin. This book is scheduled for publication in 2002 by Kluwer Academic Publishers. This site has a table of contents and some sample pages to peruse while you wait for it to be printed.
This book now shows up as available on Amazon.com. Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Introduction to Information Theory and Data Compression (Discrete Mathematics and Its Applications Series) Rate by Hankersson et. al. Hardcover – 330 pages (November 1997) CRC Press; ISBN: 0849339855. A textbook for upper-level or graduate course on compression. Please use the link on this page to purchase this book, it will help support the Data Compression Library.
Data Compression Bibliography Rate The University of Washington has a nice bibliography here, with pointers to books on Data Compression, VQ, Wavelets, and Information Theory.
Fractals

Fractals Everywhere Rate
by Michael F. Barnsley. A revised and updated textbook focusing on how fractal geometry can be used to model real objects in the physical world. DCL reader TJ says This is, in my experience, the best mathematics book I have ever seen
If you are interested in buying this book, please use the link on this page. Your purchase will help to support this site.
Fractal Image Compression : Theory and Application Rate
by Yuval Fisher (Editor). Featuring a collection of articles by twelve experts in the field of fractal image compression, this book contains the complete details of how to encode and decode images, offering working codes that are usable in applications. Includes some of the latest results in this field..
If you are interested in buying this book, please use the link on this page. Your purchase will help to support this site.
Fractal Imaging, by Ning Lu Rate
ISBN: 0124580106, April 1997, US Price: $55.95. The publisher says: Fractal Imaging presents the logic, technology, and various uses of fractal imaging by analyzing a complete, usable fractal image representation system. The book appears to be designed to help apply fractal imaging.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Fractal Image Compression Rate
by Michael F. Barnsley, Lyman P. Hurd, Louisa F. Anson (Illustrator). A sequel to Barnsley’s first book.
If you are interested in buying this book, please use the link on this page. Your purchase will help to support this site.
GIF – Compuserve’s Graphics Interchange Format

Compressed Image File Formats: JPEG, PNG, GIF, XBM, BMP by John Miano Rate
“Compressed Image File Formats is an appealingly compact and useful guide to some of today’s most popular file formats used for image data. For any programmer who needs to know how images are stored, this concise reference can serve as a really invaluable resource.”
Note that the source code for this book includes an independent implementation of a PNG codec, which may be one of a kind. Link to the source code on this page.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Image Compression

Managing Gigabytes, 2nd Edition – Witten, Moffat, and Bell Rate
The second edition of Managing Gigabytes: Compressing and Indexing Documents and Images by Ian H. Witten, Alistair Moffat, and Timothy C. Bell, is now available (May 1999), published by Morgan Kaufmann Publishing, San Francisco, ISBN 1-55860-570-3.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Image and Video Compression Standards Algorithms and Architectures, Second Edition Rate
by Vasudev Bhaskaran, Kluwer Academic Publishers, Boston Hardbound, ISBN 0-7923-9952-8, 472 pp., $97.50. This book describes the various standards in use today, including MPEG, JPEG, H.261, and so on.
Please use the link on this page to purchase the book through Amazon.com. Your purchase will help support this web site.
Sample pages on DCT Rate
Sample pages on line from the book Discrete Cosine Transform: Algorithms, Advantages, Applications by Kamisetty Ramamohan Rao, P. Yip. The first 6 pages of the book are excerpted here, giving a complete history of the DCT.
Compressed Image File Formats: JPEG, PNG, GIF, XBM, BMP by John Miano Rate
“Compressed Image File Formats is an appealingly compact and useful guide to some of today’s most popular file formats used for image data. For any programmer who needs to know how images are stored, this concise reference can serve as a really invaluable resource.”
Note that the source code for this book includes an independent implementation of a PNG codec, which may be one of a kind. Link to the source code on this page.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Bilddatenkompression/Image Data Compression Rate
Subtitled Basics, Standards and Wavelet-Based Algorithms for Image and Video Coding. This German-language textbook contains full source code (ANSI-C) of a wavelet-based image coder.
Image Compression Algorithms Rate
The book that accompanies the course of the same name. Russian-language submitter reports that the book has info on RLE, LZW, CCITT Group 3, Jpeg, Wavelet, and Fractal compression.
Digital Compression for Multimedia: Principles & Standards Rate Jerry Gibson, Toby Berger, Tom Lookabaugh, Rich Baker and David Lindberg. Drawing on their experience in industry, research, and academia, this powerful author team combines their expertise to provide an accessible guide to data compression standards and techniques and their applications
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Digital Image Compression Techniques (Tutorial Texts in Optical Engineering, Vol 7) Rate by Majid Rabbani and Paul W. Jones. This book shows up in at least one bibiblography, I would appreciate reviews from a reader.
Information Theory

Elements of Information Theory Rate by Thomas M. Cover, Joy A. Thomas. This is an introductory text on Info Theory, covering all the basics, which of course includes coding and data compression.
Bibliography of Claude Elwood Shannon Rate This bibliography is the best attempt at a complete record of all the written works of Claude Shannon, father of Information Theory.
Introduction to Information Theory and Data Compression Rate Home page for the book: Introduction to Information Theory and Data Compression Darrel Hankerson, Greg A. Harris, and Peter D. Johnson Jr.
Buy from Amazon.com
Claude Elwood Shannon : Collected Papers Rate According to the publisher, this contains all of Shannon’s published works, plus papers that were previously unpublished for various reasons, including wartime secrecy.
Information Theory, Inference and Learning Algorithms Rate This book by David MacKay can be downloaded chapter by chapter and printed out for free. No indication that you can buy a hardcopy, although Amazon.com claims it will be published in January, 2002. Please read this 600 page tome and provide a review for this space!
Update: The author tells me this book will be published in November, 2003. The book will remain viewable on his website!
Information Theory Rate by Robert B. Ash. This book gets a couple of five star ratings on Amazon.com. If you’re the type to pay close attention to your budget, you’ll like the fact that it sells for under $10!
Introduction to Information Theory and Data Compression (Discrete Mathematics and Its Applications Series) Rate by Hankersson et. al. Hardcover – 330 pages (November 1997) CRC Press; ISBN: 0849339855. A textbook for upper-level or graduate course on compression. Please use the link on this page to purchase this book, it will help support the Data Compression Library.
Data Compression Bibliography Rate The University of Washington has a nice bibliography here, with pointers to books on Data Compression, VQ, Wavelets, and Information Theory.
JPEG

Sample pages on DCT Rate
Sample pages on line from the book Discrete Cosine Transform: Algorithms, Advantages, Applications by Kamisetty Ramamohan Rao, P. Yip. The first 6 pages of the book are excerpted here, giving a complete history of the DCT.
Compressed Image File Formats: JPEG, PNG, GIF, XBM, BMP by John Miano Rate
“Compressed Image File Formats is an appealingly compact and useful guide to some of today’s most popular file formats used for image data. For any programmer who needs to know how images are stored, this concise reference can serve as a really invaluable resource.”
Note that the source code for this book includes an independent implementation of a PNG codec, which may be one of a kind. Link to the source code on this page.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Bilddatenkompression/Image Data Compression Rate
Subtitled Basics, Standards and Wavelet-Based Algorithms for Image and Video Coding. This German-language textbook contains full source code (ANSI-C) of a wavelet-based image coder.
JPEG-2000

Jpeg2000 : Image Compression Fundamentals, Standards, and Practice Rate
by David S. Taubman, Michael W. Marcellin. This rather pricey book is listed as a reference for engineers and researchers who want to understand the JPEG2000 standard. Taubman is the author of the Kakadu tools, which are included on the CD (licensing terms unknown.) Use the link on this web page to buy the book – you’ll help keep this site on line.
Lossless Compression

Universal Compression and Retrieval Rate
By Rafail Krichevsky, Institute of Mathematics, Russian Academy of Sciences, Novosibirsk University, Russia. This volume constitutes a comprehensive self-contained course on source encoding.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Reader Yuriy R. says: A concise and rigorous course on universal source coding and universal information retrieval. Only suitable for math. oriented readers, graduate students, and researchers in these fields. Engineers expecting to find source-code of data compression algorithms shall look elsewhere.
MPEG

Bilddatenkompression/Image Data Compression Rate
Subtitled Basics, Standards and Wavelet-Based Algorithms for Image and Video Coding. This German-language textbook contains full source code (ANSI-C) of a wavelet-based image coder.
Efficient Algorithms for MPEG Video Compression Rate by D. T. Hoang and J. S. Vitter Efficient Algorithms fo MPEG Video Compression, John Wiley & Sons, New York, NY, 2002. This book has just started shipping, I haven’t seen a copy or heard any feedback yet. Provide some if possible!
If you want to buy this book, please use this link to order. Your purchase from Amazon.com will help support this web site.
PNG

PNG: The Definitive Guide by Greg Roelofs Rate
As the title says, this is the definitive guide to the PNG format. Greg discusses all aspects of PNG, including graphics programs, progrmaming with libpng, compression, filtering, the works. This is a must-read book if you want to support this free graphics format.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Compressed Image File Formats: JPEG, PNG, GIF, XBM, BMP by John Miano Rate
“Compressed Image File Formats is an appealingly compact and useful guide to some of today’s most popular file formats used for image data. For any programmer who needs to know how images are stored, this concise reference can serve as a really invaluable resource.”
Note that the source code for this book includes an independent implementation of a PNG codec, which may be one of a kind. Link to the source code on this page.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Quantization

Vector Quantization and Signal Compression by Allen Gersho Rate
Kluwer Academic Publishers, Boston Hardbound, ISBN 0-7923-9181-0 November 1991, 760 pp.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Vector Quantization and Signal Compression Rate
by Allen Gersho and Robert M. Gray. This book shows up in at least one bibiblography, I would appreciate reviews from a reader.
Data Compression Bibliography Rate The University of Washington has a nice bibliography here, with pointers to books on Data Compression, VQ, Wavelets, and Information Theory.
Speech

Computer Speech : Recognition, Compression, Synthesis Rate by Manfred R. Schroeder. How about a customer review of this book?
Digital Processing of Speech Signals Rate by Lawrence R. Rabiner, Ronald W. Schafer. A basic overview of how to use DSP to deal with speech.
Video

Video Demystified Rate
This book promises to tell you everything you need to know about video, which includes pertinent compression issues: H.261, H.263, MPEG-1, MPEG-2, and other video formats. Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Image and Video Compression Standards Algorithms and Architectures, Second Edition Rate
by Vasudev Bhaskaran, Kluwer Academic Publishers, Boston Hardbound, ISBN 0-7923-9952-8, 472 pp., $97.50. This book describes the various standards in use today, including MPEG, JPEG, H.261, and so on.
Please use the link on this page to purchase the book through Amazon.com. Your purchase will help support this web site.
Digital Compression for Multimedia: Principles & Standards Rate Jerry Gibson, Toby Berger, Tom Lookabaugh, Rich Baker and David Lindberg. Drawing on their experience in industry, research, and academia, this powerful author team combines their expertise to provide an accessible guide to data compression standards and techniques and their applications
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Video Codec Design Rate Web page for a new book, Video Codec Design, to be published by Wiley in March 2002. Video Codec Design takes a design-based approach to image and video compression. The book covers the JPEG, JPEG2K, MPEG1/2/4 and H.261/3/L standards and gives detailed guidance on designing image and video compression applications.
DataCompression.info reader Eduardo M. said this was very easy to read and understand, but he would have liked some code examples.
Wavelets

Multiresolution Signal Decomposition: Transforms, Subbands, Wavelets Rate
by Ali N. Akansu, Richard A. Haddad. This book covers the areas you need to know in order to understand much of modern singal compression techniques. The second edition was issued in January, 2001.
Bilddatenkompression/Image Data Compression Rate
Subtitled Basics, Standards and Wavelet-Based Algorithms for Image and Video Coding. This German-language textbook contains full source code (ANSI-C) of a wavelet-based image coder.
Data Compression Bibliography Rate The University of Washington has a nice bibliography here, with pointers to books on Data Compression, VQ, Wavelets, and Information Theory.
Wavelets and Subband Coding Rate by Martin Vetterli and Jelena Kovacevic. This book is a hefty academic tome, described on this web page as: a comprehensive and unified presentation of discrete and continuous wavelets, filter banks and subband coding, as well as multiresolution signal processing, is given. It is intended for practitioners and researchers in the fields of signal processing and telecommunications, as well as applied mathematics and computer vision..
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Burrows-Wheeler Transform/Block Sorting

Block Sorting treats a body of text as a large block of strings. The strings can be sorted using a reversible algorithm of some kind, yielding a more compressible dataset. The best known example of this technique is the Burrows-Wheeler Transform, or BWT.
The Burrows-Wheeler Transform refers to a reversible transformation that can make a given text more compressible. Once this transform has been applied, the text can be compressed with a combination of Move to Front encoding followed by an entropy encoder.

[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Commercial Libraries

Xceed Streaming Compression Library The Xceed Streaming Compression Library is a high-performance “raw” compression library. It offers the ability to compress and decompress streaming data, buffers, strings or single files and supports multiple compressed data formats. Unlike the Xceed Zip Compression Library, this ultralight library doesn’t offer Zip file handling capabilities.
Xceed Zip Compression Library A feature-rich COM/ActiveX and DLL component for adding Zip and Unzip to your Windows apps with minimum effort. Includes full documentation with many samples and examples for VB, VC++, Delphi and C++Builder to get you started quickly. Supports the latest zip file format updates including Deflate64 compression and Zip64 headers. Also includes BZip2 compression which is excellent for compressing XML data.
UPL Compression : the complete professional toolkit Rate
The UPL Compression Library is a high-performance professional compression library. It offers the ability to compress and decompress data, buffers, strings or single files and features the latest innovations in data compression. The library offers eight extremely powerful compression algorithms. Dynamic Huffman, Arithmetic, BWT, Ppm and several Lempel Ziv flavors.
DataCompression.info user John G. had this to say: I was looking for adding a better compression to my Visual Basic project and it worked like a charm. The compression ratio is really good, better than Zip!
Sax.net Streaming Compression Rate Sax.net Streaming Compression helps you keep your data small and fast. Use high-performance compression and data compression code, using a class library that was designed from the ground up for integration with the Microsoft .NET framework.
In addition to being able to specify whether to prefer speed over size, Sax.net Compression offers you a choice of two compression algorithms: Industry-standard Deflate (ZIP) compression, and the newer Burrows-Wheeler (BZip2) transform, which generates especially great results when compressing XML data.

Commercial Programs

Compressia Rate
Compressia is a BWT-based archive utility with particularly high compression ratios. On Calgary, Canterbury, ACT-Text and ACT-Exe it surpasses all other BWT utilities. On Canterbury corpus it also surpasses all PPM utilities. Beta version 1.0 is available on the web site as of February, 2003.
DataCompression.info reader Juan L. said It is by far the best I’ve tried.
SBC Archiver Rate
The submitter said: SBC is Burrows Wheeler Transform based file archiver. It’s one of the fastest BWT implementations with high compression ratio. SBC also introduces a high security options with a number of strong encryption algorithms.
SBC appears to be shareware. Comment from a DCL user: Cool archiver; the author has made great effors to make it really fast and also added a lot of heuristics to behave well on multimedia data.
Transform Rate Transform is a BWT compressor written by Michael Bone. It supports a number of very interesting features, such as automatic Base 64 representation and image output. Shareware.
Version 1.02 shipped in October, 2003.
12Ghosts Zip Rate This package includes 12Zip and 12Zip2. The first version uses Zip compatible compression, and the second uses a BWT variant.
Version 7.0 of the package is shipping as of May, 2004
Finnish

SBC Archiver Rate
The submitter said: SBC is Burrows Wheeler Transform based file archiver. It’s one of the fastest BWT implementations with high compression ratio. SBC also introduces a high security options with a number of strong encryption algorithms.
SBC appears to be shareware. Comment from a DCL user: Cool archiver; the author has made great effors to make it really fast and also added a lot of heuristics to behave well on multimedia data.
German

Grundlagen des Burrows-Wheeler-Kompressionsalgorithmus This is another German preprint of Jürgen Abel describing the principles of the Burrows-Wheeler Compression Algorithm. An implementation of a BWT based compressor with a compression rate of 2.25 bps on the Calgary Corpus is presented. The paper will be published in the German journal “Informatik – Forschung und Entwicklung”, Springer-Verlag Heidelberg, Association for Informatics (Gesellschaft für Informatik eV.)
Verlustlose Datenkompression auf Grundlage der Burrows-Wheeler-Transformation This is a preprint of a paper by Jürgen Abel describing the functionality of a basic but quite fast Burrows-Wheeler compressor. Jürgen reports that this will be published in PIK, a German-language journal on Communications and Information Theory.
Italian

Giovanni Manzini Rate
Giovanni Manzini has published papers covering a few different topics in Data Compression, including several recent works on Burrows-Wheeler algorithms. He is currently an Associate Professor of Computer Science at the Universita degli Studi del Piemonte Orientale in the the most northern reaches of Italy.
Paolo Ferragina Rate
Paolo Ferragina’s research in data structures and string matching naturally lends itself to Data Compression and to the problem of indexing compressed data. See the link to his recent papers on indexing BWT compressed files. He is currently an Associate Professor of Computer Science at the University of Pisa.
Links

Burrows-Wheeler Transformation / Block Sorting (BWT) Jürgen Abel has done an enormous amount of research on the Burrows-Wheeler Transform, and has published the results on his web site. On this page you will find:
A summary of this compression technique.
Links to over 70 online papers.
Links to at least that many people involved in BWT research or development.
Extensive links to BWT source code.
This web page may now be the definitive source of information for this field.
The Sort Transformation by Michael Schindler Rate Michael Schindler’s page describing a sorting algorithm that was presented in a poster session at DCC ’97. Links to his source code, plus links to the paper and poster in postscript format. Update: Michael has made additional source code available.
Michael Walden’s Compression Pointers Rate A comprehensive set of compression pointers. Unfortunately, Michael is using some sort of software that makes bookmarking into his index impossible. So instead, you must link to the main page, shown here, and locate the links to “Data Compression”. Under that he has links to General Resources, Software, and Theory.
Newsgroup Posts

Distance Coding post Rate
A post by Edgar Binder discussing his distance coding algorithm. Distance coding is used in place of the MTF stage in BWT compression.
The Burrows-Wheeler block sorting algorithm Rate
The comp.compression FAQ provides some details.
BWT and different alphabet orders Rate A long thread dealing with a possible way to some improvement on BWT compression.
Paper on BWT for source estimation Rate A long and entertaining discussion of BWT compression in the comp.compression newsgroup.
Non-Commercial Libraries

Zzip – The New Compressor A new archiver that uses a BWT algorithm to achieve superior compression. The author has now released the source code to zzip under the GPL.
The bzip2 and libbzip2 official home page Rate
The home page for Julian Seward’s great BWT projects: a compression program and a library. A prelease of bzip2 1.0 was released 4/15/00
Block Sorting Compression Algorithm Rate This is an academic project. A library and a sample program will be developed, that will implement the Burrows-Wheeler compression algorithm, using C++ and templates. This is the same algorithm for BZip.
libbzip2 for WinCE Rate A version of libzip2 in source format for WinCE, along with demo code and project files. Ciprian Miclaus created this port along with one of zlib, and has made them available for all manking. Thanks Ciprian!
Embedded BWT Compression Rate Tom has posted his source code for embedded BWT compression. Basically, he’s trying to pull it off with low amounts of RAM.
Bzip2 classes Rate Gilad Novik created a pair of classes to compress and decompress data using the bzip2 format.
zipstream, bzip2stream: iostream wrappers for the zlib and bzip2 libraries Rate This article describes STL-compliant iostream implementations that compress and decompress using the deflate and bzip2 algorithms. It makes it really easy to use compressed streams in your C++ app.
Updated July, 2003, to fix a gzip header problem.
Updated August, 2003 to fix a couple of minor problems.
BWTCoder: Industrial strength BWT compression Rate This is a preliminary shot at creating an open source BWT compression engine. Things look very preliminary at this point with just a couple of files available for download and not much message traffic.
Non-Commercial Programs

Zzip – The New Compressor A new archiver that uses a BWT algorithm to achieve superior compression. The author has now released the source code to zzip under the GPL.
ABC – Advanced Blocksorting Compressor ABC is a free data compression program based on the Burrows-Wheeler transformation. The source code is free for academic, research and educational use as depicted in the Abel Public License (APL). The program is developed in DELPHI as a command line program just like GZIP.
Update: Jürgen has released the source code for ABC at long last! The Delphi source is available for download from the web site and can be used under his own APL.
Winimp – The Archiver for the 21st Century Rate
WinImp has been re-released as freeware. This archiver can create Zip files, and extract from the usual list of Zip, ARJ, RAR, and so on. It includes a couple of proprietary (BWT-based?) algorithms that purport to do well on text files.
DataCompression.info user Mike notes that It includes 2 very good compression methods and only the new versions of Winrar, Winace or Rk can compete with the compression ratios of Winimp.
DC Archiver Rate
DC is a BWT based archiver by Edgar Binder. Is it free? Not sure, but no source.
GRZip Rate
GRZip – is a high-performance file compressor based on Burrows-Wheeler Transform and Advanced Weighted Frequency Counting. It uses The Block-Sorting Lossless Data Compression Algorithm, which has received considerable attention over recent years for both its simplicity and effectiveness. This implementation has compression rate of 2.364 bps on the Calgary Corpus. The site has Windows, Linux, and Dos executables along with source.
szip homepage Rate
Szip is a freeware portable general purpose lossless compression program. It has a high speed and compression, but high memory demands (up to 20MB) too. The compression is done using a variant of blocksorting, which explains its rather high memory requirements.
Update: Michael Schindler has at long last posted the source code for szip.
The bzip2 and libbzip2 official home page Rate
The home page for Julian Seward’s great BWT projects: a compression program and a library. A prelease of bzip2 1.0 was released 4/15/00
BA 0.99b – 1999, a Blocksorting Arithmetic compressor Rate
Reputedly good BWT implementation, no source.
UHBC 1.0 Rate
UHBC is a blocksorting compressor optimized for high compression ratios. The program uses recent research results by S. Deorowicz and J. Abel for improved second stage processing after the BWT. Some extensions and sophisticated modeling provide top compression ratios, giving the best known result for Calgary Corpus (2.208 bps average). UHBC is free for non-commercial use. No source available.
Reader Grebnov I. had this to say: Compression is very good, but too slow + no source code..
M99 Rate This page is devoted to a new compressor called M99. The author says that M99 is a new type of statistical compressor that has speeds rivaling the fastest Huffman coders with ratios of the best statistical modeling programs. Good!
BZip2 for Java Rate Aftex Software makes a Java version of Bzip2. This includes input and output stream classes, which can be used in other Java applications. The program has both a GUI and command line interface.
Bzip2 mini-HOWTO Rate David Fetter wrote a Linux howto telling you how to compile, install, and use bzip2, the BWT-based freeware archiver.
WinBZip2 Rate WinBZip2 is an small freeware utility for working with files produced by bzip2 utility (usually it’s files with .bz2 extension) and also create such files. Main features include the compressing, decompressing and testing the integrity of bzip2 files.
YBS (blocksorting compressor) Rate YBS is a high-performance archiver based on Burrows-Wheeler Transform and distance coding modelling. It’s quite fast even on skew data and achives high compression ratio. Versions are posted here for DOS and Win32. It appears that the last update was in 2000.
UFUP Rate UFUP advertises itself as a “decompression utility that handles common Unix package formats such as bzip2, gzip, and tar.”
QLFC – Quantized Local Frequency Coding Rate Florin Ghido has developed a BWT archiver, here for the taking. I believe this is free.
bwtzip: A Linear-Time Portable Research-Grade Universal Data Compressor Rate bwtzip is an ongoing project, distributed under the GNU General Public License, to implement a Burrows-Wheeler compressor in standard, portable C++. It is research-grade in that it is highly modularized and abstracted, so that it is simple to swap out parts of the compressor without affecting anything else. This makes it easy to experiment with different algorithms at different stages of compression.
Looks like Steven T. Lavavej released a new version of bwtzip in early February, 2003. A wide variety of improvements, most of them in implementation – not visible to the end user. A description of recent changes is found here
BAR Rate BAR Archiver is a free, cross-platform file compression and archiving tool written in Java. It outperforms most of the popular file compression tools available as commercial utilities. Compression is based on Burrows Wheeler Transformation and modified Huffman entropy coder. The compression ratio is in par with most of the commercial grade compression utilities.
MacBzip2 Home Page Rate A port of Julan Seward’s bzip2 program to the Mac. It’s free and full source is included if you are the adventurous type.
bsdtar, libarchive Rate Libarchive is a programming library that can create and read several different streaming archive formats, including most popular tar variants and the POSIX cpio format. The bsdtar program is an implementation of tar(1) that is built on top of libarchive. It started as a test harness, but is quickly moving toward becoming a candidate system tar for FreeBSD
Papers/Documentation

Grundlagen des Burrows-Wheeler-Kompressionsalgorithmus This is another German preprint of Jürgen Abel describing the principles of the Burrows-Wheeler Compression Algorithm. An implementation of a BWT based compressor with a compression rate of 2.25 bps on the Calgary Corpus is presented. The paper will be published in the German journal “Informatik – Forschung und Entwicklung”, Springer-Verlag Heidelberg, Association for Informatics (Gesellschaft für Informatik eV.)
Burrows-Wheeler Transformation / Block Sorting (BWT) Jürgen Abel has done an enormous amount of research on the Burrows-Wheeler Transform, and has published the results on his web site. On this page you will find:
A summary of this compression technique.
Links to over 70 online papers.
Links to at least that many people involved in BWT research or development.
Extensive links to BWT source code.
This web page may now be the definitive source of information for this field.
Universal Data Compression Based on the Burrows and Wheeler Transformation: Theory and Practice by Bernhard Balkenhol, Stefan Kurtz, 1998. Yet another analysis of the algorithm. Any exciting conclusions? Click the rate link and you can tell me.
Verlustlose Datenkompression auf Grundlage der Burrows-Wheeler-Transformation This is a preprint of a paper by Jürgen Abel describing the functionality of a basic but quite fast Burrows-Wheeler compressor. Jürgen reports that this will be published in PIK, a German-language journal on Communications and Information Theory.
Text Preprocessing for Data Compression by Jürgen Abel and William Teahan. This paper looks at a few different techniques for preprocessing data before performing text compression, and compares the gains achieved when combining the preprocessors with PPM, BWT, and LZ algorithms.
Papers by Bernhard Balkenhol Bernhard seems to have written quite a few papers on data compression. A few of them are in German, a few in English. All in ps.gz format. Bernhard has links to published papers and preprints on this page, be sure to check them all.
Improvements to the Burrows-Wheeler Compression Algorithm: After BWT Stages This preprint of Jürgen Abel gives a short introduction into the BWCA field and proposes several improvements for the WFC stage and the IF stage. It further introduces a new RLE scheme for bypassing the run length information around the WFC stage. The paper is the basis of the BWCA program ABC and the revealed approach achieves a compression rate of 2.238 bps, which is the best result for a pure BWCA without any preprocessing before the BWT to date (March 2003).
Modifications of the Burrows and Wheeler Data Compression Algorithm by Balkenhol, Bernhard; Kurtz, Stefan; Shtarkov, Yuri M. The authors discuss some statistical qualities of BWT output and improve on the algorithm’s performance. This paper was presented at the 1999 Data Compression Conference.
David’s View of BWT David Scott occupies a unique niche in the world of data compression. He is very interested in how one can adapt existing compression technologies to be bijective, a term you can find defined on his web page. The stated motivation for this is to increase the difficulty of breaking an encrypted version of the file. On this page, David makes a first pass at modifying BWT to be bijective. He doesn’t quite get there, but feels that he has taken some good steps towards his goal.
Modifications of the Burrows-Wheeler Data Compression Algorithm Rate
by Balkenhol, Kurtz, and Shtarkov. A paper that was published at DCC 1999. Some thoughts about BWT and the context tree model, alphabet modification, modification of MTF, and Grouping of symbols.
NOTE:The file type would indicate that this is a compressed file, but it actually appears to be unencoded PS format.

Higher Compression from the Burrows-Wheeler Transform by Modified Sorting Rate
A paper by Brent Chapin and Steve Tate describing some improvements in BWT compression. The abstract says that compression can be improved by alphabet ordering and reflecting the sorted binary strings. This version is in PDF format, a PS format is available as well.
Improvements to Burrows-Wheeler Compression Algorithm Rate
A paper by Sebastian Deorowicz appears here, which claims to make improvements in efficiency to BWT compression, giving the best ratios of any BWT program on the Calgary Corpus.
A Block-sorting Lossless Data Compression Algorithm Rate
Burrows, M. and Wheeler, D.J., A Block-sorting Lossless Data Compression Algorithm, Digital Systems Research Center Research Report 124, May 1994. The original paper on BWT compression. This very effective compression technique was first described in this paper.
Michael Schindler reviewed it thus:Even through it is the first paper about blocksort it is still excellent literature for introduction to this method and its general ideas..
Note: after many years, the DEC web site hosting this paper finally disappeared, not surprisingly. The new link is via the CiteSeer search engine, which I hope is a permanent solution.
D.J. Wheeler’s FTP site Rate
Contains his implementation of the BWT algorithm, in the program bred. Along with this are some notes and papers on his implementation of BWT Current list of files: bexp.c bexp3.c bred.c bred.ps bred.ps.Z bred2 bred3.c bred3.ps exp.c huff.ps mintext.ps mintext.tex red.c tea.ps tub.ps wake.ps xtea.ps xxtea.ps
A Run Length Encoding Scheme For Block Sort Transformed Data Rate
A paper by Michael A. Maniscalco that desribes an RLE algorithm tailored for use with the BWT compression technique.
Hirosuke Yamamoto’s Papers Rate This page has links to online versions of Hirosuke Yamamoto’s papers on data compression. Papers here on block sorting, coding, and more. The papers are all published in English.
“Block Sorting Text Compression” by Peter Fenwick Rate A paper discussing BWT text compression in Proceedings of the 19th Australasian Computer Science Conference, Melbourne, Australia. Jan 31 – Feb 2, 1996.
“Improvements to the Block-Sorting Text Compression Algorithm” by Peter Fenwick Rate The University of Auckland, Department of Computer Science, Technical Report 120, July 1995.
“Block Sorting Text Compression — Final Report” by Peter Fenwick, Rate The University of Auckland, Department of Computer Science, Technical Report 130, April 1996.
The Sort Transformation by Michael Schindler Rate Michael Schindler’s page describing a sorting algorithm that was presented in a poster session at DCC ’97. Links to his source code, plus links to the paper and poster in postscript format. Update: Michael has made additional source code available.
“Experiments with a Block-Sorting Text Compression Algorithm” by Peter Fenwick Rate The University of Auckland, Department of Computer Science, Technical Report 111, March 1995.
An analysis of the second step algorithms in the Burrows-Wheeler compression algorithm Rate A paper by Sebastian Deorowicz. Implementing the BWT transform is nice and simple, but what you do with the transformed data is where all the action is. Traditionally, we use Move To Front followed by an entropy encoder. Sebastian talks about some alternatives that help compression.
Onet Attempt of a Compression Algorithm using BWT Rate by Bernhard Balkenhol and Yuri M. Shtarkov. Details tests of an improved version of the basic algorithm.
Text Preprocessing for Burrows-Wheeler Block Sorting Compression Rate A short paper discussing various preprocessing techniques that can be used in BWT-based compression programs. RTF format.
Asymptotic Optimality of the Block Sorting Data Compression Algorithm Rate Arimura shows that BWT is asymptotically optimal. Paper in PDF format.
Tree Source Identification with the Burrows Wheeler Transorm Rate by D. Baron and Y. Bresler. Postscript paper describing a technique that uses BWT to preprocess a sequence of symbols, then mung.
On variants of block-sorting compression using context from both the left and right Rate A technical note from Mike Burrows regarding a variation on block sorting.
A Second Modified Run Length Encoding Scheme for Blocksort Transformed Data Rate Another paper by Michael Maniscalo discussing a scheme for Run Length Encoding of data that’s been put through the blocksort transform. His first paper uses fixed length codes, this uses variable lenghts.
People

Burrows-Wheeler Transformation / Block Sorting (BWT) Jürgen Abel has done an enormous amount of research on the Burrows-Wheeler Transform, and has published the results on his web site. On this page you will find:
A summary of this compression technique.
Links to over 70 online papers.
Links to at least that many people involved in BWT research or development.
Extensive links to BWT source code.
This web page may now be the definitive source of information for this field.
Jürgen Abel Jürgen is the proprietor of www.data-compression.info, an excellent resource for developers and researchers. Jürgen has a good supply of links to papers, conferences, books, etc. on the site, as well as executables and source for ABC, a freeware BWT compressor he wote in Delphi.
Peter Fenwick. Rate
Dr. Peter Fenwick’s home page. Fenwick has links to several of his compression papers on this page, including several recent papers discussing BWT algorithms.
Giovanni Manzini Rate
Giovanni Manzini has published papers covering a few different topics in Data Compression, including several recent works on Burrows-Wheeler algorithms. He is currently an Associate Professor of Computer Science at the Universita degli Studi del Piemonte Orientale in the the most northern reaches of Italy.
Paolo Ferragina Rate
Paolo Ferragina’s research in data structures and string matching naturally lends itself to Data Compression and to the problem of indexing compressed data. See the link to his recent papers on indexing BWT compressed files. He is currently an Associate Professor of Computer Science at the University of Pisa.
Julian Seward Rate Julian Seward’s home page. Julian is the author of Bzip. This page appears to be slated for removal.
Source Code

Zzip – The New Compressor A new archiver that uses a BWT algorithm to achieve superior compression. The author has now released the source code to zzip under the GPL.
Burrows-Wheeler Transformation / Block Sorting (BWT) Jürgen Abel has done an enormous amount of research on the Burrows-Wheeler Transform, and has published the results on his web site. On this page you will find:
A summary of this compression technique.
Links to over 70 online papers.
Links to at least that many people involved in BWT research or development.
Extensive links to BWT source code.
This web page may now be the definitive source of information for this field.
ABC – Advanced Blocksorting Compressor ABC is a free data compression program based on the Burrows-Wheeler transformation. The source code is free for academic, research and educational use as depicted in the Abel Public License (APL). The program is developed in DELPHI as a command line program just like GZIP.
Update: Jürgen has released the source code for ABC at long last! The Delphi source is available for download from the web site and can be used under his own APL.
Data Compression with the Burrows-Wheeler Transform An article by Mark Nelson that appeared in the September 1996 issue of Dr. Dobb’s Journal. At the time it appeared, the BWT was relatively unknown among compression enthusiasts. This article includes source code that implements a simple test program that demonstrates BWT compression.
D.J. Wheeler’s FTP site Rate
Contains his implementation of the BWT algorithm, in the program bred. Along with this are some notes and papers on his implementation of BWT Current list of files: bexp.c bexp3.c bred.c bred.ps bred.ps.Z bred2 bred3.c bred3.ps exp.c huff.ps mintext.ps mintext.tex red.c tea.ps tub.ps wake.ps xtea.ps xxtea.ps
A Run Length Encoding Scheme For Block Sort Transformed Data Rate
A paper by Michael A. Maniscalco that desribes an RLE algorithm tailored for use with the BWT compression technique.
libbzip2 for WinCE Rate A version of libzip2 in source format for WinCE, along with demo code and project files. Ciprian Miclaus created this port along with one of zlib, and has made them available for all manking. Thanks Ciprian!
Embedded BWT Compression Rate Tom has posted his source code for embedded BWT compression. Basically, he’s trying to pull it off with low amounts of RAM.
The Sort Transformation by Michael Schindler Rate Michael Schindler’s page describing a sorting algorithm that was presented in a poster session at DCC ’97. Links to his source code, plus links to the paper and poster in postscript format. Update: Michael has made additional source code available.
Bzip2 classes Rate Gilad Novik created a pair of classes to compress and decompress data using the bzip2 format.
BWT in Matlab Rate Imran Akthar’s implementation of the BWT transform in Matlab. Free.
bwtzip: A Linear-Time Portable Research-Grade Universal Data Compressor Rate bwtzip is an ongoing project, distributed under the GNU General Public License, to implement a Burrows-Wheeler compressor in standard, portable C++. It is research-grade in that it is highly modularized and abstracted, so that it is simple to swap out parts of the compressor without affecting anything else. This makes it easy to experiment with different algorithms at different stages of compression.
Looks like Steven T. Lavavej released a new version of bwtzip in early February, 2003. A wide variety of improvements, most of them in implementation – not visible to the end user. A description of recent changes is found here
BWTCoder: Industrial strength BWT compression Rate This is a preliminary shot at creating an open source BWT compression engine. Things look very preliminary at this point with just a couple of files available for download and not much message traffic.
Embedded BWT Compression Rate An implementation of BWT designed with the goal of minimizing memory usage. Source code and a documentation page.
Karl Malbrain – BWT Source Rate Karl has created a complete BWT package, and has posted the source on this site. He also has an adaptation of N. Jesper Larsson’s Burrows-Wheeler Suffix Sorting for your perusal.
MacBzip2 Home Page Rate A port of Julan Seward’s bzip2 program to the Mac. It’s free and full source is included if you are the adventurous type.
bsdtar, libarchive Rate Libarchive is a programming library that can create and read several different streaming archive formats, including most popular tar variants and the POSIX cpio format. The bsdtar program is an implementation of tar(1) that is built on top of libarchive. It started as a test harness, but is quickly moving toward becoming a candidate system tar for FreeBSD
Tutorials, Reference, Presentations

Move to front The MTF algorithm is not very exciting, but it does a really nice job of compressing streams that have been put through the BWT transform. Arturo Campos gives an explanation of how to implement it in this paper.
BWT, a transformation algorithm Arturo Campos provides an easy-to-read explanation of the BWT transformation algorithm. This algorithm achieves very good compression ratios at relatively high speeds.
Data Compression with the Burrows-Wheeler Transform An article by Mark Nelson that appeared in the September 1996 issue of Dr. Dobb’s Journal. At the time it appeared, the BWT was relatively unknown among compression enthusiasts. This article includes source code that implements a simple test program that demonstrates BWT compression.
EGI compression schemes Rate
This page discusses the various compression schemes used by EGI, Shannon-Fano, BWT, and RLE. EGI is a player of animation sequences.
Sorting the matrix of two-sided contexts Rate
This article describes a variant on BWT that doesn’t use the cyclical rotations of strings used for BWT, but a different scheme. DCL reader points to a Burrows paper showing that this scheme is suboptimal.
Burrows-Wheeler Transformation Rate Helger Lipmaa created a BWT transformer in PHP, and can demo it to you right on the net at this page.
BWT Animation Rate The site bills itself as an animation, but in fact it is just a couple of screen captures that demonstrate an animation.
Full-Text Searching & the Burrows-Wheeler Transform Rate In this article, I examine an indexing method that lets you find any character sequence in the source text in time only proportional to the sequence length using a structure that can compress the entire source text and index into less space than the text alone. This technique is exceptionally fast at detecting and counting occurrences of any string in the source text.
bwtzip: A Linear-Time Portable Research-Grade Universal Data Compressor Rate bwtzip is an ongoing project, distributed under the GNU General Public License, to implement a Burrows-Wheeler compressor in standard, portable C++. It is research-grade in that it is highly modularized and abstracted, so that it is simple to swap out parts of the compressor without affecting anything else. This makes it easy to experiment with different algorithms at different stages of compression.
Looks like Steven T. Lavavej released a new version of bwtzip in early February, 2003. A wide variety of improvements, most of them in implementation – not visible to the end user. A description of recent changes is found here
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Coding

Coding refers to techniques used to encode tokens or symbols. Two of the best known coding algorithms are Huffman Coding and Arithmetic Coding. Coding algorithms are effective at compressing data when they use fewer bits for high probability symbols and more bits for low probability symbols.
[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Books

Source and Channel Coding: An Algorithmic Approach by John B. Anderson Rate
Source and Channel Coding: An Algorithmic Approach provides in-depth coverage of coded communication with the first unified treatment of trellis coding and modern bandwidth-efficient coding
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Source Coding Theory by Robert M. Gray Information Systems Laboratory, Stanford University, CA, USA Rate
Hardbound, ISBN 0-7923-9048-2 October 1989, 208 pp. Part of the Kluwer International Series in Engineering and Computer Science.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
French

Contributions à la compression de données Rate Steven Pigeon’s Ph. D Thesis from the University of Montreal. Proposes a new set of universal codes, which he dubs taboo codes, as well as new optimization algorithms for (Start, Step, Stop) codes. Plus lossy variations on LZW.
Links

Prefix Code Rate The definition from the NIST Dictionary of Algorithms and Data Structures.
Newsgroup Posts

The Kraft Inequality Rate A basic priniciple of coding.
Papers/Documentation

Multimedia Paper Summaries Rate A set of links to paper summaries, including a batch on Coding, Compression, and Media Formats.
Hirosuke Yamamoto’s Papers Rate This page has links to online versions of Hirosuke Yamamoto’s papers on data compression. Papers here on block sorting, coding, and more. The papers are all published in English.
Code Design via Selection of a Statistical Model Rate by John C. Kieffer (Information Theory Research Group, Electrical Engineering, University of Minnesota). A survey of techniques for designing codes with minimal redundancy. A Postscript copy of an academic paper.
Efficient stochastic source coding and an application to a Bayesian network source model Rate by Brendan J. Frey and Geoffrey E. Hinton. A new algorithm for generating efficient codes.
Contributions à la compression de données Rate Steven Pigeon’s Ph. D Thesis from the University of Montreal. Proposes a new set of universal codes, which he dubs taboo codes, as well as new optimization algorithms for (Start, Step, Stop) codes. Plus lossy variations on LZW.
Binary Encoding Rate A survey paper that covers the current roster of popular encoding algorithms, such as Base64, Base32, Hex, etc.
RF Coding Rate A paper by Eduardo Enrique González Rodriguez that describes a proposed new method of entropy encoding. Eduardo overcomes some of the problems faced by Huffman coding in certain circumstances, such as a very small alphabet.
Source Code

RF Coder Source Code Rate The source code to accompany Eduardo Enrique Gonzalez Rodriguez’s artice on RF coding, his proposed new entropy encoder. (Note that this archive contains his paper as well, so you don’t need to download both.)
Tutorials, Reference, Presentations

Data Compression – Static Defined-Word Schemes Rate
A very nice description of Huffman coding, as well as a few other types of coding. I believe this is part of a survey paper by Debra A. Lelewer and Daniel S. Hirschberg.
Cringely on Coding Rate Bob X. Cringely says that a new coding technique would give us a 10X bandwidth improvement on cable lines.
Location Based Encoding – LBE Rate Chitaranjan P.S., Arun Shankar, and Niyant .K posted a description of a new coding scheme called LBE on the web. It’s interesting, but I’m not sure that it appears to have any serious advantages over current state of the art.
Steven Pigeon’s Phasing In Codes Rate Coding integers of an arbitrary length is an interesting problem. Steven Pigeon discusses a way to code integers in a very efficient manner, which approaches the optimal Log2(n) value.
Prefix Code Rate The definition from the NIST Dictionary of Algorithms and Data Structures.
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Copyright © 2005 Visicron Corp. All rights reserved.
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Commercial Libraries

Libraries, DLLs, and OCXs that provide data compression services of some sort or another. The libraries listed in this section are either shareware or commercial, meaning they will almost always require payment if used in a product released to the general public. Many of the products offer trial versions that you can use for evaluation.
[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Archiving

DC Micro Home page for DC Micro, home of Crusher!, the data compression toolkit
Xceed Zip Compression Library A feature-rich COM/ActiveX and DLL component for adding Zip and Unzip to your Windows apps with minimum effort. Includes full documentation with many samples and examples for VB, VC++, Delphi and C++Builder to get you started quickly. Supports the latest zip file format updates including Deflate64 compression and Zip64 headers. Also includes BZip2 compression which is excellent for compressing XML data.
Xceed Zip for .NET A true native Microsoft.NET Zip file-handling and streaming compression class library. Its true object-oriented design makes manipulating zip files as easy as manipulating regular files and folders. Written entirely in managed C#, it includes a variety of VB.NET and C# samples and takes full advantage of the .NET runtime’s capabilities.
Abbrevia 3 by TurboPower Rate
A Delphi VCL that adds support for Zip and CAB files to your Delphi programs. From TurboPower.
ZipTV Rate
The ZipTV compression suite is a set of components to be used with Borland’s Delphi and C++ Builder products. Manage archives, SFXs, etc, with support for at least 15 archive formats.
Reader Joseph K. says Amazing collection of compression tools!.
DynaZIP-GT Rate
A set of Win32 libraries, DLLs, and controls that let you manipulate tar and gz format archives under Win32.
A DCL user had this to say: Worked very quickly, very reliable, absolutely worth the money, I had it running correctly in 5 minutes, mabye less. There was also more than enough sample code to work with. It’s the best G-zip compression library I have found anywhere..
Microsoft Cabinet Software Development Kit Rate
The Cabinet Software Development Kit provides developers with the components needed to utilize Microsoft’s cabinet file technology within other applications, or to build cabinet file management tools. Microsoft is committed to making cabinet files an open technology.
DCL User says: Easy implementation and works with memory mapped file too.
Delphi Skunkworks – Data Compression Rate A page full of links to data compression resources for Delphi Programmers. Mostly libraries.
Compression Plus 5.0 Rate EllTech makes a compression library that supports zip files, plus a bunch of other formats, including ARC, ARJ, tarballs, etc.
Update! EllTech’s products were acquired by BeCubed Software. Compression Plus 5.0 appears to still be available.
Audio

RareWares AAC Page Rate
A nice collection of AAC software, including encoders, decoders, and miscellaneous plugins.
RealNetworks Rate
Makers of lots of audio and video compression stuff.
Windows Media 9 Series Rate
Microsoft’s web page for all things releated to the new Windows Media Player and more. At this time you can download the beta version of the new player, get information, and sample various media.
Reader Serg N. commented: Very good quality, support for [very] low bitrates, lossless mode. It’s not open source, but it’s free!
Epigon Media Technologies Rate
It’s a little hard for me to tell what Epigon is selling. They have a nice picture of some kind of board on their front page, but I don’t think they have any hardware for sale. They do appear to have audio codecs for MPEG-1, MPEG-2, and MPEG-4, as well as what appears to be a proprietary speech codec called eSpeech.
Note: Reader Ragu says that despite the problem siwith the web page, he is a big fan of their products. He is a satisfied customer who feels their audio codecs are the best.
Windows Media 9 Downloads Rate
This page has links to the big batch of downloads that developers might need to work with Windows Media 9. At this time, the list of available packages includes:
Windows Media Format 9 Series SDK
Windows Media Player 9 Series SDK
Windows Media Encoder 9 Series SDK
Microsoft Windows Media Player for Pocket PC SDK
Windows Media Format 7 SDK for Macintosh
Windows Media Services SDK
Clipstream Audio Rate
Clipstream makes a java applet that gives web browsers the ability to play streaming audio without any special plugins or apps.
AVPhone ActiveX Controls Rate These ActiveX controls provide real-time compression and rendering of audio and video streams, supporting standard formats such as H.263, MPEG-4, G.723 and more. It appears that they are designed for IP Telephony, but they also advertise the ability to do straight-up compression to/from disk or memory. You can use a demo version for free, with limitations, but upgrading to the pro release is going to set you back a bit. Redistribution is included in the price, though.
Version 3.0 is shipping as of April, 2003.
Windows Media Video 9 Video Compression Manager Rate This tool lets you package content encoded with the Series 9 codecs in traditional AVI containers. Future applications should use the ASF file container, but legacy apps may be constrained to the AVI format. This tool allows the old and the new to work together.
This tool was shipping in a Beta version as of April, 2003.
Making Windows Media Player Plug-ins Work Together Rate An article on MSDN describing the plugin architecture of Windows Media Player 9.
Vibrant Communicator ActiveX Library Rate This ActiveX control is used by developers of audio applications to provide low-latency streaming compressed audio.
Arcsoft Mobile Media Codecs Rate Arcsoft has a line of mobile media codecs that includes support for MIDI, JPEG, PNG, GIF, and speech.
compaact! Rate compaact! allows you to easily encode your audio files with the high quality coding algorithm MPEG-4 AAC (Advanced Audio Coding). compaact! is capable of multichannel encoding and comes with extensive audio preprocessing features to achieve even better encoding results.
Version 1.2 is shipping in April, 2004.
Windows Media Player 9 Series Software Development Kit Rate The Microsoft® Windows Media® Player 9 Series Software Development Kit (SDK) provides information and tools to customize Windows Media Player and to use the Windows Media Player ActiveX® control. This documentation also provides information about using Windows Media metafiles.
Intel Integrated Performance Primitives Rate Intel has created a new library designed to deal with varous primitives used in Data Compression. Intel says: Intel® Integrated Performance Primitives (IPP) is a software library which provides a range of library functions for multimedia, audio codecs, video codecs (for example H.263, MPEG-4), image processing (JPEG), signal processing, speech compression (i.e. G.723, GSM ARM*) plus computer vision as well as math support routines for such processing capabilities.Unlike their previous libraries, this is now a commercial product which is going to cost you as much as $199. Works with Windows and Linux.
Windows Media 9 Series reviewed Rate This site collects information, links, and review on Windows Media 9. Includes some detailed information on the codecs that are part of the new package.
Asao Rate The Asao libraries from Nellysoft have been designed specifically to address the need for a very small footprint, low bandwidth speech and audio compression. Asao will operate at a variety of bit rates (12/16/24/32 Kbps). This new technology can be rapidly harnessed for applications such as streaming over mobile data networks, Internet radio and embedded platforms such as toys and other consumer devices.
DirectX 9.0 End-user Runtime Rate Microsoft has released DirectX 9.0, which naturally includes support for an updated list of audio and video encodings.
Windows Media 9 Final Release Rate This page has links to download all the various components of Windows Media 9, including the media player, codecs, encoders, embedded toolkits, and more.
Qdesign Rate The folks at Qdesign have a new audio encoding format they’d like you to use.
Backup

SuperCool ZIP Backup Rate SuperCool Zip Backup software is a data backup,restore and file synchronization program. You can use any drive in your system to store the backup files in standard Zip format that can be transferred to remote machine by FTP or Email. It can also compare and synchronize files or folders.
Version 1.61 is shipping as of May, 2003.
Burrows-Wheeler Transform/Block Sorting

Xceed Zip Compression Library A feature-rich COM/ActiveX and DLL component for adding Zip and Unzip to your Windows apps with minimum effort. Includes full documentation with many samples and examples for VB, VC++, Delphi and C++Builder to get you started quickly. Supports the latest zip file format updates including Deflate64 compression and Zip64 headers. Also includes BZip2 compression which is excellent for compressing XML data.
Xceed Streaming Compression Library The Xceed Streaming Compression Library is a high-performance “raw” compression library. It offers the ability to compress and decompress streaming data, buffers, strings or single files and supports multiple compressed data formats. Unlike the Xceed Zip Compression Library, this ultralight library doesn’t offer Zip file handling capabilities.
UPL Compression : the complete professional toolkit Rate
The UPL Compression Library is a high-performance professional compression library. It offers the ability to compress and decompress data, buffers, strings or single files and features the latest innovations in data compression. The library offers eight extremely powerful compression algorithms. Dynamic Huffman, Arithmetic, BWT, Ppm and several Lempel Ziv flavors.
DataCompression.info user John G. had this to say: I was looking for adding a better compression to my Visual Basic project and it worked like a charm. The compression ratio is really good, better than Zip!
Sax.net Streaming Compression Rate Sax.net Streaming Compression helps you keep your data small and fast. Use high-performance compression and data compression code, using a class library that was designed from the ground up for integration with the Microsoft .NET framework.
In addition to being able to specify whether to prefer speed over size, Sax.net Compression offers you a choice of two compression algorithms: Industry-standard Deflate (ZIP) compression, and the newer Burrows-Wheeler (BZip2) transform, which generates especially great results when compressing XML data.

Data Compression

Xceed Zip Compression Library A feature-rich COM/ActiveX and DLL component for adding Zip and Unzip to your Windows apps with minimum effort. Includes full documentation with many samples and examples for VB, VC++, Delphi and C++Builder to get you started quickly. Supports the latest zip file format updates including Deflate64 compression and Zip64 headers. Also includes BZip2 compression which is excellent for compressing XML data.
Xceed Zip for .NET A true native Microsoft.NET Zip file-handling and streaming compression class library. Its true object-oriented design makes manipulating zip files as easy as manipulating regular files and folders. Written entirely in managed C#, it includes a variety of VB.NET and C# samples and takes full advantage of the .NET runtime’s capabilities.
Xceed Streaming Compression Library The Xceed Streaming Compression Library is a high-performance “raw” compression library. It offers the ability to compress and decompress streaming data, buffers, strings or single files and supports multiple compressed data formats. Unlike the Xceed Zip Compression Library, this ultralight library doesn’t offer Zip file handling capabilities.
Programmer’s Heaven Compression Programs Rate
A really nice set of programs and source code for all sorts of data compression. This area doesn’t appear to be actively maintained, so there are plenty of out-of-date files, but good stuff mixed in as well.
Power SDK Rate Image Power makes a C++ SDK that performs both document and image compression. This supports JBIG2, MRC (Mixed Raster Content), and plugins for web browsers.
Delphi Skunkworks – Data Compression Rate A page full of links to data compression resources for Delphi Programmers. Mostly libraries.
LuraDocument Rate LuraDocument represents an innovative compression software custom-tailored to the compression of scanned color documents composed of both images and text. The documents are partitioned into pure picture and pure text segments through the use of its state-of-the-art segmentation algorithm. Each of these segments is then compressed using an algorithm optimized for this type of data. As a result, scanned color documents can be stored at extremely high quality despite small file sizes. LuraDocument is capable of reaching compression rates of 1:150 to 1:500 while still preserving full readability of the text and excellent quality of the pictures. This makes LuraDocument far superior to even the wide spread PDF format.
Esoterica/Miscellany

WSQ by Aware Rate
WSQ by Aware is our implementation of the Federal Bureau of Investigation’s Wavelet Scalar Quantization fingerprint compression standard. WSQ by Aware is the industry’s highest performing implementation of the FBI’s Wavelet Scalar Quantization (WSQ) digital fingerprint compression algorithm. WSQ is a wavelet transform-based compression standard, developed by the FBI for compression of digital fingerprint images.
ProGATE Rate Enbaya makes a product called ProGATE that is used to compress 3D graphics and animations for game developers.
GAO Research Modem Software Rate GAO Research sells modem software for quite a few different platforms, including a big batch of DSP parts. Naturally, this includes modules to perform both V.42bis and V.44 data compression.
GIF – Compuserve’s Graphics Interchange Format

Arcsoft Mobile Media Codecs Rate Arcsoft has a line of mobile media codecs that includes support for MIDI, JPEG, PNG, GIF, and speech.
Gzip

Xceed Streaming Compression for .NET Xceed Streaming Compression for .NET is an efficient and lightweight data compression class library for Microsoft .NET and ASP.NET. It can process any size byte array with ease and provides a true .NET pass-through stream object for automatically compressing or decompressing any .NET stream’s data on the fly. It supports the GZip, Zlib, Deflate and Deflate64 compression formats.
Xceed Zip for .NET Compact Framework Xceed Zip for .NET Compact Framework is a data compression and all-purpose file manipulation class library for creating mobile apps. It provides flexible zip, gzip and streaming data compression capabilities for compact applications created with Visual Studio .NET 2003. The library includes an innovative and extensible filesystem object model that makes zip files as easy to work with as regular files or folders.
IP*Works! Zip Component Suite Rate IP*Works! Zip allows developers to easily integrate compression and decompression functionality into web or desktop applications using popular file and data compression standards including Zip, Tar, Gzip and Jar standards for compression. All IP*Works! Zip components have been built from the ground up entirely in native .NET and Java code, combining exceptional speed, excellent data compression, and extreme portability across platforms.
The components feature password support, file deletion within an archive, streaming compression and decompression, and more. IP*Works! Zip is currently available as fully-managed 100% C# .NET components, or pure Java beans.
Huffman Coding

UPL Compression : the complete professional toolkit Rate
The UPL Compression Library is a high-performance professional compression library. It offers the ability to compress and decompress data, buffers, strings or single files and features the latest innovations in data compression. The library offers eight extremely powerful compression algorithms. Dynamic Huffman, Arithmetic, BWT, Ppm and several Lempel Ziv flavors.
DataCompression.info user John G. had this to say: I was looking for adding a better compression to my Visual Basic project and it worked like a charm. The compression ratio is really good, better than Zip!
Image Compression

RICAZip.com Rate
RICAZip.com has proprietary lossless image compression technology called RICA (Reversible Image Compression Algorithm). RICA retains original file formats (e.g. TIFF, DICOM, BMP, TGA, PGM etc.). RICACom says We have yet to find any method that provides better compression ratios (for truly lossless), including wavelet. On a PII 450MHz RICA compresses @ 6MB per second and decompresses at 12MB per second.
Available as a standalone image archive app, Adobe Photoshop Plugin, Browser Plugin, and RICA SDK.
DCL reader Karen H. says: Evaluation of this product demonstates excellent compression ratios and it is also very fast compared to other methods I have used.
BitJazz Rate
A company that makes PhotoJazz, a lossless compression plug in package that they describe as having Breakthrough lossless photo-quality compression of stills and movies for archival, print, and the Internet. Version 2.0 supports Mac and Windows, Photoshop, QuickTime, and Quark. You can download the Reader for free and try it out.
PDF Creator Pilot Rate This library is able to product PDF documents from VB, Delphi, and Visual C++. This naturally includes the ability to create compressed images using jpeg, zlib, and CCITT formats.
LuraWave OCX-SDK Rate The LuraWave OCX is an OLE-Control ready to be integrated into numerous development environments such as MS Visual C++, MS Visual Basic, Borland Delphi, and several of the MS Office components. This product allows you to easily load and decompress Lurawave images, as well as converting to/from TIFF and BMP formats. A demo version is available which limits you to 640×480 pixels.
ImageGear Rate ImageGear from Accusoft is a super-capable imaging library, available in four different varieties. It supports the normal roster of file types, but also includes some more advanced image and file formats, such as PDF and JPEG-2000.
Version 13 is shipping as of October, 2003.
The GSLib image compression library Rate Alexander Simakov has created a streaming, DCT-based, lossy compression library that works on gray scale images. This is a shareware library that works with Win32 programs. Registered users get source code, samples in several languages, and help files in English and Russian.
Intel Integrated Performance Primitives Rate Intel has created a new library designed to deal with varous primitives used in Data Compression. Intel says: Intel® Integrated Performance Primitives (IPP) is a software library which provides a range of library functions for multimedia, audio codecs, video codecs (for example H.263, MPEG-4), image processing (JPEG), signal processing, speech compression (i.e. G.723, GSM ARM*) plus computer vision as well as math support routines for such processing capabilities.Unlike their previous libraries, this is now a commercial product which is going to cost you as much as $199. Works with Windows and Linux.
ImagXpress Standard Rate This imaging library from PegasusImaging supports reading and writing of a wide variety of compressed image formats, including JPEG, GIF, and PNG. JPEG2000 and Lossless JPEG are advertised as available with add-on packages.
JBIG

Image Power Downloads Rate
Image Power has their products available for download here, which includes the commercial version of PowerCompressor, and a beta copy of Jasper, a JPEG2000 codec.
JPEG

Pegasus Medical Compression Toolkit Rate
Pegasus Imaging, a developer of high performance imaging software, today announced its new Medical Compression Toolkit product, a set of compression libraries intended to address specific needs in the medical imaging community. The Medical Compression Toolkit is a set of libraries for various image compression methods which have been adapted for medical use.
DCL reader reported: I used this tool for implementing Motion JPEG compression/decompression for 24-bit color, 800×600 medical images at frame rate of 30 on dual PIIIs. It is a good tool..
PICTools Imaging Library by Pegasus Imaging Rate
Pegasus Imaging Corporation, Tampa FL.announces the release today of new version of the PICTools imaging libraries for software developers.
PICTOOLS RAPIDVUE Rate The Fastest JPEG engine available! Pegasus high speed JPEG engine offering the fastest JPEG compression and decompression available based on algorithmic optimization, assembly level enhancements, Pentium II and Pentium III optimization.
Arcsoft Mobile Media Codecs Rate Arcsoft has a line of mobile media codecs that includes support for MIDI, JPEG, PNG, GIF, and speech.
JPEG-2000

Aware Inc. JPEG2000 Codec Rate
Aware makes a JPEG 2000 Codec and SDK, which includes libraries for both Win32 and UNIX. You can download a demo of their product from the web site should you be willing to provide a bit of contact data.
Kakadu Rate
The home page describes Kakadu thus: A comprehensive, heavily optimized, fully compliant software toolkit for JPEG2000 developers .
DataCompression.info user Tim A. gushed: A very fast implementation with a small memory footprint compared to Jasper and even other commercial implementations. Also handles large files better than all others I have tried. Very well done with motion JPEG2000, a viewer and a JPIP server to boot (and those are just the sample applications!). John J. added The best of any JPEG2000 compressors for lossless compression. Higher compression rates, and faster compression than Aware and Algo Vison Luratech.
TI releases DSP Developer Support for JPEG2000 Rate
Texas Instruments announced the release of a DSP based Image Developer’s Kit, with support coming for JPEG2000, MPEG-4, and other standards.
Image Power Downloads Rate
Image Power has their products available for download here, which includes the commercial version of PowerCompressor, and a beta copy of Jasper, a JPEG2000 codec.
LEAD JPEG2000 Plugin for Adobe Photoshop Rate
Read and write JPEG2000 files from Photoshop with this plugin.
DataCompression.info reader Eric was disappointed with this product: Their plugin’s preview mode does not work. Without it, the plugin is horribly crippled. .
Luratech Rate
Luratech has plugins and an SDK for both their proprietary format and JPEG2000. Products come in a dizzying array of options, ActiveX controls, C-SDK, Java-SDK, plugins for PhotoShop or browsers. Note that some of their products can now be downloaded as freeward!
Note: What was once LuraTech is now Algo Vision LuraTech.
Reader Tom H. says: Luratech is the fastest licensable SDK out there right now
PICTools JPEG2000 Rate
This is the PicTools JPEG2000 SDK, which lets you drop JPEG2000 compression and decompression into your C/C++ programs. Pegasus Imaging makes quite a few compression library products. In this particular case, it appears they enlisted the help of Algo Vision plc to develop this product.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
LEADTOOLS JPEG2000 Plugin Rate LEADTOOLS is now supporting JPEG2000 in their toolkits by means of this JPEG2000 plugin. Supports both file and stream formats, plus many additional features. Download of sample available.
THBJpeg2000 Rate This product is an addon to the THBImage Library. The Library is available as either a DLL or OCX, and supports a wide variety of image formats and operations. An 30-day evaluation version is available for download.
LHA

TCompLHA component set Rate A Delphi component. TCompLHA helps you create and manage archives compatible with the popular freeware LHArc and LHA utilities (these archives can also be processed by the popular WinZip program if you have LHA). Simple one-step methods such as Scan, Compress, Expand, Delete and Verify make archive management very easy. In addition it includes the TSegLHA component which allows for the creation of segmented (e.g. multi-disk) archives.
Lossless Compression

DC Micro Home page for DC Micro, home of Crusher!, the data compression toolkit
Xceed Streaming Compression Library The Xceed Streaming Compression Library is a high-performance “raw” compression library. It offers the ability to compress and decompress streaming data, buffers, strings or single files and supports multiple compressed data formats. Unlike the Xceed Zip Compression Library, this ultralight library doesn’t offer Zip file handling capabilities.
Xceed Streaming Compression for .NET Xceed Streaming Compression for .NET is an efficient and lightweight data compression class library for Microsoft .NET and ASP.NET. It can process any size byte array with ease and provides a true .NET pass-through stream object for automatically compressing or decompressing any .NET stream’s data on the fly. It supports the GZip, Zlib, Deflate and Deflate64 compression formats.
Xceed Zip for .NET Compact Framework Xceed Zip for .NET Compact Framework is a data compression and all-purpose file manipulation class library for creating mobile apps. It provides flexible zip, gzip and streaming data compression capabilities for compact applications created with Visual Studio .NET 2003. The library includes an innovative and extensible filesystem object model that makes zip files as easy to work with as regular files or folders.
Hi/fn, Inc. Rate
Hi/fn makes lossless compression hardware and software. They have a bunch of chips that implement LZS and MPCC compression, plus a library that does the same thing. I have been led to believe that these algorithms are partially or completely protected by patents.
RICAZip.com Rate
RICAZip.com has proprietary lossless image compression technology called RICA (Reversible Image Compression Algorithm). RICA retains original file formats (e.g. TIFF, DICOM, BMP, TGA, PGM etc.). RICACom says We have yet to find any method that provides better compression ratios (for truly lossless), including wavelet. On a PII 450MHz RICA compresses @ 6MB per second and decompresses at 12MB per second.
Available as a standalone image archive app, Adobe Photoshop Plugin, Browser Plugin, and RICA SDK.
DCL reader Karen H. says: Evaluation of this product demonstates excellent compression ratios and it is also very fast compared to other methods I have used.
BitJazz Rate
A company that makes PhotoJazz, a lossless compression plug in package that they describe as having Breakthrough lossless photo-quality compression of stills and movies for archival, print, and the Internet. Version 2.0 supports Mac and Windows, Photoshop, QuickTime, and Quark. You can download the Reader for free and try it out.
EasyCompression Library for Delphi Rate EasyCompression Library is a TFileStream, TMemoryStream and other TStream descendants replacement to their analogues with transparent compression/decompression and encryption in the same stream. All the methods, properties and behavior of TFileStream and TMemoryStream are supported, so it is very simple to replace them in the application code. Key features: Forward and backward seeks in compressed stream; Read and write any portion of data at any file position; OnProgress event handler and compression rate indicator; Password protection provided by Rijndael encryption algorithm; Fastest compression level is extremally fast.
PICVideo Codec from Pegasus Imaging Rate This software codec produces video in three different formats: Motion JPEG, Wavelet 2000, and Lossless JPEG.
Intelligent Compression Technologies Rate A company that speciailizes in providing compression technology to other companies.
HTMLZip Rate HTMLZip is a utility to creating compressed HTML pages. True compression algorithm reduces files to 20%-70% of original. JavaScript is used for extracting in your browser (no third-party software).
Release 1.06 appears to have gone out in October, 2002.
Master Creative Software Rate Supplier of data comrpession libraries to use with FoxPro. Includes FOXSQZ, an archiving and compression library, COMP5, a compression library, and JavaSQZ, a data compression library for Java.
LZ77/LZSS and derivatives

PKWare Data Compression Library Format Rate
In this comp.compression posting, Ben Rudia-Gould opens up the compression format used by the PKWare Data Compression Library. This is the only place I have ever seen this information disclosed; PKWare has certainly not done so.
LZSLib – a windows compression .DLL for windows programmers. Rate
LZSSLib is a compression library (DLL) for Windows programmers. You have access to compression/decompression functions permitting file-to-file operations. LZSSLib uses the LZSS algorithm with various modifications each providing different enhancements. Very simple to use: LZSSPackFile(‘PROG.EXE’, ‘PROG.LZS’) Works with any language that supports DLL calling, such as Turbo Pascal, C/C++, Actor, Visual Basic, Realizer, even ObjectVision.
UPL Compression : the complete professional toolkit Rate
The UPL Compression Library is a high-performance professional compression library. It offers the ability to compress and decompress data, buffers, strings or single files and features the latest innovations in data compression. The library offers eight extremely powerful compression algorithms. Dynamic Huffman, Arithmetic, BWT, Ppm and several Lempel Ziv flavors.
DataCompression.info user John G. had this to say: I was looking for adding a better compression to my Visual Basic project and it worked like a charm. The compression ratio is really good, better than Zip!
TCompress Component Set Rate
File and database compression components for Delphi. Compress to/from file, memory, and blob. Uses RLE, LZH, and LZW. Shareware.
Version 7.0 was released in September of 2002.
Free DCL Decompressor Rate Mark Adler built a decompressor that is able to read streams built with PKWare’s Data Compression Library. Since PKWare hasn’t released source for DCL, this is a very good thing, and free to boot.
More PKWare DCL Decompression Code Rate C++ code posted to comp.compression that describes extraction from PKWare’s Data Compression Library.
Update: The author posted this correction to comp.compression: There’s a bug in the code posted 2001-10-07 19:36:38 PST. To fix: In the
void tcDecoder::Decode(char *apBuffer, unsigned int *apSize, unsigned int anBufferSize)
function after both
if (lnIndex == mnCurrentPos) lnIndex = lnStartIndex;
add
if (lnIndex == mnDictionarySize) lnIndex = 0;
DCompress v1.00 library Rate For Delphi and other Windows compilers. Compression/ Decompression routines .DLL library. Mostly assembler, Fast decompression!
LZ78/LZW and derivatives

Java PDF Libraries Rate
A variety of libraries that can be used to read and write PDF format.
TCompress Component Set Rate
File and database compression components for Delphi. Compress to/from file, memory, and blob. Uses RLE, LZH, and LZW. Shareware.
Version 7.0 was released in September of 2002.
GAO Research Modem Software Rate GAO Research sells modem software for quite a few different platforms, including a big batch of DSP parts. Naturally, this includes modules to perform both V.42bis and V.44 data compression.
MP3/MPEG Audio

Epigon Media Technologies Rate
It’s a little hard for me to tell what Epigon is selling. They have a nice picture of some kind of board on their front page, but I don’t think they have any hardware for sale. They do appear to have audio codecs for MPEG-1, MPEG-2, and MPEG-4, as well as what appears to be a proprietary speech codec called eSpeech.
Note: Reader Ragu says that despite the problem siwith the web page, he is a big fan of their products. He is a satisfied customer who feels their audio codecs are the best.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
MPEG

Elecard Rate
This company has a roster of compression products, including an MPEG-2 Player, an MPEG-2 DirectShow Filter, and a Wavelet Image Compressor.
DataCompression.info user Kuka had this to say: Excellent mpeg player, and a lot of very useful mpeg tools.
RareWares AAC Page Rate
A nice collection of AAC software, including encoders, decoders, and miscellaneous plugins.
TI releases DSP Developer Support for JPEG2000 Rate
Texas Instruments announced the release of a DSP based Image Developer’s Kit, with support coming for JPEG2000, MPEG-4, and other standards.
UB Video, Inc. Rate
UB Video says: UB Video Inc., based in Vancouver, Canada, is a leading provider of coding and transcoding software solutions for video communications. UB Video provides software products that run on desktop PCs as well as on programmable Digital Signal Processors and Media Processors. UB Video’s products include:
Encoders/Decoders
H.261 (Libraries/Source code)
H.263/H.263+ (Libraries/Source code, Encoder/Decoder DirectShow filters, Video for Windows codecs, Java decoder)
MPEG-4 (Libraries/Source code)
MPEG-2 (Libraries/Source code) Transcoders
H.263 to H.261 and H.261 to H.263 (Libraries)
MPEG-2 to MPEG-4 (Libraries) Free demos of the H.263+ codec (UB-Live) and MPEG-4 codec (UB-Stream) can be downloaded from the web site.
PixelTools – the MPEG Experts Rate
MPEG encoders and decoders, authoring software, and libraries.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
MPEGPas Rate A commercial MPEG video compression library written completely in Pascal (Borland Delphi, source code included). A demo version and the documentation can be downloaded.
MainConcept H.264 codec Rate MainConcept is proud to announce the immediate availability of our H.264 Encoder Preview Version for Microsoft® Windows®! Although not yet optimized for speed, this free demo will enable you to sample the quality of our newest codec. H.264 AVC (Advanced Video Coding), also known as MPEG-4 Part 10, is an exciting new standard which offers many advantages and has the potential to replace existing standards.
MainConcept H.264 SDK Rate This SDK decodes and encodes H.264 AVC (Advanced Video Coding) frames, making it easy to add support for this exciting new format to your applications. The MainConcept H.264 Codec will offer ultra-high quality encoding to and decoding from H.264 material at exceptional speeds in all profiles and levels supported by the standard.
PsyTEL Research Rate PsyTEL Research sells a high-quality MPEG-2 and MPEG-4 AAC audio coding library. Free demo (unlimited) is available for download. AAC library is optimized for speed (support for MMX, Pentium II, Pentium III and Pentium IV) and quality (providing AAC quality), supports VBR (variable bitrate coding), etc..
MPEG-4 encoding on a cell phone? Rate This article describes a proof-of-concept app running on a Nokia 7650 that performs MPEG-4 encoding and decoding, creating a portable video phone. No word on how you can get the code, or how difficult it would be to port this Symbios OS product to other platforms. Still, the company that developed the product, Hantro Products, does supply the codecs that do the trick.
DirectX VA Rate Microsoft is providing a Microsoft® DirectX® application programming interface (API) and a corresponding device driver interface (DDI) for acceleration of video codec processing. This API/DDI provides an interface definition focused on support of MPEG-2 “main profile” video (formally ITU-T H.262 | ISO/IEC 13818-2), but also intended to support other key video codecs (ITU-T Recommendations H.263 and H.261, and MPEG-1 and MPEG-4). The interface is designed to extract the most basic computationally-intensive building-blocks of these various codec designs and support their acceleration in hardware.
DivX Rate This is the current home for the DivX encoder and decoder. DivX ships in three different versions which offer varying levels of features for varying prices (including free.) Shipping DivX Video 5.1.1 as of November, 2003.
DivX for Gamecube SDK Rate If you’re a Gamecube developer, you’ve got to like the idea of incorporating DivX video sequences in your games. The great compression levels you can achieve with the MPEG-4 encoding lets you bring an incredible amount of video to this console.
PNG

Toolkits and Programming Libraries with PNG Support Rate
Toolkits and Programming Libraries with PNG Support
Arcsoft Mobile Media Codecs Rate Arcsoft has a line of mobile media codecs that includes support for MIDI, JPEG, PNG, GIF, and speech.
PPM

UPL Compression : the complete professional toolkit Rate
The UPL Compression Library is a high-performance professional compression library. It offers the ability to compress and decompress data, buffers, strings or single files and features the latest innovations in data compression. The library offers eight extremely powerful compression algorithms. Dynamic Huffman, Arithmetic, BWT, Ppm and several Lempel Ziv flavors.
DataCompression.info user John G. had this to say: I was looking for adding a better compression to my Visual Basic project and it worked like a charm. The compression ratio is really good, better than Zip!
Run Length Encoding/RLE

TCompress Component Set Rate
File and database compression components for Delphi. Compress to/from file, memory, and blob. Uses RLE, LZH, and LZW. Shareware.
Version 7.0 was released in September of 2002.
Self Extractors/Executable Packers

ZipTV Rate
The ZipTV compression suite is a set of components to be used with Borland’s Delphi and C++ Builder products. Manage archives, SFXs, etc, with support for at least 15 archive formats.
Reader Joseph K. says Amazing collection of compression tools!.
Speech

VoiceAge Corporation Rate
Our technology served as the foundation for numerous voice compression products used by voice portal and large multinationals in their efforts to better meet the quality requirements that end users. As example voice email, voice chatting, voice annotation in web site. Our technology is already integrated into software by companies such as Microsoft with its Netshow® software and in its Mediaplayer®, and RealNetworks within its RealAudio® and RealVideo®. In addition, over the last decade this compression technology (over 100 patents) was positioned in several International Telecommunication standards, notably: GSM ,PCS, TDMA ,CDMA, TETRA, G.729 . VoiceAge’s compression technology is well positioned at cross road of internet and voice for next-generation of voice portal.
Voice Recording Applet SDK Rate
The voice recording applet SDK is designed for the web developers and allows to record the voice from web site, to compress it and to send to the web server via HTTP. To playback the recorded voice from the server the embedded voice streaming player or a separate player as a voice streaming applet can be used. Both applets are designed in Java 1.1 and has a JavaScript interface.
ComPacketer Rate
The folks at Compandent have this to say about their product: Compandent’s ComPacketer is a voice coder which achieves a breakthrough in quality/bit rate/complexity tradeoff. Compandent’s novel technology, the ComPacketer that operates at 2.8 kb/s, produces speech with quality which exceeds that of ITU-T G.723.1 at 6.3 kb/s. Using the ComPacketer, only graceful degradation is introduced in frame erasure environment, as compared to the higher quality degradation introduces by the common standards used for VoIP.
Sipro Lab Telecom Rate
These folks make several different G.729 and G.723.1 codecs,
Sase Rate
The Sase libraries fron Nellysoft offer flexible compression options for both embedded and data packets based compression implementations It can operate in either a single bit rate or a multi-rate mode, offering compression rates (1.8/3.2/6.4 Kbps) to suit your application or the changing environment of packet based networks. Sase has the ability to switch bit rates on-the-fly to better handle changing network condition. At 3.2 Kbps Sase offers near toll quality, as you would expect when more bits are added the speech quality improves at 6.4 Kbps.
Epigon Media Technologies Rate
It’s a little hard for me to tell what Epigon is selling. They have a nice picture of some kind of board on their front page, but I don’t think they have any hardware for sale. They do appear to have audio codecs for MPEG-1, MPEG-2, and MPEG-4, as well as what appears to be a proprietary speech codec called eSpeech.
Note: Reader Ragu says that despite the problem siwith the web page, he is a big fan of their products. He is a satisfied customer who feels their audio codecs are the best.
Digital Voice Systems Inc. Rate
This company makes the AMBE-2000, a Vocoder chip that compresses speech down to a miniscule 4 Kbps. They have an additional product library of low bit-rate codes both in hardware and software.
TrueSpeech Rate
The DSP Group makes a codec called TrueSpeech. You can get a copy of the player for free here to check out the 8.5 KBps audio it makes possible.
Spirit Corp Rate Spirit has a wide variety of speech codecs for sale, including standard G.711, G.729 and so on, all the way down to proprietary 1200 bps coders.
EasyAudio Rate The EasyAudio ActiveX Control adds speech handling capabilities to your Win32 program. Listed features include nice things such as support for popular codecs including G.729, G.711, and ADPCM, unicast and multicast support, AGC, jitter buffer management, and noise reduction. The web page gives a price of $1000 for the control, and $2000 for the source code. I hope that big price tag includes free distribution rights, but the web site is woefully short on license information. Version 3.0 is shipping as of March, 2003.
GAO Research Speech Codec Software Rate GAO Research sells speech codecs for quite a few different platforms, including a big batch of DSP parts. They support a wide varity of ITU formats, including G.729, G.711, G.722, and more.
Hawk Software Commercial Speech Codecs Rate Hawk Software is now selling a pair of codecs, LPC-10 and OpenLPC, that are suitable for Windows CE, CELinux, and other 32-bit embedded platforms. More are planned for future releases.
Intel Integrated Performance Primitives Rate Intel has created a new library designed to deal with varous primitives used in Data Compression. Intel says: Intel® Integrated Performance Primitives (IPP) is a software library which provides a range of library functions for multimedia, audio codecs, video codecs (for example H.263, MPEG-4), image processing (JPEG), signal processing, speech compression (i.e. G.723, GSM ARM*) plus computer vision as well as math support routines for such processing capabilities.Unlike their previous libraries, this is now a commercial product which is going to cost you as much as $199. Works with Windows and Linux.
Asao Rate The Asao libraries from Nellysoft have been designed specifically to address the need for a very small footprint, low bandwidth speech and audio compression. Asao will operate at a variety of bit rates (12/16/24/32 Kbps). This new technology can be rapidly harnessed for applications such as streaming over mobile data networks, Internet radio and embedded platforms such as toys and other consumer devices.
Video

Essential Viewing Rate
Our technology set is based on the Essential Video 4.0 codec, which is a flexible and dynamic codec which utilises a number of video compression techniques using our BestFirst algorithm; methods include vector quantisation, motion compensation and residual encoding.
Morgan M-JPEG2000 codec V1 Rate
This is the download page for the Morgan Motion JPEG2000 codec. You can download a free copy of the codec and check it out. Support included for Video For Windows/DirectShow, and some video clips in AVI format are included.
RealNetworks Rate
Makers of lots of audio and video compression stuff.
Windows Media 9 Series Rate
Microsoft’s web page for all things releated to the new Windows Media Player and more. At this time you can download the beta version of the new player, get information, and sample various media.
Reader Serg N. commented: Very good quality, support for [very] low bitrates, lossless mode. It’s not open source, but it’s free!
UB Video, Inc. Rate
UB Video says: UB Video Inc., based in Vancouver, Canada, is a leading provider of coding and transcoding software solutions for video communications. UB Video provides software products that run on desktop PCs as well as on programmable Digital Signal Processors and Media Processors. UB Video’s products include:
Encoders/Decoders
H.261 (Libraries/Source code)
H.263/H.263+ (Libraries/Source code, Encoder/Decoder DirectShow filters, Video for Windows codecs, Java decoder)
MPEG-4 (Libraries/Source code)
MPEG-2 (Libraries/Source code) Transcoders
H.263 to H.261 and H.261 to H.263 (Libraries)
MPEG-2 to MPEG-4 (Libraries) Free demos of the H.263+ codec (UB-Live) and MPEG-4 codec (UB-Stream) can be downloaded from the web site.
H.263/H.263+ Research Library, Release 0.2 Rate
The package consists of the following modules:
H.263/H.263+ codec, C source code
Input and Output Modules, C source code
Configuration file parser/interpreter, C source code
Graphical User Interface, MS-Windows object code only
Support tools, C source code
All necessary header and resource files
Makefiles and Project files for UNIX and MS Developer Studio
Executables for MS-Windows

DCL User comment:Not as easy to download from this site as it once was. Software they are selling has a few bugs.
The On2 VP6 Video Codec Rate
The folks at On2 have a pretty nice sounding video codec here, designed for computer applications and set-top boxes. Looks like they want to go head-to-head with Windows Media 9 and MPEG-4.
Windows Media 9 Downloads Rate
This page has links to the big batch of downloads that developers might need to work with Windows Media 9. At this time, the list of available packages includes:
Windows Media Format 9 Series SDK
Windows Media Player 9 Series SDK
Windows Media Encoder 9 Series SDK
Microsoft Windows Media Player for Pocket PC SDK
Windows Media Format 7 SDK for Macintosh
Windows Media Services SDK
Video Clipstream Rate Clipstream has a java applet that enables streaming video in most web browsers with no additional plugins or downloads.
Microsoft Seeks to Depose MPEG-2 Rate EETimes reports on Microsoft’s Corona encoder – a video encoder that is touted as being superior to MPEG-2. The movie business is in a quandry, faced with the technical demands needed to put HD movies on disk. Using conventional compression, they would need to convert to costly blue-laser driven systems. Microsoft offers them a way to put more data on existing disks with just firmware upgrades.
PICVideo Codec from Pegasus Imaging Rate This software codec produces video in three different formats: Motion JPEG, Wavelet 2000, and Lossless JPEG.
ProGATE Rate Enbaya makes a product called ProGATE that is used to compress 3D graphics and animations for game developers.
Easy Video Rate The EasyVideo ActiveX control lets you integrate real-time video into any Win32 app that can host an ActiveX control. Video features supported include video capture, transmission, compression, and decompression, using standard Windows codecs as well as MPEG-4. Additional niceties include multicast support and bandwidth adjustment.
Version 3.0 is shipping in March, 2003.
AVPhone ActiveX Controls Rate These ActiveX controls provide real-time compression and rendering of audio and video streams, supporting standard formats such as H.263, MPEG-4, G.723 and more. It appears that they are designed for IP Telephony, but they also advertise the ability to do straight-up compression to/from disk or memory. You can use a demo version for free, with limitations, but upgrading to the pro release is going to set you back a bit. Redistribution is included in the price, though.
Version 3.0 is shipping as of April, 2003.
Windows Media Video 9 Video Compression Manager Rate This tool lets you package content encoded with the Series 9 codecs in traditional AVI containers. Future applications should use the ASF file container, but legacy apps may be constrained to the AVI format. This tool allows the old and the new to work together.
This tool was shipping in a Beta version as of April, 2003.
Making Windows Media Player Plug-ins Work Together Rate An article on MSDN describing the plugin architecture of Windows Media Player 9.
SheerVideo Rate SheerVideo is a QuickTime video codec. Looks like they currently only support the Mac platform, but Linux and Windows support is promised soon.
Windows Media Player 9 Series Software Development Kit Rate The Microsoft® Windows Media® Player 9 Series Software Development Kit (SDK) provides information and tools to customize Windows Media Player and to use the Windows Media Player ActiveX® control. This documentation also provides information about using Windows Media metafiles.
4i2i Communications Systems Rate These folks make H.261 and H.263 codecs for applications that need video compression. They have source and object software for the PC, as well as IP versions of their hardware design. The web site is reputed to have demo versions of some of their software.
RAD Game Tools Rate Makers of Blink and Smacker, a pair of Video codecs targeted towards game developers. These products appear to be carefully targeted towards the perfomance needs of PC-based games.
Intel Integrated Performance Primitives Rate Intel has created a new library designed to deal with varous primitives used in Data Compression. Intel says: Intel® Integrated Performance Primitives (IPP) is a software library which provides a range of library functions for multimedia, audio codecs, video codecs (for example H.263, MPEG-4), image processing (JPEG), signal processing, speech compression (i.e. G.723, GSM ARM*) plus computer vision as well as math support routines for such processing capabilities.Unlike their previous libraries, this is now a commercial product which is going to cost you as much as $199. Works with Windows and Linux.
Windows Media 9 Series reviewed Rate This site collects information, links, and review on Windows Media 9. Includes some detailed information on the codecs that are part of the new package.
Motion Wavelets Video Rate MotionWavelets is a software video codec that delivers real-time, high-quality video compression to the PC-based digital video user. Powered by a wavelet-based compression engine optimized for MMX processors, MotionWavelets compresses 640×480, 30 frames per second video with VHS quality, in real time on a PII/450MHz PC. MotionWavelets will compress greater than 60 fps 320×240 on any P/MMX 200MHz PC or above. MotionWavelets is available as a Video for Windows (VfW) installable codec and a Software Development Kit (SDK).
DirectX 9.0 End-user Runtime Rate Microsoft has released DirectX 9.0, which naturally includes support for an updated list of audio and video encodings.
Windows Media 9 Final Release Rate This page has links to download all the various components of Windows Media 9, including the media player, codecs, encoders, embedded toolkits, and more.
Wavelets

Essential Viewing Rate
Our technology set is based on the Essential Video 4.0 codec, which is a flexible and dynamic codec which utilises a number of video compression techniques using our BestFirst algorithm; methods include vector quantisation, motion compensation and residual encoding.
Elecard Rate
This company has a roster of compression products, including an MPEG-2 Player, an MPEG-2 DirectShow Filter, and a Wavelet Image Compressor.
DataCompression.info user Kuka had this to say: Excellent mpeg player, and a lot of very useful mpeg tools.
WSQ by Aware Rate
WSQ by Aware is our implementation of the Federal Bureau of Investigation’s Wavelet Scalar Quantization fingerprint compression standard. WSQ by Aware is the industry’s highest performing implementation of the FBI’s Wavelet Scalar Quantization (WSQ) digital fingerprint compression algorithm. WSQ is a wavelet transform-based compression standard, developed by the FBI for compression of digital fingerprint images.
Luratech Rate
Luratech has plugins and an SDK for both their proprietary format and JPEG2000. Products come in a dizzying array of options, ActiveX controls, C-SDK, Java-SDK, plugins for PhotoShop or browsers. Note that some of their products can now be downloaded as freeward!
Note: What was once LuraTech is now Algo Vision LuraTech.
Reader Tom H. says: Luratech is the fastest licensable SDK out there right now
Pegasus Medical Compression Toolkit Rate
Pegasus Imaging, a developer of high performance imaging software, today announced its new Medical Compression Toolkit product, a set of compression libraries intended to address specific needs in the medical imaging community. The Medical Compression Toolkit is a set of libraries for various image compression methods which have been adapted for medical use.
DCL reader reported: I used this tool for implementing Motion JPEG compression/decompression for 24-bit color, 800×600 medical images at frame rate of 30 on dual PIIIs. It is a good tool..
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
Wavelet Image Software Developer’s Kit Rate Summus makes an SDK that creates compressed files in a proprietary format. They give away a plugin that can be used to view the compressed files in the normally-supported browsers.
Motion Wavelets Video Rate MotionWavelets is a software video codec that delivers real-time, high-quality video compression to the PC-based digital video user. Powered by a wavelet-based compression engine optimized for MMX processors, MotionWavelets compresses 640×480, 30 frames per second video with VHS quality, in real time on a PII/450MHz PC. MotionWavelets will compress greater than 60 fps 320×240 on any P/MMX 200MHz PC or above. MotionWavelets is available as a Video for Windows (VfW) installable codec and a Software Development Kit (SDK).
Zip

Xceed Zip Self-Extractor Module This is an optional add-on for the Xceed Zip Compression Library ActiveX/DLL that lets your applications create sharp-looking self-extracting Zip files (.EXE’s) about as powerful as some install programs.
DC Micro Home page for DC Micro, home of Crusher!, the data compression toolkit
Xceed Zip Compression Library A feature-rich COM/ActiveX and DLL component for adding Zip and Unzip to your Windows apps with minimum effort. Includes full documentation with many samples and examples for VB, VC++, Delphi and C++Builder to get you started quickly. Supports the latest zip file format updates including Deflate64 compression and Zip64 headers. Also includes BZip2 compression which is excellent for compressing XML data.
Xceed Zip for .NET A true native Microsoft.NET Zip file-handling and streaming compression class library. Its true object-oriented design makes manipulating zip files as easy as manipulating regular files and folders. Written entirely in managed C#, it includes a variety of VB.NET and C# samples and takes full advantage of the .NET runtime’s capabilities.
Xceed Streaming Compression for .NET Xceed Streaming Compression for .NET is an efficient and lightweight data compression class library for Microsoft .NET and ASP.NET. It can process any size byte array with ease and provides a true .NET pass-through stream object for automatically compressing or decompressing any .NET stream’s data on the fly. It supports the GZip, Zlib, Deflate and Deflate64 compression formats.
Xceed Zip for .NET Compact Framework Xceed Zip for .NET Compact Framework is a data compression and all-purpose file manipulation class library for creating mobile apps. It provides flexible zip, gzip and streaming data compression capabilities for compact applications created with Visual Studio .NET 2003. The library includes an innovative and extensible filesystem object model that makes zip files as easy to work with as regular files or folders.
LSZip2 Data Compression Toolkit Rate
A Zip compatible library with a very impressive set of claims. Works with dozens of programming languages, offers full support for PKZip archives from 1.10 on, and more. Free evaluation version available.
Reader Carl P. says This is a must have tool.
Polar Zip 5.0 Rate
Polar Zip is a Win32 component that provides all the compression and archiving features you could ever need. Use with any development environment that can accept an ActiveX control.
Polar has added a .NET version of their Zip component in May, 2003.
Abale Zip ActiveX Control 5.0 Rate
Abale Zip is a royalty-free, robust and powerful Zip and Unzip component that costs much less than you would expect. It includes all the compression functionality you need in one easy to use ActiveX DLL that you distribute with your applications. The component works perfectly with VB, Delphi, ASP, C++Builder and Visual C++ and offers tons of sample applications to get you started. Looks like you can D/L a trial version, not clear from the web site if it’s crippled in any way. The web site works hard to explain that their component costs half of what you’ll pay for Xceedsoft’s product.
BigSpeed Zip DLL Rate
A complete Zip compression library for Win32 programmers in a 50K DLL.
Version 3.02 of this DLL shipped in May of 2002.
Inner Media, Inc. Rate
Innermedia makes DynaZip, a Zip compatible library.
addZIP Compression Libraries Rate
The home page for addZip, a shareware Zip library. Libraries and controls available for 16 and 32 bit versions of MS-DOS and Windows, with support for various compilers. This is a commercial product, but an evaluation version of the library is available.
One DataCompression.info user complained that the support from the supplier is poor. Another offered this comment: The software is good. Lacks some minor things which the supplier promised he will upgrade, but never replied to my mails. Apart from the support, the software is quite good..
DynaZIP ZIP/UNZIP toolkits Rate
DynaZIP offers just about everything you’d want to work with Zip files in a Win32 environment.
DataCompression.info user Mike L. had this to say: Creates huge output executables. Features contained in multiple packages are contained in a single package in comparable products. Pricing is very steep compared to comparable products.
BigSpeed Zip DLL 3.0 Rate Lets you add zipping and unzipping capabilities to any application. The ZIP engine is written in fast, highly-optimized assembler code, so it can perform at speeds up to 2 times faster than other ZIP libraries. The API is simple to use and can be called from any programming language that supports DLLs. Examples are included that illustrate how to use the DLL with Delphi, Visual C++, Visual Basic, and Visual FoxPro. Shareware
addZIP Compression Libraries v0.6 (DLL) Rate The complete compression solution for Windows developers. PKZIP-compatible file compression libraries (disk spanning, encryption etc). Memory compression library. Compatible with C/C++, Delphi and Visual Basic as well as most other development applications. Shareware.
Chilkat Zip Rate Chilkat Zip is an easy-to-use, royalty-free ActiveX control that empowers your applications to create/manipulate Zip archives. It can encrypt your data with the latest 256-bit AES Encryption, includes self-extracting EXE capabilities, and provides easy access to decompressed contents of individual files stored within a Zip archive. You can easily compress directly from memory buffers or strings and add multiple files with wildcarding and recursing directories.
IP*Works! Zip Component Suite Rate IP*Works! Zip allows developers to easily integrate compression and decompression functionality into web or desktop applications using popular file and data compression standards including Zip, Tar, Gzip and Jar standards for compression. All IP*Works! Zip components have been built from the ground up entirely in native .NET and Java code, combining exceptional speed, excellent data compression, and extreme portability across platforms.
The components feature password support, file deletion within an archive, streaming compression and decompression, and more. IP*Works! Zip is currently available as fully-managed 100% C# .NET components, or pure Java beans.
PKWARE Developer Solutions Rate PKWare has created a couple of new SDKs that allow developers to create and manipulate ZIP files, as well as to take advantage of PKWares new security features.
Sax.net Streaming Compression Rate Sax.net Streaming Compression helps you keep your data small and fast. Use high-performance compression and data compression code, using a class library that was designed from the ground up for integration with the Microsoft .NET framework.
In addition to being able to specify whether to prefer speed over size, Sax.net Compression offers you a choice of two compression algorithms: Industry-standard Deflate (ZIP) compression, and the newer Burrows-Wheeler (BZip2) transform, which generates especially great results when compressing XML data.

BigSpeed Zip OCX Rate BigSpeed Zip OCX is a multi-threaded, fully self-contained ActiveX control, which lets you add zipping and unzipping capabilities to any 32-bit Windows application.
Version 2.1.0.26 of this library shipped in March of 2001.
zlib

Xceed Streaming Compression Library The Xceed Streaming Compression Library is a high-performance “raw” compression library. It offers the ability to compress and decompress streaming data, buffers, strings or single files and supports multiple compressed data formats. Unlike the Xceed Zip Compression Library, this ultralight library doesn’t offer Zip file handling capabilities.
Xceed Streaming Compression for .NET Xceed Streaming Compression for .NET is an efficient and lightweight data compression class library for Microsoft .NET and ASP.NET. It can process any size byte array with ease and provides a true .NET pass-through stream object for automatically compressing or decompressing any .NET stream’s data on the fly. It supports the GZip, Zlib, Deflate and Deflate64 compression formats.
Xceed Zip for .NET Compact Framework Xceed Zip for .NET Compact Framework is a data compression and all-purpose file manipulation class library for creating mobile apps. It provides flexible zip, gzip and streaming data compression capabilities for compact applications created with Visual Studio .NET 2003. The library includes an innovative and extensible filesystem object model that makes zip files as easy to work with as regular files or folders.
Maquisistem Zlib StringCompress OCX Rate An OCX for compressing and decompressing strings and files. Sample program for VB5 included.
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Commercial Programs

Commercial Programs. In general, this includes both shareware and conventional retail programs. Stuff you have to pay for to use. There is obviously some blurring of the lines, (for example some shareware is free for individual use), but when there is doubt, I usually err towards classifying a product as commercial.
Archiving

Xtractor Plus Home of Xtractor Plus, handy multiple archive extraction utility for Zip, Rar, Ace, and Arj type archives.
Absolute Packager from Xceed Software Inc Easily create sharp-looking, feature-rich Self-Extracting (.EXE) Zip files with this handy desktop application. Lets you quickly select a group of files to zip up and put into a .EXE file. Even supports being able to split the .EXEs across multiple floppy disks.
BraZip 4.0 Rate
Another archiver that supports the zip format? Yep, that’s what it is.Of course, BraZip does support TAR, RAR, GZ, LHA, and a host of other formats. Cruise around the web site a bit and you’ll find the same information in Portuguese.
WinHki Rate
WinHki is an archiving tool that understands the usual gamut of formats – compresses 9, decompresses 12, and one of this is its own proprietary HKI format.
Self-Extracting Archive Utility Rate
This program from Gammadyne is used to create a professional quality installation program out of an archive file.
Version 11.3 was shipping as of June, 2004.
FileStream, Inc Rate
FileStream makes quite a few compression-related programs, including TurboZip and TurboSFX. Release 5.,1 appears to have shipped sometime in the latter part of 2002.
ALZip Rate
Another archiver, this one supports ZIP, ACE, RAR, TAR, and ZOO formats. This appears to be a Korean product – the web page is bilingual.
PicoZip Rate
PicoZip is an award winning file compression utility that runs on all 32-bit Windows platforms such as Windows 95, 98, ME, NT4, 2000 and XP. It is extremely easy to use, yet contains many advanced features that helps you create or unzip ZIP files, as well as most other popular archive formats like RAR, ACE, LHA, JAR, etc.
PicoZip 3.0 shipping as of July, 2004.
DataCompression.info user Derek P. had this to say: This is one of the best Zip Utilities out there! The Batch Testing of Archives tool is fast and accurate!!! Other Zip Utility Makers need to take notes!.
Compressia Rate
Compressia is a BWT-based archive utility with particularly high compression ratios. On Calgary, Canterbury, ACT-Text and ACT-Exe it surpasses all other BWT utilities. On Canterbury corpus it also surpasses all PPM utilities. Beta version 1.0 is available on the web site as of February, 2003.
DataCompression.info reader Juan L. said It is by far the best I’ve tried.
ACB 2.00c Rate
George Buyanovsky’s ACB archiver. The proprietary compression scheme used by ACB gives consistently impressive compression ratios. Those ratios come at the expense of much RAM and CPU time.
UUNet FTP Site Rate
This ftp site has copies of Zoo, ARC, gzip, and zip, in some cases for multiple platforms.
WinAce 2.11 Rate
WinAce released a new version of their archiving program at the end of 2000, promising exciting new features, such as support for Gzipped files, proprietary EXE, sound, and picture algorithms, and the usual list of extras.
DCL user comment: I have never seen such a lovely archiving program. The best I have used so far. Winzip can not touch this one! .
ZipWave Rate
A shareware visual archiving program that advertises that it supports 15 popular archive formats. Note the link to the French version of the program and web page.
Advanced Zip Repairer Version: 1.20 Rate
Advanced Zip Repairer(AZR) is a powerful tool to repair corrupted Zip files and Self Extracting files(SFX). It can recover your data in zip archives as much as possible, so to minimize the loss in file corruption. Currently AZR can fix all sub-types of zip files and all kinds of self-extracting files, also it will provide a tiny exe stub when repairing SFX files. Moreover, it has integrated with windows shell and supported drag & drop operations, which will make you repair files easily and quickly.
Squeez – The Ultimate Compression Utility Rate
Squeez is a fast file compression application, supporting many different archive formats. It reads and writes files in the formats ACE, ARJ, BZIP, CAB, GZIP, LZH, RAR, SQX, TAR, UUE and ZIP without any additional software. Unlike many other archivers, Squeez can read and write ZIP files (so called Zip64 archives) that have no limits regarding their maximum size or the maximum number of files within. The new SQX archive format supported by Squeez is an open archive format without any limits regarding the maximum archive size or the maximum number of files within. Special compression algorithms for executables (EXE, DLL) and multimedia files as well as a fast compressor for WAV files can usually compress content 8 to 30 percent better than ZIP or ARJ files.
AIN Archiver v 2.3 Rate
Full-featured archiver AIN, the extracting utility AINEXT and the EXE-files compressor AINEXE. Compression/extraction methods used in the AIN archiver excels noticeably those used in any well-known archivers, such as ARJ, LHA and PKZIP, in both the compression rate and the performance.
One user who rated this product for the DCL said Super Product!
FEI STU Bratislava,Slovakia,Europe Rate
A very complete archive of compression programs, freeware, shareware, source, archviers, compressors, etc. They have it all. At last count this site has at least 1000 compression downloads
SBC Archiver Rate
The submitter said: SBC is Burrows Wheeler Transform based file archiver. It’s one of the fastest BWT implementations with high compression ratio. SBC also introduces a high security options with a number of strong encryption algorithms.
SBC appears to be shareware. Comment from a DCL user: Cool archiver; the author has made great effors to make it really fast and also added a lot of heuristics to behave well on multimedia data.
RAR Home Page Rate
This seems to be the official home page for RAR and WinRAR. RAR is a high performace archiver that is loved by many.
WinRAR 3.30 is out as of January, 2004.
CODEC v3.10 Rate
CODEC is a software package that focuses on the non-destructive compression/decompression and the encryption/deciphering of one or more files in the same work session.
LIMIT version 1.2 — Data Compression/rchive utility Rate
LIMIT is a fast and compact data compressor/archiver. The compression and decompression routines have been written entirely in 80286 assembly, so it runs faster than many other archivers. LIMIT also compresses better than other archivers; it uses a compression method based on 32K sliding window dictionary plus huffman encoding, similar to LHA/PKZIP/ARJ, but with some improvments.
ZipGenie Rate
ZipGenie is yet another archiver that supports a scad of formats, including zip, cab, arj, lha, lza, arc, gz, tar, zoo, gzip, rar, tgz, ace, jar, pak, and z. The author says that the download is multilingual, with help in German, English, Spanish, and French.
RAR 2.06 Rate
The RAR Archivever – text UI.
An enthusiastic DCL user had this to say about RAR: The king of archivers, period. Nothing comes close – no laughable zippers, the slow Jar, or the useless program that tries to be a competition for RAR (winace). This is the best! I’ve used RAR since its DOS beginnings, for years, and it only gets better and better!.
Advanced CAB Repair Rate
This tool is touted as being able to repair corrupt CAB files. It scans the file and recovers as much data as possible.
Version 1.1 is shipping as of November, 2003.
Reader Antonio P. says: Relatively useful but very expensive for infrequent use.
Streamline Archival Utility Ver 1.00 Rate
SAR is a simple archival utility that uses the Huffman algorithms. It has been designed to utilize a single executable for all functionality and has proven to be more effective than most archival utilities on the market today. Although SAR does not have a lot of the commands other utilities have, it more than makes up for it in compression and ease of use. Future releases of SAR will continually include more functionality.
JRCHIVE 1.10 Rate
JRchive is a program for compressing and storing files in an archive. It has a “concatenated archive” option that puts the files in the archive first, then compresses it for better compression ratios.
CuteZIP 2.0 Rate
Those cute people at globalscape now have a cute zip program. It’s interesting because it not only handles Zip files, but also CAB files.
Version 2.1 shipped in April, 2003, andding strong encryption and command line functionality.
PowerArchiver Rate
Yet another Windows archiving program. PowerArchiver comes with a nice long list of supported formats: ZIP, CAB, LHA (LZH), TAR, TAR.GZ, TAR.BZ2, BH, RAR, ARJ, ARC, ACE, ZOO, GZ, BZIP2, XXE, and UUE. Plus a built-in viewer for JPG, GIF, and a few other formats.
Release 9.0 of PowerArchiver shipped July, 2004.
Disintegrator Rate
DST – shareware archiver
ShipInBottle Archiver Rate
This is a Russian language web site, so I’ll have to apologize in advance for any mistakes. As far as I can tell, this is a PPM-based archiver. I can’t tell if it’s free or not, so I’m listing it as both!
ARX (R) archiving utility v 1.0 Rate
Another shareware archiving utility.
Packing program BSA 2.00 Rate
Archiving program that advertises support for DOS, Windows, NT, OS/2, QNX, and UNIX. This distribution has no docs, but the ACT page indicates that this is shareware, so until further notice I’ll label it as such.
Stuffit Deluxe Rate Stuffit is the archiver of choice for those on the Apple platforms. Stuffit has been running on MacOS and OS/X for years, and over time added support for Windows, Linux, and Solaris. Stuffit comes in standard and deluxe versions, with a trial download available for the standard edition.
Version 8.0.2 shipped in December, 2003
Official RAR/WinRAR Registration and Support Site Rate I guess this is where you go to register or get support for your copy of RAR or WinRAR.
Rarissimo Rate Rarissimo is a file utility to automatically compress and/or uncompress files, companion for the award winning compression program WinRAR. Distinguishable from other compression solutions by its ability to fully preserve NTFS alternate streams. This feature provides automatic compression/uncompression for Macintosh files stored on NT volumes preserving their filenames and peculiar structures – it means for example that you can use Rarissimo to send and receive Macintosh files using any standard FTP process (and not only Mac-based programs).
DataCompression.info user Marie M. said: This utility is very specialized so not easy to find. It is a great help to transfer Mac files without a special Mac ftp utility.
MacRAR Rate MacRAR is the only RAR tool for Macintosh. Based upon Eugene Roshal’s sources and including a Mac interface, the package is delivered as shareware.
ACDZip Rate ACDZip is a zipping and unzipping program that gives you the power to compress image, audio, video and document files. It includes fast image previews and is ideal for opening zip files, backing up files, saving hard disk space, preparing files for distribution and protecting them with encryption and passwords.
DeepFreezer for Windows95/NT Rate The documentation for this program is in an unknown language. It appears to be an archiver that includes a developers kit.
CrossePac Rate A data compression utility. The internal documentation states that this program can create archives using 7 bit ASCII only for maximum portability.
Aladdin Systems, Inc. Rate Aladdin makes quite a few different software products, but the one we are concerned with is Stuffit, probably the best known archiver for the Macintosh platform.
Hamarsoft Rate I don’t know if Hamarsoft is still in business, but you can still get a copy of HAP here. Harald Feldmann was Hamarsoft.
Archive & Restore Rate With Archive & Restore, you can save, stow away and restore files easily. Stowing away files will recover space on your hard disk, increase clarity and reduce administration efforts. Saving versions of your files lets you return to a previous state, for example, while developing a project.
PAK The File Compression Utility Version 2.51 Rate PAK is a utility to create and maintain file archives in compressed form. There are several advantages to compressing files. On a hard disk, most files are accessed infrequently. Reducing the size of these files allows more of them to remain on the hard disk, where they are more accessible than on a floppy in a file cabinet, and frees disk space for other use.
CRUSH v1.8 Rate Fed up with limited compression performance of Stacker, PKZIP, UC2, ZOO, ARJ and LHA? CRUSH will usually give 5%-50% improved compression over any other DOS compression tool, and yet allows the user to continue using the archiver already in use. CRUSH is fast and the ideal choice for users keen to save disk space. I can’t help but note that the last update of CRUSH was in 1995!
ARC – File Archive Utility V 6.02 Rate ARC is used to create and maintain file archives. An archive is a group of files collected together into one file in such a way that the individual files may be recovered intact. ARC automatically compresses the files being archived so that the resulting archive takes up a minimum amount of space.
Garbo repository for PC archiving programs Rate This FTP site has copies of a wide variety of archiving programs. Includes current programs such as PKZip, ARJ, and RAR, as well as historically relevant programs such as PAK and ARC. Look at 00index.txt for a directory of what’s on hand.
Zipey Pro Rate Another archiver that supports ACE, ARJ, RAR, ZIP and perhaps more.
Version 3.0 is shipping in March, 2004.
Batch Zip Toolkit Rate Despite the name, this is simply an archiving program that supports the usual gamut of compression formats, including Zip, RAR, ACE, etc.
Version 3.00 seems to be shipping in December, 2002.
Xipped Rate Advertised as The world’s most versatile and powerful archive utility! Available as shareware or free w/ads. Supports various formats, does conversions, works with the Windows shell.
Advanced Encryption Package 2001 Rate This archiving package works with zip files, creates encrypted archives, wipes files, etc.
ArjFolder Rate ArjFolder is a utility that makes it easy to read or write ARJ and ZIP files, and to read a slew of other file types. Sit can be viewed in French or English.
ACT – Mac Archiver Index Rate Jeff Gilchrist maintains the well known Archive Comparison Test site, which pits all the compressors of the world against one another. This page on that site has links to the all those archivers. Lots of links.
ACT – PC Archiver Index Rate Jeff Gilchrist maintains the well known Archive Comparison Test site, which pits all the compressors of the world against one another. This page on that site has links to the all those archivers. Lots of links.
Compact Pro Rate Compact Pro is a shareware file compression and archival utility for the Mac. It compresses and stores files in “archives” which may span multiple diskettes. Compact Pro supports data encryption (US and Canadian users only) and self-extracting archives.
Pack Up & Go Rate Shareware compressor for the Mac. Web site claims it handles universally standard archives, a bit vague for my taste.
Squeez Rate I believe this is the US sales home for the product Squeez, which makes its home in Germany.
MegaSafe Rate MegaSafe is advertised as being “one finger archive control of your critical data.” I’m not sure what that means, and there is not much more description than that on the web site.
AckerPack – Smarter Folder Compressor Rate This commercial Win32 program is designed to take a folder and turn it into self-extracting archives in a proprietary format. Commercial, no free trial, money back guarantee.
ZipZag Rate Yet another Win32 archiver. Distinguishing features are: support for over 125 archive types, benchmarks that show it beating 7-Zip, WinRar, and WinAce for compression ratios.
Planet Zip Suite Rate Another Win32 archiving program, supporting the Zip format and scads of others, as well as providing SFX, encryption, a file splitter, and best of all, a free world clock!
MKS Unix Utilities Rate MKS makes UNIX utilities available on other platforms. Naturally, this includes pack, unpack, mkszip, and so on.
xPress – Cross Platform File Compression Rate These guys appear to be selling a conventional file compressor that works on quite a few different desktops and mainframes. The product description on the web page manages to obscure the facts with a lot of marketing-ese, so I’m a bit fuzzy on the details.
ARJ Software Downloads Rate This page has the official releases of ARJ, UNARJ, JAR, and so on. This includes the free source to UNARJ and the ARJ32 command line archiver.
ARJ32 version 3.11 was shipping as of 12/2003.
ARJ version 2.82 was shipping as of 12/2003.
CAB Station Rate This is the home page of CAB station, and inexpensive program that manipulates Microsoft CAB files.
Aladdin Dropstuff Rate Another product from Aladdin, makers of the world-famouse Stuffit program for the Mac. DropStuff comes in versions for the Mac and Windows, and will store archives in either Zip or Sit formats.
ArchivePro 2000 Rate ArchivePro isn’t a zip program, it’s a database for all the files you’ve stored. In the process it often compresses files for you, which is how it ended up in my database.
TurboZip Rate TurboZIP is an Archive, E-Mail Manager and Auto Backup tool. It opens major archive and E-mail formats. It offers the unique capabilities to internally view, print, copy, launch, and virus scan files within ZIP and E-mails without unzipping; unique ZIP Set and Multi-threading operation for simultaneous zipping, unzipping, auto backups..
TurboZip 5.1 appears to have been released sometime around January, 2003. Unfortunately, the FileStream web site doesn’t provide any sort of release history for this product, so it’s impossible to determine exactly when the release shipped and what features were added in 5.1.
PowerZip Rate An archiver that manages the usual gamut of archive types. Wizards and stuff.
Release 7.02 was shipping in May of 2004.
WinArj Rate A version of Arj written specifically for 32 bit Windows. From Robert Jung, the author of the ARJ archiver.
Ultimate ZIP Cracker Rate A program designed to crack lost passwords for zip and arj files.
TurboZip Express Rate TurboZIP Express is tightly integrated with Windows Explorer so you can ZIP, UnZIP, CAB, UnCAB, plus E-mail files, all in one quick action. You can compress files to units of any size and output to HD or FD. It lets you internally view, print or even edit files within Zip..
ArchiveXpert Rate ArchiveExpert supports the standard Zip format, as well as CAB, LHA, LZH, plus extraction support for ARJ, ARC, PAK, RAR, as well as other formats. The 2.02 release shipped in August of 2002.
ArchiveXP 2003 Rate An archiver that supports 31 formats. ArchiveXP uses the 7-Zip compression format to handily beat Zip-based compressors when it comes to archive size.
SP83 of ArchiveXP 2003 was released in January of 2003.
Stuba mirror site Rate A mirror site for the big compression software site. See 0index.txt for a list of what’s here, an unbelievably large treasure trove.
DropZip by Aladdin Systems Rate A commercial program that supports both the Stuffit and Zip formats. DropZip is available for both Mac and Windows platforms.
CiderPress Rate CiderPress is a Win32 programmer that is designed to support Apple II archiving formats. Full support for ShrinkIt (NuFX) archives, plus a bunch of features that provide glue functoins for dealing with AppleII stuff on modern Windows machines.
Zipbit Rate Zipbit is yet another inexpensive Win32 archiver with support for a wide range of archive types. Creates SFX files, integrates with Windows Explorer, and has localized versions for English, German, and Russian.
Version 1.05 is shipping as of April, 2003.
ARJ

ARJ 2.75 Rate
An archived copy of ARJ 2.75.
ARJ for Linux and FreeBSD Rate
Andrew Belov, from ARJ Software Russia, has announced the release of ARJ for Linux and FreeBSD. Links on this site to the OS/2 version as well, if you’re in the market for that.
Password recovery software Rate
Elcom makes password recovery software, which includes support for Zip and Arj files.
Jazz interface for the JAR file compressor Rate The folks at Dark Horse Industries like Robert Jung’s JAR compressor. So much so that they created a graphical front end for it. Get it here.
Audio

RealNetworks Rate
Makers of lots of audio and video compression stuff.
ezConverter Rate
ezConverter is a program that is designed to make it easy to convert your audio files between various formats. Converts between WMA, MP3, MPEG, and many more formats. ezConverter also takes input directly from your sound card, allowing you to record from analog inputs or from the output of other programs. The publisher advertises it as fast and easy. You can download a trial version from the web site, but registration is going to set you back roughly $US 25.
Version 1.1 was shipping as of March, 2003.
Blaze MediaConvert Rate
This product performs a huge number of conversions among different media types. Want to convert your huge collection of MP3 files to WMA? No problem. MPEG-2 to AVI? No problem. MediaConvert even handles some unusal conversions, such as video to animated GIF. And naturally, a huge number of conversions between various image formats, including GIF, JPG, PNG, and a host of additional types.
Release 2.3 shipped in Julyy, 2003.
TwinVQ Rate
An audio compression format invented at NTT’s Cyber Space Laboratories. Get your player and compressor right here. (English avaible by following the sharp-eyed link.)
Windows Media 9 Series Rate
Microsoft’s web page for all things releated to the new Windows Media Player and more. At this time you can download the beta version of the new player, get information, and sample various media.
Reader Serg N. commented: Very good quality, support for [very] low bitrates, lossless mode. It’s not open source, but it’s free!
Clipstream 2.0 Rate
Clipstream is a product that compresses audio to either 20Kbps or 32 Kpbs, depending on the speed of the connection. A java applet on a web page is used to decode the stream and play it over the sound card of the target computer. The web site has demos of several types of sound. Update: Clipstream has java applets for both video and audio!
Sound Compression from an Imaging Company Rate
The PIC Sound Processing System (SPS) uses the ELS arithmetic Coder from Pegasus. Here are the latest raw figures for the 4 most common sound formats. 4 formats using the full dynamic range (-32768..32767 for 16-bit and 0..255 for 8-bit).
Audio Signal Processing Software Rate
Includes editing software, file formats and converters, codecs, and links. This page is at the University of Hannover, Germany. While there appears to be a wealth of software on this site, it would appear that you need special privileges to get access to ti.
MediaOne+ Rate A relatively standard Windows media player. Handles DVD, MP3, DivX, etc.
Advanced MP3 Converter Rate This conversion tool will convert between several audio formats, including WAV, OGG, and MP3. Supports ID3V1 and V2, plus other goodies.
ACDZip Rate ACDZip is a zipping and unzipping program that gives you the power to compress image, audio, video and document files. It includes fast image previews and is ideal for opening zip files, backing up files, saving hard disk space, preparing files for distribution and protecting them with encryption and passwords.
Windows Media 9 Final Release Rate This page has links to download all the various components of Windows Media 9, including the media player, codecs, encoders, embedded toolkits, and more.
The Official daxaif Home Page Rate From the site: daxaif is a no-loss audio compression program which performs live capture or converts audio files, movie sound tracks, or audio CD tracks into a compressed “.dax” file format. This format allows fast locating and selection of audio passages through the use of a clickable compression-factor map. The selections can be played or saved in uncompressed AIFF or further compressed to AIFC format using any QuickTime-supported compresser. .
WMA MP3 Recorder Rate WMA MP3 Recorder turns your computer into complete audio recording studio. You can record sound from any internal or external source into WMA/MP3 format sound file directly without use additional disk space.
Version 5.60 is shipping as of April, 2003
Advanced WMA Workshop Rate This product is used to convert audio files from one format to another. The programs know how to do various conversions between WMA, MP3, and Ogg Vorbis. It’s also smart enough to do CD ripping. This appears to be shareware.
Building Windows Media Player and Windows Media Encoder Plug-ins Rate Just what is says, Microsoft’s tutorial on building WMA plugins.
SFZip Rate This is a Win32 program that manages SoundFont files. These files are the ones used by Creative Labs to program their Midi cards. I think.
MediaZip Rate MediaZip is a Windows program that performs lossless compression/decompression and manages archives of media files (Sound and Picture). Welcome to the MediaZip home page.
MP3 To WAV Converter Rate MP3 To WAV Converter is designed for converting MP3 to WAV and converting WAV to MP3. It converts batches of MP3 to WAV or WAV to MP3 on-the-fly. Play MP3/WAV files, edit Mp3 file’s ID3 text, and search MP3 or WAV files from a folder or the whole disk.
MUSICompress Home Page Rate The home page of the MUSICompress lossless compression method.
WMA To MP3 Converte Rate WMA To MP3 Converter was written for converting WMA to or from MP3/WAV files. So, with WMA to MP3 Converter, you may convert WMA to MP3, convert WMA to WAV, convert WAV to WMA, convert MP3 to WMA.
Ace Media Player Rate Ace Media Player supports an impressive list of media types, including Real, MPEG, DivX, QuickTime, VCD, WMF, and of course, MP3. This is a commercial product, but you can get a 30 day eval copy.
Version 2.2 of Ace Media Player shipped in March of 2003.
Power WMA Recorder Rate Power WMA Recorder is a program that can create WMA files from any available sound source directly without using any additional disk space. In addition to supporting Microsoft’s WMA format (including the variable bit rate option), Power WMA Recorder can encode directly to MP3 format.
Version 1.34 is shipping in March, 2003.
wmplugins.com Rate This site describes itself as The ultimate resource for enhancing your Media Player 9 Series for Windows. By this they mean plugins, themes, skins, visualizations, etc.
jetAudio Rate Another company determined to swim upstream with a commercial media player. Although in this case, jetAudio Basic is free, jetAudio Plus is the the commercial product. You’ll pay for the upgrade if you decide you need support for creating MP3 and MP3Pro files, broadcasting MP3 files, and converting files to MP3 or MP3Pro.
jetAudio has a nice looking UI with some alternative skins. Version 5.01 is shipping as of March, 2003.

i-Sound WMA/MP3 Recorder Professional Rate This app from AbyssMedia is advertised as being able to turn your computer into complete audio recording studio. That means you have the ability to record from external inputs directly to MP3, OGG, WMA, or WAV format. Includes niceties such as MP3 and OGG tag editors, Voice Activated recording, skin support, and more.
Version 6.05 is shipping in November, 2003.
MMPlayer Rate MMPlayer is a Mobile Media Player for the Palm OS. It supports a wide variety of audio formats, including Windows Media, MP3, Ogg and WAV. Video isn’t supported in the current release, but is anticipated as part of MMPlayer 2.0.
Helix DNA Client Rate Real is making their client software available in an Open Source program. Download this software and you can develop your own MP3 player! Free of royalties if you are distributing it for free – commercial products pay a royalty.
Windows Media® ASF Viewer 9 Series Rate Microsoft supplies this free tool as a way for developers to check their files for validity before shipping. Looks like it knows how to inspect ASF, WMA, and WMV files.
recorder.xhead Rate This app allows you to both record and play sounds on your Mac in various formats, including MP3 and MP4. Also includes a bulk conversion utility for changing formats, and has the ability to export to iTunes.
Windows Media Diagnostic Tool Rate Having trouble with your Windows Media Player? This program gathers up all your information and stores it in a compressed file that you can quickly mail to your tech support pal in Redmond.
Audio Conversion Wizard Rate Audio Conversion Wizard is “All to All” converter of digital audio formats with friendly Wizard-style interface, which helps you easily convert:
WMA to MP3, OGG Vorbis, WAV PCM
WMA to WMA (resampling)
MP3 to WMA 8, OGG Vorbis, WAV PCM
MP3 to MP3 (resampling)
OGG Vorbis to WMA 8, MP3, WAV PCM
OGG Vorbis to OGG Vorbis
with ID3 Tag v2 copying and creation.
Windows Media 9 Authoring Utilities Rate Creating Audio and Video content with Windows Media 9 is made possible by the authoring tools listed on this page. At the time this is entered, the list of tools includes:
Lossless to PCM Converter
Mono to Multichannel Wave Combiner
Video Compression Manager
Plug-in for Adobe Premiere 6.5
Windows Media 9 Capture
Welcome to Advanced RealMedia Repair Homepage Rate Advanced RealMedia Repair is a package that will help you repair your broken RealMedia files. Supports both video and audio files.
Media Wizard Rate Description from the web site: Media Wizard is a powerful, all-in-one multimedia application supporting playback of all popular formats, audio and video conversions (CD to WAV; CD to MP3; CD to WMA; CD to OGG, WAV to MP3; MP3 to WAV; WAV/MP3 to WMA; WMA to WAV/MP3; WAV/MP3 to OGG; OGG to WAV/MP3; WAV/MP3 to CD; AVI to MPG; MPG to AVI; etc.)
This is a Win32 program, and version 8.0 is shipping as of April, 2003.
AVI-GIF Rate This is a batch image converter that lets you go back and forth between AVI and GIF. I don’t know what the practical limits are on the size of animated GIF files, but I’ve seen some pretty cool short videos in the format. This looks to be the way to create them.
Release 1.09 shipped on July 15, 2002.
All Converter Rate Yet another conversion program: All Converter is a powerful, all-in-one, multimedia application converting the media files among the most popular media formats.With All Converter,you can convert MP3 to WAV,MP3 to WMA ,MP3 to OGG,MP3 to VQF, WAV to MP3,WAV to WMA,WAV to OGG,WAV to VQF,WMA to MP3, WMA to OGG,WMA to VQF,OGG to MP3,OGG to WAV,OGG to WMA,OGG to VQF,VQF to MP3,VQF to WAV,VQF to WMA,VQF to OGG, normalize files,and support ID3 tag v1, v2 to file name conversion and vice versa.
Backup

Argentum Backup Rate
This backup program stores your data in standard Zip files, created either manually or automatically. The usual host of backup features are supported, such as the ability to backup the registry, E-mail messages, your address book, and so on. You can download a 15-day trial version of this commercial program.
It appears that version 2.10 of this program shipped in January, 2004.
Backup32 Rate A Win32 backup program that stores files in a Zip compatible format.
Automatic File Archiver by JSPayne Rate An archive manager that has some built in functionality that helps you with your backup requirements. Automatic archiving in the trusty Zip format.
AM-Zip Rate Lots of folks (including me) perform system backups into Zip archives. Over the years I became leery of proprietary formats used by various manufacturers of tape drives, removable disks, etc. Zip files give me a much better feeling, and make it a lot easier to browse through my backups. Martin Aignesberger must feel the same way, because he has created a product that performs daily backups into Zip files. This is a commercial product, but he does offer a 30 day free evaluation.
Back2zip Rate A shareware backup program that saves your stuff to the Zip format. We like that.
TurboZip Rate TurboZIP is an Archive, E-Mail Manager and Auto Backup tool. It opens major archive and E-mail formats. It offers the unique capabilities to internally view, print, copy, launch, and virus scan files within ZIP and E-mails without unzipping; unique ZIP Set and Multi-threading operation for simultaneous zipping, unzipping, auto backups..
TurboZip 5.1 appears to have been released sometime around January, 2003. Unfortunately, the FileStream web site doesn’t provide any sort of release history for this product, so it’s impossible to determine exactly when the release shipped and what features were added in 5.1.
Back4Win Backup Software Rate A backup program that uses the standard Zip format for compression. Yes, you can do backups with just a Zip program, but then you wouldn’t get all the cool options here, including disk spanning options, a nice GUI, password options, and more. This product comes in a freeware and shareware version.
Back4Win 2.5 and Back4Win 2.7 are shipping as of April, 2003.
Azguard Rate Another backup program that is based around the Zip standard. Supports deflate64, spanning, and other advanced Zip features. This is Win32 shareware.
Version 2.5.4.53 shipped in December, 2003.
ZipBackup Rate Another Win32 backup program. 30 day free trial, but you have to pay up after that.
Zip Backup to CD Rate A backup program that uses the standard Zip format. Supports complete system restore for Windows ME and 9x. Version 3 will have built in CD and DVD burning support, eliminating the need for an external burner program.
Version 2.34 is shipping as of March, 2003.
Burrows-Wheeler Transform/Block Sorting

Compressia Rate
Compressia is a BWT-based archive utility with particularly high compression ratios. On Calgary, Canterbury, ACT-Text and ACT-Exe it surpasses all other BWT utilities. On Canterbury corpus it also surpasses all PPM utilities. Beta version 1.0 is available on the web site as of February, 2003.
DataCompression.info reader Juan L. said It is by far the best I’ve tried.
SBC Archiver Rate
The submitter said: SBC is Burrows Wheeler Transform based file archiver. It’s one of the fastest BWT implementations with high compression ratio. SBC also introduces a high security options with a number of strong encryption algorithms.
SBC appears to be shareware. Comment from a DCL user: Cool archiver; the author has made great effors to make it really fast and also added a lot of heuristics to behave well on multimedia data.
Transform Rate Transform is a BWT compressor written by Michael Bone. It supports a number of very interesting features, such as automatic Base 64 representation and image output. Shareware.
Version 1.02 shipped in October, 2003.
12Ghosts Zip Rate This package includes 12Zip and 12Zip2. The first version uses Zip compatible compression, and the second uses a BWT variant.
Version 7.0 of the package is shipping as of May, 2004
Data Compression

AOL.COM search: Home > Computers > Software > Data Compression Rate
AOL search page with links to commercial and free data compression programs, and the companies that produce them.
Miliki Super Compressor Professional Rate
This product is advertised as a revolutionary compression package from QuickCAT Technologies. It comes in two versions: a Pro package that compresses documents and images, and a Basic version that compresses only images.
Source and Executables for the Amiga Rate
A huge selection of compression source and executables for the enigmatic Amiga.. I don’t know if this is a mirror site or independent.
FEI STU Bratislava,Slovakia,Europe Rate
A very complete archive of compression programs, freeware, shareware, source, archviers, compressors, etc. They have it all. At last count this site has at least 1000 compression downloads
XTREAM Rate The XTREAM Data Management System (XMS) is a robust, scalable data compression system that offers increased compression ratios and/or reduced compression processing time for efficient data management.
Note: I have to confess that after looking at this web page, I have absolutely no idea what this product does, how one would use it, or what the potential market is.
Archiving Encrypting Tiny File Splitter Rate Oleg Z. has created this program to to split, encrypt with your own unique key, compress and restore to original state large files of any type. The author says the program has an intuitive GUI, and works on most Win32 platforms.
Version 1.0.0.1 shipped on March 6, 2003.
Stuba mirror site Rate A mirror site for the big compression software site. See 0index.txt for a list of what’s here, an unbelievably large treasure trove.
Esoterica/Miscellany

DWG2ZIP Rate
This program lets you compress AutoCad DWG files into Zip archives for distribution.
Version 2.0 is shipping as of May, 2003.
SoftDefender Rate
Soft Defender is a good exe file compressor, which can reduce the file size of 32-bit Windows programs by as much as 50%.In addition, Soft Defender is a perfect product of software protection of applications.With Soft Defender, your application can have anti-debugging, anti-tracer, anti-disassemble, anti-dumping, anti-apihook, file integrity checking functions in seconds. It requires no source code editing or your registration algorithm changing.
ZFilter Rate
ZFilter is the ZIP indexing filter for SharePoint, Internet Information Server, Site Server and Microsoft Exchange server. ZFilter is a library that handles .zip archives and returns indexable text and value properties in a similar way to the MS Office filter and the PDF filter supplied by Adobe. The library handles all zip archives created with WinZip, PKWare and DynaZip, indeed any archive created using the compression format based on PKWare.
Satisfied DataCompression.info user Jim R. had this to say:I’ve been searching high and low for exactly this thing for years, and now I’ve found it, and it works.
CHAOS Self Extractor Rate
CHAOS Self-Extractor is a utility program that creates self-extracting ZIP files for Windows. CHAOS supports a form of encryption that it claims is much stronger than standard Zip encryption.
JAM ™ Version 1.25 Rate
JAM is a transparent hard disk compressor, which enlarges your disk space. With the JAM you will forget about annoying messages like ‘Insufficient disk space…’ with no need to purchase a new hard disk.
ZipSearch Rate A search program for Win32 computers. ZipSearch knows how to look through Zip files and compressed EXEs to find search strings.
Version 1.07 shipping in December, 2002.
GZIPSite Rate GZIPSite is a tool that can compress your web site and allow it to load as much as 50% faster.
AM-Zip Rate Lots of folks (including me) perform system backups into Zip archives. Over the years I became leery of proprietary formats used by various manufacturers of tape drives, removable disks, etc. Zip files give me a much better feeling, and make it a lot easier to browse through my backups. Martin Aignesberger must feel the same way, because he has created a product that performs daily backups into Zip files. This is a commercial product, but he does offer a 30 day free evaluation.
Rarissimo Rate Rarissimo is a file utility to automatically compress and/or uncompress files, companion for the award winning compression program WinRAR. Distinguishable from other compression solutions by its ability to fully preserve NTFS alternate streams. This feature provides automatic compression/uncompression for Macintosh files stored on NT volumes preserving their filenames and peculiar structures – it means for example that you can use Rarissimo to send and receive Macintosh files using any standard FTP process (and not only Mac-based programs).
DataCompression.info user Marie M. said: This utility is very specialized so not easy to find. It is a great help to transfer Mac files without a special Mac ftp utility.
PDFCompress Rate A Mac OS X utility to shrink the huge PDF files created by the Mac Quartz rendering engine.
LuraDocument.jpm PdfCompressor Rate The LuraDocument.jpm PdfCompressor is a Windows application that can be used to automatically (Server version) or manually convert scanned documents to higly compressed PDF files. The supported input formats are TIFF, JPEG, BMP and PNM.
Ultimate ZIP Cracker Rate A program designed to crack lost passwords for zip and arj files.
Absolute HTML Compressor Rate Absolute HTML Compressor is an award-winning tool that optimizes HTML files so that their size is reduced.
CHM2PDF Pilot Rate Convert your CHM help files from Microsoft to Adobe’s PDF format. This is shareware that runs on Win32 platforms.
Fractals

Altamira Group Rate
These guys apparently make a couple of variations on a product called Genuine Fractals. The product is a Photoshop plugin that appears to read fractal file formats and do some sort of scaling. If this is a grotesque misrepresentation of what the product does, feel free to email a correction.
GIF – Compuserve’s Graphics Interchange Format

Trout’s GIF Optimizer Rate
This freeware program is designed to help you reduce the size of your GIF files. There are certain optimizations that can be performed with absolutely no loss of quality, as well as some that can provide additional improvements with some loss of resolution. Best of all, Trout’s GIF Optimizer is completely free.
An anonymous reader complained They call it freeware then make you pay. To be honest, I can’t see any indication of this on the web site, other than the usual request for donations. Somebody correct me if I’m wrong!
GIF Construction Set Pro Rate GIF Construction Set Pro represents the state of the art in GIF animation software. It will assemble your original animations effortlessly through its Animation Wizard, squeeze them down to as close to nothing as possible with its Supercompressor; create eyecatching banners and animated transitions; manage your GIF files; add transparency to existing graphics and a lot more.
Version 2.0.44 is shipping as of February, 2004.
Advanced GIF Optimizer Rate This program is designed to help you squeeze the maximium amount of space out of GIF files while keeping the image quality at an acceptable level. Commercial code, but a free download is available.
Version 4.0 is shipping as of December, 2003.
Ultra GIF Optimizer Rate Ultra GIF Optimizer is a powerful tool for optimizing GIF images. It can makes your web page load faster,save your server bandwidth charges and disk space! This is a commercial product, but it looks like you can download it and have a trial session.
Real GIF Optimizer Rate A GIF optimizer seeks to reduce the size of your GIF files, usually without compromising image quality. Not enough detail on this site to pass judgment, but good GIF optimizers will also let you reduce the number of colors in the palette dynamically, so you can see the effect.
Real GIF Optimizer 3.05 shipped in February of 2003. I wish I could tell you what new features are in this release, but RealMultiMedia Development is one of those companies that doesn’t bother to post release notes on their web site!
Gzip

UUNet FTP Site Rate
This ftp site has copies of Zoo, ARC, gzip, and zip, in some cases for multiple platforms.
GZIPSite Rate GZIPSite is a tool that can compress your web site and allow it to load as much as 50% faster.
HTML2Zip Rate This product compresses your web pages using the gzip format, which is readable by virtually every modern browser. Compressing the pages this way can do a lot to improve your page loading times.
Version 2.0 is shipping in April, 2003.
Image Compression

DAX source code Rate
This code is reputedly good for compressing B/W images. The web site refers to it as Difference Adaptive compression. It’s patented.
RICAZip.com Rate
RICAZip.com has proprietary lossless image compression technology called RICA (Reversible Image Compression Algorithm). RICA retains original file formats (e.g. TIFF, DICOM, BMP, TGA, PGM etc.). RICACom says We have yet to find any method that provides better compression ratios (for truly lossless), including wavelet. On a PII 450MHz RICA compresses @ 6MB per second and decompresses at 12MB per second.
Available as a standalone image archive app, Adobe Photoshop Plugin, Browser Plugin, and RICA SDK.
DCL reader Karen H. says: Evaluation of this product demonstates excellent compression ratios and it is also very fast compared to other methods I have used.
MrSID by LizardTech Rate
LizardTech has developed a portable image format called MrSID that is used by people who have huge files and want to render them in a nearly lossless manner. I think the idea is to render it on a given output device using just as many pixels as is absolutely necessary. Looks like they are pitching this stuff to the mapping and medical industries.
Miliki Super Compressor Professional Rate
This product is advertised as a revolutionary compression package from QuickCAT Technologies. It comes in two versions: a Pro package that compresses documents and images, and a Basic version that compresses only images.
Where can I get image compression programs? Rate
The comp.compression FAQ attempts to answer this question.
Blaze MediaConvert Rate
This product performs a huge number of conversions among different media types. Want to convert your huge collection of MP3 files to WMA? No problem. MPEG-2 to AVI? No problem. MediaConvert even handles some unusal conversions, such as video to animated GIF. And naturally, a huge number of conversions between various image formats, including GIF, JPG, PNG, and a host of additional types.
Release 2.3 shipped in Julyy, 2003.
ReaConverter Pro Rate
This nifty program performs batch conversions of programs from a wide variety of types, including JPEG, BMP, TIF, PNG, and the usual other suspects. Lots of other features are added to the mix, including such goodies as watermark insertion, cropping, sharpening, blurring, etc.
Version 3.0 shipped in April, 2003.
MyPhotoZip Rate
These guys are claiming a quantum leap in image compression! It looks like you can get a 30 day free trial of this product. The affiliate marketing program for MyPhotoZip is kind of goofy, see more about it at ecomecom.net.
Visitor Tim A had this to say: A demo of MyPhotoZip is available on CNET, ZDNet (possibly others). My first impression is that it’s very similar to JP2. Lossless compression performance is virtually identical on a few test images. Nothing special to talk about :(
Donald J. was a bit more enthusiastic: I have run several tests on this product and the quality compared to JPEG is far superior. For a raw TIFF image of 10 MB or more the file size can be compressed as much as 1000 to 1 while still maintaining decent quality if you adjust the color portion to a higher number.
http://www.barrt.ru/parshukov/imcomp.htm Rate A shareware image compression program that supports a ton of different formats.
ACDZip Rate ACDZip is a zipping and unzipping program that gives you the power to compress image, audio, video and document files. It includes fast image previews and is ideal for opening zip files, backing up files, saving hard disk space, preparing files for distribution and protecting them with encryption and passwords.
Power Compressor Rate Image Power makes this product which compresses documents using JBIG, GIF, and JPEG2000 encoders. This product is supposed to help you with web publishing, archiving, and image management.
AutoImager Rate Full-featured batch image processing and conversion software. Over 70 image formats are supported, and the software provides an extensive array of image enhancement, editing, and processing operations. All processing and conversion operations have numerous options that can be optionally set for maximum control. The entire application is highly customizable. AutoImager also offers complete command-line support. With over 130 configurable command-line choices, it’s easy to create batch files to perform image processing tasks which may need to be done routinely. A list of available features far too long to list here.
BMPSqueezer Rate An interesting program that takes an image and squeezes it down into a Java applet. Shareware, so you can give it a spin for free.
Zip-I-Mage Rate This archiver is built specifically for support of image archiving. Supports popular formats such as JPG and BMP.
MediaZip Rate MediaZip is a Windows program that performs lossless compression/decompression and manages archives of media files (Sound and Picture). Welcome to the MediaZip home page.
ReaCompressor Rate ReaCompressor is an image compression tool that is designed to assist you in preparing images for the web, emailing, etc. It lets you choose from various formats: JPEG, PNG, GIF, and TIFF, and shows you the results of the compression on screen.
Version 1.8 shipped in October, 2003, and added support for JPG region specific compression and over 340 input formats.
Internet

Artera Turbo Rate
These guys describe their product as Virtual Broadband, implying that it speeds up your dialup connection to the point that you can’t believe it’s not broadband! It appears that the product routes requests for web pages through their network, sending you to pages that have been compressed using their proprietary techniques.
User Paul was quite pleased with the service, saying All in all I was suitably impressd especially when I tried in on my lap top with my GSM connection. Cute to see everything speed up the way it did. .
w3compiler Rate
This is a compiler for web pages, that uses various techniques to squeeze the fat out of your web pages. This includes things a simple as white-space reduction and as complex as JavaScript compression.
Ron M. had this to say: This is a great program, very highly recommended for Web developers. It lets you write your code full of comments and extra space for readability, and then strips it all out automatically for the live site. My pages have been noticeably faster & very hard to decipher the code on the other end. It’s been reliable and easy to get used to.
TurboIIS Rate
A server and download accelerator for your Microsoft web server. The site says that TurboIIS is an advanced component for Microsoft Internet Information Servers, designed specifically with the aim of lowering band consumption, accelerating download times of static and dynamic content, and preventing redundant access to database resources. 30 day trial download available!
Reader Alfred S. had this to say: Very impressive performance compared to other similar products.
Version 4.0 is shipping as of December, 2003.
OutlookZIP Rate The OutlookZIP it’s an Add-On for Microsoft® Outlook. It makes easy for you to compress the files that you attach to Microsoft® Outlook e-mail messages. OutlookZIP adds three buttons to Outlook toolbar making the usage simple easy. OutlookZIP works only with Outlook 2000, Outlook XP (2002), and Outlook 2003. It does not work with Outlook Express.
WebZIP Rate This commercial product will zip up entire web sites and download them to your PC. You can then view them off line, at your leisure.
ZipEnable for IIS Rate Unlike the compression built into IIS 4 and 5 (Windows NT/2000), IIS 6.0 offers out-of-the-box compression embedded into the core Web server code itself, allowing for extremely fast HTTP compression with minimal resource penalties.
Version 2.0 is shipping as of May, 2004.
Attachments Zip Compressor Rate This commercial product takes care of managing your attachments. It appears to do this transparently, so you don’t even have to think about zipping up a big attachment before sending.
VIGOS Website Accelerator Rate Vigos makes software that lets you compress web pages before delivering them to your customers.
HTML-Optimizer Rate This program is designed to optimize your HTML source files by removing unnecessary characters, duplicated tags, and so on. Yes, this counts as Data Compression! Note that this link points to the Windows version of the program, but there are also two different Mac versions which you can easily find.
Version 7.82 was shipping in october of 2003.
HTML Page Guardian Rate This product is used to protect the source of your HTML pages, which it does using “three layers of encryption.” I don’t know how that works, but they do advertise that LZW compression is an optional part of the process, so they earn a spot in DataCompression.info.
Advanced HTMLCoder Rate This product is designed to optimize, compress, and encrypt your HTML pages, which makes them load more quickly and protects them from casual copying.
WebWrap Rate WebWrap is a small 3-in-1 utility program to compress and/or code your HTML web files. It uses either a modified LZSS algorithm or the URL encryption procedure, and can reduce the size of your files by more than 50%. It also renders the source of any HTML pages you have created, your design features and your scripts for example, inaccessible to easy viewing or simple clip and paste procedures. The “WebWrapped” files you create are self-extracting and do not require any third-party software. In addition to compressing and coding your HTML files, you also have the opportunity to add automatically a password protection script.
httpZip Rate httpZip uses standard algorithms to compress web pages streaming out of your IIS server. This commercial software adds support, installation programs, and administration to provide you with something a cut above some of the free alternatives.
TIS Turbo Virtual Broadband Rate This system uses data compression and other optimization techniques to speed up your dialup Internet connection. This sytem works with any ISP or provider.
HTMLCompact Rate HTMLCompact is a commercial program that squeezes your HTML pages, giving you faster downloads and increased user retention. It appears that this is done using some sort of compression that is executed in JavaScript.
Version 2.0 of this product is shipping as of August, 2003.
SlipStream Internet Acceleration Rate SlipStream Data, using our patented proprietary data compression algorithm, provides Service Providers and Corporations with solutions that reduce bandwidth and increase the speed of Internet access using dial-up and wireless connections.
Version 3.0 of SlipStream is shipping in May, 2003.
HTML2Zip Rate This product compresses your web pages using the gzip format, which is readable by virtually every modern browser. Compressing the pages this way can do a lot to improve your page loading times.
Version 2.0 is shipping in April, 2003.
JPEG

JPEG Cruncher Pro Rate
JPEG Cruncher is a commercial app that lets you squeeze the heck out of your images while keeping them looking as nice as possible.
Motion-JPEG CODEC Rate
MainConcept makes a codec that encodes things in the Motion-JPEG format.
Advanced JPEG Compressor for Windows Rate
A program that helps you cook up the optimal version of your JPEG file.
Interactive JPEG Optimizer Rate A tool to help you reduce the size of your image files with little or no reduction in image quality. Demo version available, fully functional but stamps output files with a “Demo” label.
2JPEG Rate 2JPEG is a graphics converter allowing you to convert images to jpeg format from 50+ image file types including conversions from bitmap to jpeg, from gif to jpeg, from tiff to jpeg and so on. The program has no windows interface and is fully optimized for working in background mode.
JPEG Wizard by Pegasus Imaging Rate For those individuals looking for an application that deals with all aspects of JPEG imaging–The JPEG Wizard is it! The JPEG Wizard is based around the premise that altering and processing an image at the algorithmic level instead of the visual level greatly preserves the quality of an image.
JPEG Imager JPEG Imager Rate JPEG Imager is an interactive image compressor. It provides real-time preview of compressed image and handy means to compare it with original one. You can fiddle with various compression parameters and observe the effect of changes straight away. You also can specify a desired file size and let the program select the proper values automatically. It is perfect for “Quality vs. File Size” optimization.
JPEG Enhancer Rate This product fixes artifacts and defects in your JPEG images.
Version 1.0 shipped in December, 2003.
PICPress Rate An image conversion program that does smoothing of JPEG images.
JPEG-2000

RomSoft JPEG2000 libraries and plugins Rate
JPEG200 products provided by RomSoft. Here you find a C++ DLL implementation of JPEG2000 Part 1 standard (ISO/IEC 15444-1) and a Photoshop plugin for JPEG2000 and J2K files
Reader Petrut D. had this to say:
One of the fastest JPEG2000 codecs out there. The Intel IPP library helped a lot with performance. I also tried the Photoshop plug-in, and managed to open all the test files from http://www.crc.ricoh.com/~gormish/jpeg2000conformance/J2KP4files/ part 0 and part 1. The plug-in handled JP2 and J2K images from 1 bit to 16 bit signed/unsigned flowlessly. Highly recomend the C++ DLL and the Photoshop plugin.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
LEADTOOLS JPEG2000 Plugin Rate LEADTOOLS is now supporting JPEG2000 in their toolkits by means of this JPEG2000 plugin. Supports both file and stream formats, plus many additional features. Download of sample available.
AMC-JPEG2000 Rate This product converts your photos to JPEG-2000 format to speed up the process of sending them by mail. And how do your friends view these photos when they get them? Well, it appears that AMC will be happy to give them a free JPEG 2000 viewer.
PhotoNav Rate PhotoNav is a commercial optimized mega-image navigator system based on JPEG-2000. An alpha version of the PhotoNav client is now available for Palm handhelds. This software lets you browse JPEG-2000 images on your PDA.
JPEG 2000 Project Related Links Rate Links to several projects that are working with JPEG 2000 technology.
SouthDowns Rate SouthDowns is a set of Perl scripts for the creation of JPEG 2000 files from JPEG 2000 codestreams. If you’re interested in the format used by the standard, this might be an easy way to experiment with it. The sample program appears to insert some metadata into the image file.
Warning: this release has no release information and no licensing information!
Lossless Compression

RICAZip.com Rate
RICAZip.com has proprietary lossless image compression technology called RICA (Reversible Image Compression Algorithm). RICA retains original file formats (e.g. TIFF, DICOM, BMP, TGA, PGM etc.). RICACom says We have yet to find any method that provides better compression ratios (for truly lossless), including wavelet. On a PII 450MHz RICA compresses @ 6MB per second and decompresses at 12MB per second.
Available as a standalone image archive app, Adobe Photoshop Plugin, Browser Plugin, and RICA SDK.
DCL reader Karen H. says: Evaluation of this product demonstates excellent compression ratios and it is also very fast compared to other methods I have used.
SoftDefender Rate
Soft Defender is a good exe file compressor, which can reduce the file size of 32-bit Windows programs by as much as 50%.In addition, Soft Defender is a perfect product of software protection of applications.With Soft Defender, your application can have anti-debugging, anti-tracer, anti-disassemble, anti-dumping, anti-apihook, file integrity checking functions in seconds. It requires no source code editing or your registration algorithm changing.
X-PRESS Rate
A Multiplatform data compression program, looks like it runs on a wide variety of IBM mini and mainframes. Company has a dual-language web site, with English and German language versions.
Data Compression Program for VM/ESA Rate
DATA COMPRESSION PROGRAM for VM/ESA enables VM customers to automatially (sic) and transparently compress and expand CMS minidisk file data. This capability can help reduce DASD utilization, load on the I/O subsystem, and staff time spent managing minidisk space and “disk full” conditions.
From your friends at IBM.

Telvox Software Shop Rate
This site has links to Telvox’s CODEC package, which appears to ship in both free and commercial versions. CODEC uses proprietary lossless compression, and is ported to a wide variety of platforms. Telvox is located in Bologna, Italy, and has duplicate web pages in English and Italian.
MoleBox Rate Pack all your files into a single executable with MoleBox or MoleBox Pro.
Solution-Soft Rate Solution-Soft is the provider of software for online archiving and for bandwidth management in the Internet infrastructure and the enterprise. Solution-Soft’s products enable data files to be archived online and transferred faster over networks through a revolutionary technology providing transparent compression and decompression.
The Official daxaif Home Page Rate From the site: daxaif is a no-loss audio compression program which performs live capture or converts audio files, movie sound tracks, or audio CD tracks into a compressed “.dax” file format. This format allows fast locating and selection of audio passages through the use of a clickable compression-factor map. The selections can be played or saved in uncompressed AIFF or further compressed to AIFC format using any QuickTime-supported compresser. .
limes datentechnik® gmbh Rate These folks deliver a tool called FLAM which uses a patented data compression algorithm to do something. The site has English and German language versions, but doesn’t seem to have any detailed information on FLAM.
MediaZip Rate MediaZip is a Windows program that performs lossless compression/decompression and manages archives of media files (Sound and Picture). Welcome to the MediaZip home page.
ServerZip Rate Stonebroom makes a product called ServerZip that compresses ASP web pages for quicker download.
MaX Compression Rate This product compresses email before transmission to save network bandwidth.
GT Technology Rate This site advertises a bunch of nifty looking codecs, including TELP, JPEG, Speech, MPEG, and wavelet compressors. I can’t quite determine exactly what form the products come in.
PipeBoost Rate PipeBoost offers HTTP Compression software that comes with a big list of customers and testimonials. You can download a 30 day trial copy, so you have nothing to lose!
BrowseBlast Web Accelerator Rate The press release says: Ikano and SlipStream launched the BrowseBlast Internet service for U.S. consumers. SlipStream’s Web Accelerator is supposed to increase connection speed significantly for dial-up and wireless connections. The software compresses Web content once it leaves the server, increasing browsing speeds to five times the traditional dial-up or wireless speed.
MP3/MPEG Audio

RealNetworks MPEG Encoder (was Xing) Rate
Xing’s encoder creates both audio and video MPEG streams.
Media Digitalizer Rate
This appears to be a tool that is designed to aid you in the process of digitizing your LPs and cassettes to your PC. It will export to MP3 format, which explains its presence here.
Xing AudioCatalyst Rate
AudioCatalyst is a commercial program that creates and playsback MP3 files. The recorder can rip tracks from music CDs and convert them to MP3 files in many different formats. A trial edition of the product is available at this web site.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
Advanced MP3 Converter Rate This conversion tool will convert between several audio formats, including WAV, OGG, and MP3. Supports ID3V1 and V2, plus other goodies.
ADI MPEG Audio Player Rate A plugin for the Netscape browser that lets you listen to MPEG audio streams.
WMA MP3 Recorder Rate WMA MP3 Recorder turns your computer into complete audio recording studio. You can record sound from any internal or external source into WMA/MP3 format sound file directly without use additional disk space.
Version 5.60 is shipping as of April, 2003
WMA To MP3 Converte Rate WMA To MP3 Converter was written for converting WMA to or from MP3/WAV files. So, with WMA to MP3 Converter, you may convert WMA to MP3, convert WMA to WAV, convert WAV to WMA, convert MP3 to WMA.
FairStars Recorder Rate This Win32 program is designed to work directly with your sound card, allowing you to record audio from virtually any source and any program. It makes it into DataCompression.info because it will encode directly to MP3 format.
Version 1.05 is shipping as of March, 2003.
Power WMA Recorder Rate Power WMA Recorder is a program that can create WMA files from any available sound source directly without using any additional disk space. In addition to supporting Microsoft’s WMA format (including the variable bit rate option), Power WMA Recorder can encode directly to MP3 format.
Version 1.34 is shipping in March, 2003.
Waver Multiprocessor WAV and MP3 converter Rate Waver is a program that can convert back and forth between MP3 and WAV formats, using the Blade and LAME MP3 codecs. This product’s claim to fame is its ability to soak up all the cycles on more than one CPU simultaneously. So if you’re lucky enough to have a multi-CPU MOBO, you can go to town with this commercial product. You get a 30-day free trial to decide if it’s worth the price.
i-Sound WMA/MP3 Recorder Professional Rate This app from AbyssMedia is advertised as being able to turn your computer into complete audio recording studio. That means you have the ability to record from external inputs directly to MP3, OGG, WMA, or WAV format. Includes niceties such as MP3 and OGG tag editors, Voice Activated recording, skin support, and more.
Version 6.05 is shipping in November, 2003.
Helix DNA Client Rate Real is making their client software available in an Open Source program. Download this software and you can develop your own MP3 player! Free of royalties if you are distributing it for free – commercial products pay a royalty.
MP3 Splitter & Joiner Rate An MP3 editor, lets you split and join MP3 files, as well as creating or modifying ID3 tags.
Version 2.40 shipped in April, 2003.
RIP Vinyl by Wieser Software Ltd Rate Ripping CDs to MP3 format is pretty easy – the CD format lets the ripping program know when one track ends and another beings. Not true for old-schoo vinyl records, and that’s where RIP Vinyl wants to make a difference. It attempts to partition your input into tracks by looking for the gap between songs. Naturally, it has many other options, and will record directly to MP3 format. The program gives you control over the level sampling begins at, and the minimum amount of time that must elapse between tracks, and can record from any audio source on your PC.
No version information seems to be available on the web site.
Visual Text To Speech MP3 Rate This product takes your text, converts it to speech, then stores the result in one of several compressed formats, including MP3, Ogg Vorbis, and G.721.
EXEmp3 Rate This program has a novel approach to the distribution of MP3 files. Instead of just shipping MP3 files around, the folks at EXEmp3 propose packaging the MP3 file with a mini-player executable, as well as a copy of the song’s lyrics. The player only takes up 48K under Windows, and you can unpack the original MP3 file if you like.
Version 1.3 is shipping as of March, 2003.
MPEG

RealNetworks MPEG Encoder (was Xing) Rate
Xing’s encoder creates both audio and video MPEG streams.
Elecard Rate
This company has a roster of compression products, including an MPEG-2 Player, an MPEG-2 DirectShow Filter, and a Wavelet Image Compressor.
DataCompression.info user Kuka had this to say: Excellent mpeg player, and a lot of very useful mpeg tools.
Optibase Rate
Optibase claims to be a leading supplier of MPEG content creation tools. Their Web site lists products such as MPEG ComMotion Pro and the The MPEG ComMotion UDP.
UB Video, Inc. Rate
UB Video says: UB Video Inc., based in Vancouver, Canada, is a leading provider of coding and transcoding software solutions for video communications. UB Video provides software products that run on desktop PCs as well as on programmable Digital Signal Processors and Media Processors. UB Video’s products include:
Encoders/Decoders
H.261 (Libraries/Source code)
H.263/H.263+ (Libraries/Source code, Encoder/Decoder DirectShow filters, Video for Windows codecs, Java decoder)
MPEG-4 (Libraries/Source code)
MPEG-2 (Libraries/Source code) Transcoders
H.263 to H.261 and H.261 to H.263 (Libraries)
MPEG-2 to MPEG-4 (Libraries) Free demos of the H.263+ codec (UB-Live) and MPEG-4 codec (UB-Stream) can be downloaded from the web site.
Ligos Technology Rate
Ligos claims to have the world’s best MPEG-2 encoders. The products are part of the LSX-MPEG family. Take your pick and purchase directly from the web site.
PixelTools – the MPEG Experts Rate
MPEG encoders and decoders, authoring software, and libraries.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
iVAST Rate This company labels itself as “The world leader in end-to-end MPEG-4 Solutions.” Looks like they sell a suite of authoring and encoding tools, and perhaps some server software. Follow the link to “About MPEG-4″ and you’ll get a little bit of text plus some more links.
LSI Logic / C-Cube Microsystems. Rate C-Cube makes hardware and software encoder and decoders for MPEG video and audio.
C-Cube was engulfed by LSI Logic in 2001, you can now find all of their products here, probably under Professional Codecs and Consumer Products.
Hyper MPEG Player Rate A Netscape plug-in that lets you display MPEG files online. Avoid the hassle of requiring a complete download before you can start viewing the file.
InterVU MPEG Player Plug-in Rate A browser plug-in for Netscape that lets you view streaming MPEG.
Download mtv for Linux & Unix Rate mtv is an MPEG TV Player that runs under Linux and UNIX. Besides watching MPEG files from the Interneti, mtv also lets you play Video DVDs. Freeware and commercial versions are available.
Philips MP4Net Rate Philips MP4Net web site is here to tell you abou the WebCine line of products, which includes an MPEG-4 Encoder, Server, and Player. It looks like the player is yours for the asking. Other links here explain MPEG-4, as well as offering you careers with Philips.
imageEnhance Rate This product from Teranex removes DCT blocking artifacts from MPEG streams. It also features a few other neat details such as adding the “film look” to digital video.
IBM Toolkit for MPEG-4 Rate The IBM Toolkit for MPEG-4 consists of a set of JavaTM classes and APIs with five sample applications: three cross-platform playback applications and two tools for generating MPEG-4 content for use with MPEG-4-compliant devices. These applications are as follows:
AVgen: a simple, easy-to-use GUI tool for creating audio/video-only content for ISMA- or 3GPP-compliant devices
XMTBatch: a tool for creating rich MPEG-4 content beyond simple audio and video
M4Play: an MPEG-4 client playback application
M4Applet for ISMA: a Java player applet for ISMA-compliant content
M4Applet for HTTP: a Java applet for MPEG-4 content played back over HTTP.
AVI to MPEG Converter Rate This Win32 program will convert your AVI files to various MPEG file types. There is a free version which limits conversions to MPEG-1. The commercial version supports MPEG-2 and various extensions.
Precision Digital Images Rate This company makes digital video streaming hardware and software. Although it looks like maybe they don’t actually make the hardware, they help you design it.
GT Technology Rate This site advertises a bunch of nifty looking codecs, including TELP, JPEG, Speech, MPEG, and wavelet compressors. I can’t quite determine exactly what form the products come in.
Vprove from Vqual Rate Vprove is a PC-based software package that analyzes video streams. It is intended as a way for developers to optimize their compressors, doing such things as analysis of motion estimation and image clarity. The product works with H.261, H.263, and MPEG-4 streams. This is a sophisticated product with many interesting features, if you are a content creator or develop content creation tools, you need to check it out.
VECTAR Rate V.E.C.T.A.R. (Video Enhanced Compression for Transmission and Recording) is a high performance video and stereo audio encoder that delivers multimedia content of unprecedented quality across standard broadband and unsurpassed quality across restricted bandwidth. This PCI encoder encodes full motion analog video and stereo audio, and multiplexes it to the system stream to ensure 100% synchronized delivery. Cyber Operations’ patent pending MPEG-X is the groundbreaking technology that makes V.E.C.T.A.R. unique. MPEG-X incorporates MPEG-1, MPEG-2, and MPEG-4 compatibility, and allows V.E.C.T.A.R. to provide higher quality compressed video than any other available technology.
Dr. DivX Rate DivXNetworks offers this product which lets you create DivX streams from video in quite a few other sources. They’ve included an MPEG-2 decoder, so you are able to convert DVD content to the new format and save some serious space.
WinMPG Video Convert Rate This is another Swiss-Army Knife converter, letting you move back and forth between AVI, MPEG-1, MPEG-2, DivX, and SVCD formats.
Version 2.5 is shipping as of April, 2003.
PNG

Image Viewers with PNG Support Rate
Tons of links to software here
Applications with PNG Support Rate
Just what it says.
2PNG Rate 2PNG is a graphics converter allowing you to convert images to png format from 50+ image file types including conversions from jpeg to png, from gif to png, from tiff to png and so on. (See the full list of supported formats here.) The program has no windows interface and is fully optimized for working in background mode
PNG/MNG Construction Set Rate PNG/MNG Construction Set represents the state of the art in animation software. It will assemble your original animations effortlessly through its Animation Wizard, squeeze them down to as close to nothing as possible with its Supercompressor; create eyecatching banners and animated transitions; manage your MNG files; add transparency to existing PNG graphics and a lot more.
Version 2.0.25 is shipping as of June, 2004.
PPM

ShipInBottle Archiver Rate
This is a Russian language web site, so I’ll have to apologize in advance for any mistakes. As far as I can tell, this is a PPM-based archiver. I can’t tell if it’s free or not, so I’m listing it as both!
Quantization

TwinVQ Rate
An audio compression format invented at NTT’s Cyber Space Laboratories. Get your player and compressor right here. (English avaible by following the sharp-eyed link.)
Self Extractors/Executable Packers

FileStream, Inc Rate
FileStream makes quite a few compression-related programs, including TurboZip and TurboSFX. Release 5.,1 appears to have shipped sometime in the latter part of 2002.
ASPack – an Executable Compressor Rate
Another program for compression executables. This is a Win32 preprocessor that claims to reduce EXE size as much as 70%.
Advanced Zip Repairer Version: 1.20 Rate
Advanced Zip Repairer(AZR) is a powerful tool to repair corrupted Zip files and Self Extracting files(SFX). It can recover your data in zip archives as much as possible, so to minimize the loss in file corruption. Currently AZR can fix all sub-types of zip files and all kinds of self-extracting files, also it will provide a tiny exe stub when repairing SFX files. Moreover, it has integrated with windows shell and supported drag & drop operations, which will make you repair files easily and quickly.
PKWAre Self Extractor (SFX) and Secure Data Distribution Licenses Rate PKWare lets you create secure SFX files for distributing data. However, they aren’t going to tell you how much you have to pay on this page – you have to fill out an inquiry form and send it to their sales team.
SFX Creator Rate This program creates a very high secure AES /Serpent/Twofish 256 bit/Blowfish 448 Bit, Mars 1248 Bit and RC6 2048 Bit selfextracting file. The SFX-Header is 41kb-49kb great. This SFX cipher checks whether the decrypting password is correct with a highly secure method, never compromising the key: while a 64 byte random number is created and also encrypted. While decrypting these two numbers are compared to test for the correctness of the password. Very simple, yet as safe as the algorithm itself. The license covers Multicrypt too. One license for two programs.
PECompact Rate PECompact compresses Windows executables significantly, while allowing them to be run as normal. You can compresses code, data, import/export table, and selected resources. Section merging and resource data restructuring are also supported. It trims, optimizes, and realigns the PE structure while preserving shell icons and version information, or any other resources you chose to leave uncompressed. Uses its own JCALG1 compression, which offers decent compression speed, great compression ratio, and extremely rapid decompression.
Version 2.28 is shipping in June, 2004.
Petite Win32 Executable Compressor Rate Petite is a Win32 (Windows 95/98/2000/NT/XP) executable (EXE/DLL/etc…) compressor. The compressed executables decompress themselves at run time, and can be used just like the original uncompressed versions. Petite also adds virus detection to the compressed executables – they will check themselves for infection every time they are executed.
Smart SFX Rate This tool creates SFXs for your archives, and currently has both 16- and 32-bit extractor modules. Includes advanced features such as SFX files that span multiple disks. Commercial Windows software.
Version 3.0 is shipping as of February, 2003.
Planet Zip Suite Rate Another Win32 archiving program, supporting the Zip format and scads of others, as well as providing SFX, encryption, a file splitter, and best of all, a free world clock!
JDPACK Rate This is reportedly a Win32 exe packer. However, this is a Chinese langauge site so even that is just a guess.
PeX home page Rate This is reputedly the home page of the PeX executable cracker. However, the fact that the page appears to be in Polish keeps me from saying more than that.
Advanced Zip Repair Rate Advanced Zip Repair(AZR) is a powerful tool to repair corrupted Zip and self-extracting(SFX) files. It can recover your data in Zip archives as much as possible, so to minimize the loss in file corruption.
Version 1.6 is shipping in May, 2003.
Zipbit Rate Zipbit is yet another inexpensive Win32 archiver with support for a wide range of archive types. Creates SFX files, integrates with Windows Explorer, and has localized versions for English, German, and Russian.
Version 1.05 is shipping as of April, 2003.
Zip Assistant Rate Zip Assistant is a vanilla Win32 archive program, which appears to be slanted towards the novice user who might need a bit of handholding. The web page does say that advanced users will appreciate some features as well, and the feature list does include disk spanning, SFX files, and more.
Version 4.6 is shipping as of April, 2003.
Speech

Digital Voice Systems Inc. Rate
This company makes the AMBE-2000, a Vocoder chip that compresses speech down to a miniscule 4 Kbps. They have an additional product library of low bit-rate codes both in hardware and software.
TrueSpeech Rate
The DSP Group makes a codec called TrueSpeech. You can get a copy of the player for free here to check out the 8.5 KBps audio it makes possible.
GT Technology Rate This site advertises a bunch of nifty looking codecs, including TELP, JPEG, Speech, MPEG, and wavelet compressors. I can’t quite determine exactly what form the products come in.
Visual Text To Speech MP3 Rate This product takes your text, converts it to speech, then stores the result in one of several compressed formats, including MP3, Ogg Vorbis, and G.721.
Video

RealNetworks Rate
Makers of lots of audio and video compression stuff.
VisioWave Rate
VisioWave is offering simple, modular, integrated and open-ended high-quality and reliable hardware and software solutions for compression, processing and real-time transmission of very high quality video over any network (IP, ATM, ADSL, cable, wireless, …).
All Codecs and Decompressors Rate
This site appears to have a wide variety of video codecs for popular desktop operating systems.
Blaze MediaConvert Rate
This product performs a huge number of conversions among different media types. Want to convert your huge collection of MP3 files to WMA? No problem. MPEG-2 to AVI? No problem. MediaConvert even handles some unusal conversions, such as video to animated GIF. And naturally, a huge number of conversions between various image formats, including GIF, JPG, PNG, and a host of additional types.
Release 2.3 shipped in Julyy, 2003.
Streambox Action Rate
Streambox ACTION is an easy to use video encoding application for serious amateurs and webmasters. ACTION goes beyond simple “file save” routines in video editors, allowing you to interactively optimize your video for specific streaming data rates while preserving video quality. ACTION is specifically designed to produce output optimized for the best progressive download/streaming video player on the market, Apple QuickTime. Convert any DV, AVI. or MOV file into a high quality .MOV file for playing on any QuickTime Player, available for free from Apple.
Reader John G. says Good video codec.
Windows Media 9 Series Rate
Microsoft’s web page for all things releated to the new Windows Media Player and more. At this time you can download the beta version of the new player, get information, and sample various media.
Reader Serg N. commented: Very good quality, support for [very] low bitrates, lossless mode. It’s not open source, but it’s free!
UB Video, Inc. Rate
UB Video says: UB Video Inc., based in Vancouver, Canada, is a leading provider of coding and transcoding software solutions for video communications. UB Video provides software products that run on desktop PCs as well as on programmable Digital Signal Processors and Media Processors. UB Video’s products include:
Encoders/Decoders
H.261 (Libraries/Source code)
H.263/H.263+ (Libraries/Source code, Encoder/Decoder DirectShow filters, Video for Windows codecs, Java decoder)
MPEG-4 (Libraries/Source code)
MPEG-2 (Libraries/Source code) Transcoders
H.263 to H.261 and H.261 to H.263 (Libraries)
MPEG-2 to MPEG-4 (Libraries) Free demos of the H.263+ codec (UB-Live) and MPEG-4 codec (UB-Stream) can be downloaded from the web site.
Clipstream 2.0 Rate
Clipstream is a product that compresses audio to either 20Kbps or 32 Kpbs, depending on the speed of the connection. A java applet on a web page is used to decode the stream and play it over the sound card of the target computer. The web site has demos of several types of sound. Update: Clipstream has java applets for both video and audio!
Motion-JPEG CODEC Rate
MainConcept makes a codec that encodes things in the Motion-JPEG format.
MediaOne+ Rate A relatively standard Windows media player. Handles DVD, MP3, DivX, etc.
ACDZip Rate ACDZip is a zipping and unzipping program that gives you the power to compress image, audio, video and document files. It includes fast image previews and is ideal for opening zip files, backing up files, saving hard disk space, preparing files for distribution and protecting them with encryption and passwords.
Windows Media 9 Final Release Rate This page has links to download all the various components of Windows Media 9, including the media player, codecs, encoders, embedded toolkits, and more.
The Official daxaif Home Page Rate From the site: daxaif is a no-loss audio compression program which performs live capture or converts audio files, movie sound tracks, or audio CD tracks into a compressed “.dax” file format. This format allows fast locating and selection of audio passages through the use of a clickable compression-factor map. The selections can be played or saved in uncompressed AIFF or further compressed to AIFC format using any QuickTime-supported compresser. .
JPGAvi Rate JPGAvi is used to create a video file, with an optional sound track, from either a series or a single bitmap file.
Shareware version 1.05.1.4 was shipping in January, 2004.
Precision Digital Images Rate This company makes digital video streaming hardware and software. Although it looks like maybe they don’t actually make the hardware, they help you design it.
Compression Technologies, Inc. Rate These folks make CinePak and CinePak Pro, which are digital compression tools based on the CinePak codec. They have applications that run on both MacOs and Windows.
Motion Pixels Company Rate These folks make a product called MP Studio Pro, which is a compression/decompression engine, and seems to be geared towards content producers.
Quicktime Rate Apple’s Quicktime page. Get it here.
CyberMail Rate Cybermail is a product that lets you compress video files for email transmission. According to the advert, they have a revolutionary new compression engine!,
Zoom Player Rate A media player that comes in a free and pay version. Although it’s labeled as a media player, it looks to me as though this is primarily inteded to be used as a DVD player.
Ace Media Player Rate Ace Media Player supports an impressive list of media types, including Real, MPEG, DivX, QuickTime, VCD, WMF, and of course, MP3. This is a commercial product, but you can get a 30 day eval copy.
Version 2.2 of Ace Media Player shipped in March of 2003.
Vprove from Vqual Rate Vprove is a PC-based software package that analyzes video streams. It is intended as a way for developers to optimize their compressors, doing such things as analysis of motion estimation and image clarity. The product works with H.261, H.263, and MPEG-4 streams. This is a sophisticated product with many interesting features, if you are a content creator or develop content creation tools, you need to check it out.
EasyX Video Converter Rate This shareware Win32 program can convert video files between various formats, including MPEG-1, MPEG-2, MPEG w/VCD extensions, and more.
Version 1.10 is shipping as of April, 2003.
Helix DNA Client Rate Real is making their client software available in an Open Source program. Download this software and you can develop your own MP3 player! Free of royalties if you are distributing it for free – commercial products pay a royalty.
DVD Boy Player Rate Your basic Windows media player. DVD Boy Player plays DVDs as well as SVCD, DivX, and MPEG-4 files.
Version 2.1 is shipping as of April, 2003.
Windows Media® ASF Viewer 9 Series Rate Microsoft supplies this free tool as a way for developers to check their files for validity before shipping. Looks like it knows how to inspect ASF, WMA, and WMV files.
Windows Media Diagnostic Tool Rate Having trouble with your Windows Media Player? This program gathers up all your information and stores it in a compressed file that you can quickly mail to your tech support pal in Redmond.
Windows Media 9 Authoring Utilities Rate Creating Audio and Video content with Windows Media 9 is made possible by the authoring tools listed on this page. At the time this is entered, the list of tools includes:
Lossless to PCM Converter
Mono to Multichannel Wave Combiner
Video Compression Manager
Plug-in for Adobe Premiere 6.5
Windows Media 9 Capture
Windows Media Video 9 VCM Rate The Video Compression Manager is an add-on from Microsoft that will allow older apps that use AVI containers to use WMA 9 codecs.
Welcome to Advanced RealMedia Repair Homepage Rate Advanced RealMedia Repair is a package that will help you repair your broken RealMedia files. Supports both video and audio files.
WinMPG Video Convert Rate This is another Swiss-Army Knife converter, letting you move back and forth between AVI, MPEG-1, MPEG-2, DivX, and SVCD formats.
Version 2.5 is shipping as of April, 2003.
Media Wizard Rate Description from the web site: Media Wizard is a powerful, all-in-one multimedia application supporting playback of all popular formats, audio and video conversions (CD to WAV; CD to MP3; CD to WMA; CD to OGG, WAV to MP3; MP3 to WAV; WAV/MP3 to WMA; WMA to WAV/MP3; WAV/MP3 to OGG; OGG to WAV/MP3; WAV/MP3 to CD; AVI to MPG; MPG to AVI; etc.)
This is a Win32 program, and version 8.0 is shipping as of April, 2003.
AVI-GIF Rate This is a batch image converter that lets you go back and forth between AVI and GIF. I don’t know what the practical limits are on the size of animated GIF files, but I’ve seen some pretty cool short videos in the format. This looks to be the way to create them.
Release 1.09 shipped on July 15, 2002.
All Converter Rate Yet another conversion program: All Converter is a powerful, all-in-one, multimedia application converting the media files among the most popular media formats.With All Converter,you can convert MP3 to WAV,MP3 to WMA ,MP3 to OGG,MP3 to VQF, WAV to MP3,WAV to WMA,WAV to OGG,WAV to VQF,WMA to MP3, WMA to OGG,WMA to VQF,OGG to MP3,OGG to WAV,OGG to WMA,OGG to VQF,VQF to MP3,VQF to WAV,VQF to WMA,VQF to OGG, normalize files,and support ID3 tag v1, v2 to file name conversion and vice versa.
Easy Video Joiner Rate This commercial program is used to join multiple video files into a single file. Supported video formats include MPEG, RM, and Windows Media.
Version 5.01 shipped in March, 2003.
Wavelets

Elecard Rate
This company has a roster of compression products, including an MPEG-2 Player, an MPEG-2 DirectShow Filter, and a Wavelet Image Compressor.
DataCompression.info user Kuka had this to say: Excellent mpeg player, and a lot of very useful mpeg tools.
VisioWave Rate
VisioWave is offering simple, modular, integrated and open-ended high-quality and reliable hardware and software solutions for compression, processing and real-time transmission of very high quality video over any network (IP, ATM, ADSL, cable, wireless, …).
ECW Compress by Earth Etc. Rate
Earth Etc. makes a free wavelet based compressor that somehow ties in with their web server product. In theory they supply plugins that you can use to view the compressed images.
DCL reader JJB had this to say: Limited in size and other features in the free version as well as limited documentation in the free version, but decent examples if you can learn from those (you just can’t learn what they don’t show there). Very specific to Geo-Spacial images (satelite images and the like), decent compression, speed and recovery of all sizes equal to or less than original (use power of 2 sizes for best results)..
MT-WICE® – Wavelet based image compression Rate
A proprietary image compression system using wavelets by MeVis Technology. Browser plug-ins available, naturally. Links to German language version of the page.
A DCL reader had this to say: Achieves high compression and has a useful interface. I have used only the non-registered version 2.6e very powerful and probably superior to JWizard by Pegasus.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
http://www.barrt.ru/parshukov/imcomp.htm Rate A shareware image compression program that supports a ton of different formats.
Wavelet2000 Streaming Video Rate A streaming video codec designed as a DirectShow filter.
Compression Engines, Inc. Rate Compression Engines, Inc. has a file format called WIF, which stands for Wavelet Image Format. They licensed it from HARC, and have created and ActiveX control, a browser plugin, a standalone program, and the requisite Photoshop plugin. Check it out.
GT Technology Rate This site advertises a bunch of nifty looking codecs, including TELP, JPEG, Speech, MPEG, and wavelet compressors. I can’t quite determine exactly what form the products come in.
Zip

Absolute Packager from Xceed Software Inc Easily create sharp-looking, feature-rich Self-Extracting (.EXE) Zip files with this handy desktop application. Lets you quickly select a group of files to zip up and put into a .EXE file. Even supports being able to split the .EXEs across multiple floppy disks.
DWG2ZIP Rate
This program lets you compress AutoCad DWG files into Zip archives for distribution.
Version 2.0 is shipping as of May, 2003.
FlyZip Rate
FlyZip is a compressor designed to help you save space on your Palm O/S device, including Palm-based phones.
FlyZip XR 3.02 shipped in December, 2003.
PentaZip Rate
PentaZip has a very nice feature set, supports advanced encryption, large archives, Windows shell integration, and all the other good stuff you’ve come to expect. Also supports a wide variety of languages.
Release 6.0.1.190 shipped in November, 2003
PKZIP Explorer Rate
PKZIP integrated with Windows Explorer. Zip and Unzip through easy menu options.
BitZipper Rate
Another Win32 archiver that can work with a zillion formats. Recent new features added to BitZipper include deflate64 support, ACE archive support, and better integration with the Windows shell.
BitZipper 4.0 shipped in February, 2004.
EzZip Suitcase Rate
This product bills itself as the “Ultimate Multilingual User Friendly” compression tool. The usual Zip features plus support for six different languages. Fifteen day free trial download.
Reader Donald J. says Excellent zip utility and definitely the easiest I have ever used.
1st Choice Zip Rate
A shareware program that uses the look and feel of Windows Explorer to navigate Zip files.
Version 4.7 of this program is shipping as of November, 2003.
CCZip Rate
Another zip utility.
UUNet FTP Site Rate
This ftp site has copies of Zoo, ARC, gzip, and zip, in some cases for multiple platforms.
ZFilter Rate
ZFilter is the ZIP indexing filter for SharePoint, Internet Information Server, Site Server and Microsoft Exchange server. ZFilter is a library that handles .zip archives and returns indexable text and value properties in a similar way to the MS Office filter and the PDF filter supplied by Adobe. The library handles all zip archives created with WinZip, PKWare and DynaZip, indeed any archive created using the compression format based on PKWare.
Satisfied DataCompression.info user Jim R. had this to say:I’ve been searching high and low for exactly this thing for years, and now I’ve found it, and it works.
CHAOS Self Extractor Rate
CHAOS Self-Extractor is a utility program that creates self-extracting ZIP files for Windows. CHAOS supports a form of encryption that it claims is much stronger than standard Zip encryption.
Password recovery software Rate
Elcom makes password recovery software, which includes support for Zip and Arj files.
WinZip Computing Rate
The home page for WinZip Computing, makers of WinZip. WinZip is a very popular Win32 Zip program. This page has links to an evaluation version of the program available for download, plus an FAQ, and other online support.
WinZip 9.0 shipped in February, 2004. Highlights include AES encryption and 64-bit Zip format support.
PillarSoft Rate
Want a version of zip for OS/2? This is the place to get it. WarpZip is built on the Infozip software.
Netzip 7.5 Rate
The family of Netzip archiving programs seem to have a good set of features and have received good reviews when compared to WinZip and PKZip for Windows. NetZip 7.5 adds some flashy new features, including skins!
Hack Systems Rate
Hack Systems makes DataSafe, a product that backs up files using Zip format.
PKWare problems with PKZIP 2.0 Rate
During the development of PKZIP v. 2.0 for MS-DOS, PKWARE has discovered hardware faults in newer 80386 & 80486 computers. These faults can cause anomalies in the operation of PKWARE software as well as other software.
ChilkatZip Self-Extractor Rate ChilkatZip Self-Extractor is a utility program that creates self-extracting ZIP files for Windows 95/98/Me/NT/2000/XP. They advertise a few interesting features, including 256-bit encryption, streaming technology, and progress indicators.
ZipMagic Rate ZipMagic gives you transparent access to Zip files via the technology from the ZipFolders product. Treat archive files as if they were ordinary folders. ZipMagic of course contains a number of other nice features.
ZipSearch Rate A search program for Win32 computers. ZipSearch knows how to look through Zip files and compressed EXEs to find search strings.
Version 1.07 shipping in December, 2002.
WS:Compress Out Rate WS:Compress Out is a member of Websetters family of Microsoft Office Add-Ins. This Add-In extends the functionality of Microsoft Outlook 2000, 2002 and 2003. Every time you send an email that contains attachments, WS:Compress Out will automatically compress the attachment and resave in the mail item. This reduces the amount of storage used by you in your Outlook storage, reduces the time online and network bandwidth used, reduces the amount of storage used by your recipients – all saving you money.
ExpressZIP Rate ExpressZIP features all of the powerful ZIP tools you’ll ever need in an easy to use and attractive interface and comes complete with built-in Wizards to walk you through creating ZIP and EXE (self extracting) archives.
Version 4.0 shipped in September, 2003.
The Unzip Wizard Rate The folks at Softword Technology have this to say about their product: There are many unzipping software tools to unzip ZIP files, but the easiest and friendliest of them all is The Unzip Wizard! It appears that this product is aimed at providing the core functionality needed by novice users. Shareware.
Version 3.1.0 is shipping as of June, 2003.
Automatic File Archiver by JSPayne Rate An archive manager that has some built in functionality that helps you with your backup requirements. Automatic archiving in the trusty Zip format.
FileWrangler Rate Yet another file manager that knows how to work with GIF files.
ZipRecovery Rate ZipRecovery purports to be able to repair your corrupted Zip files. They don’t talk too much about the details on the site, but they offer a demo program, so you can get an evaluation without actually buying a copy.
Version 1.5 is shipping as of October, 2003.
PKWare, Inc. Rate PKWare’s site. PKWare is the vendor of PKZip.
OutlookZIP Rate The OutlookZIP it’s an Add-On for Microsoft® Outlook. It makes easy for you to compress the files that you attach to Microsoft® Outlook e-mail messages. OutlookZIP adds three buttons to Outlook toolbar making the usage simple easy. OutlookZIP works only with Outlook 2000, Outlook XP (2002), and Outlook 2003. It does not work with Outlook Express.
Ascent Solutions, Inc. Rate ASCENT SOLUTIONS Inc. PKZIP data compression software for MVS (mainframe), Windows (Netzip), VM, VSA, AS/400, UNIX, OS/2, DOS, VMS. All products are 100% cross-platform compatible.
SmartZip Rate SmartZip is a MacOS application designed to be the simplest and most efficient way to manage ZIP files. You can automatically compress files (or entire folders) by dragging them onto SmartZip and in the same way you can easily expand ZIP files.
123 Zip! Rate A shareware Zip program for Win32.
ZipIt 2.0 Rate ZipIt is a Macintosh program that zips and unzips archives in a format fully compatible with PKZip for the IBM and zip implementations on other systems.
Zip IT 1.0 Rate This product is apparently some sort of archiver, but no information is to be found on this page!
Adaron Zip Portal 1.56 Rate Yet another Zip/Archiving program tailored to the Win32 environment. Drag and Drop, XP-style icons, etc.
1StepUnzip Rate A shareware unzipper for Win32.
WebZIP Rate This commercial product will zip up entire web sites and download them to your PC. You can then view them off line, at your leisure.
Attachments Zip Compressor Rate This commercial product takes care of managing your attachments. It appears to do this transparently, so you don’t even have to think about zipping up a big attachment before sending.
LightNZip Rate LightNzip is a PalmOS system compression and decompression utility.
ZipScan Rate ZipScan performs a fast file search that looks inside Zip, CAB, RAR, JAR, and ACE archive files, including self-extracting archives. The search can also check a file’s size, look for a text string, and search a file’s version resource table.
JIMZip Rate JIMZip is an easy-to-use, yet powerful, zipping and unzipping interface for MacOS X. Using JIMZip you can compress your files with a simple drag to either the JIMZip dock icon, or dragging window. JIMZip is compatible with programs such as: WinZip, PowerArchiver, PKZip, ZipIt, Aladdin Expander, Stuffit DropZip, and more..
Version 1.42 is shipping as of May, 2004.
ZipSplitter Rate ZipSplitter is a Win32 program that does two things for you. First, it zips up a single file. Second, it will split that zip file into several pieces of a size of your choosing. When it does this, the last chunk is an EXE file that knows how to recombine all the files into one.
Zip-I-Mage Rate This archiver is built specifically for support of image archiving. Supports popular formats such as JPG and BMP.
eZip Wizard Rate This Win32 archiver is free if all you ever do is unzip files. Creating Zip files is going to require registration and you coughing up a few bucks.
4Zip Zip Manager Rate This Zip file manager seems to be making its claim to commercial success on two factors. First, it’s 10 bucks cheaper than the big two, PKZip and WinZip. Second, it automatically fixes corrupt archives. (Although I’d love to see a discussion of just how well it does this.)
SimplyZip Rate Does everything you want, and costs a lot less than the two market leaders!
Version 3.0 is shipping as of June, 2004.
ZipWiz Rate This program by Synaptek Software is yet another zip program. Let me know if you find any distinguishing features of this release.
Plain Simple Zip 1.0 Rate A cheap shareware program that performs your basic Zip and Unzip functions.
ZipWrangler Rate Another Win32 archving program. The pgogram is free if you are willing to view ads, o/w $12.
Multi-ZIP-licity v1.5 Rate A zip program that lets you unzip a whole batch of files all at once.
Aladdin Dropstuff Rate Another product from Aladdin, makers of the world-famouse Stuffit program for the Mac. DropStuff comes in versions for the Mac and Windows, and will store archives in either Zip or Sit formats.
Data21.com Rate Data21.com makes versions of PKZip for various IBM environments, including VM and AS/400.
Plain Simple Zip Rate Just what the name says, a very simple Zip program for Win32. Registration is $10.
Advanced Zip Repair Rate Advanced Zip Repair(AZR) is a powerful tool to repair corrupted Zip and self-extracting(SFX) files. It can recover your data in Zip archives as much as possible, so to minimize the loss in file corruption.
Version 1.6 is shipping in May, 2003.
SuperZip Rate A full-featured release of a Win32 Zip program. Version 3.0 was released in October, 2002. Trial version available.
PKZIP Rate PKWare’s page for PKZip. Currently offering four flavors of PKZip for Windows, and a big mess of versions for UNIX.
Version 6.0 of PKZip appears of have shipped in January of 2003.
AutoZip Rate AutoZIP Backup is professional software that lets you automate the backup of your precious files to a ZIP archive.
Version 1.0 of this product is shipping as of April, 2004.
12Ghosts Zip Rate This package includes 12Zip and 12Zip2. The first version uses Zip compatible compression, and the second uses a BWT variant.
Version 7.0 of the package is shipping as of May, 2004
DropZip by Aladdin Systems Rate A commercial program that supports both the Stuffit and Zip formats. DropZip is available for both Mac and Windows platforms.
ZipForward Rate This program appears to be a decompressor only – it lets you look at the contents of a Zip file, but doesn’t give you a way to manipulate the contents. It offers the ability to preview files from inside the Zip file, and has a mysterious feature that I don’t understand:
ZipForwardâ„¢ can burn your package to an Application (.EXE) format. This means that anyone with a Windows computer can run and extract your package, just by double-clicking the icon. From then on they can use the package you gave them to send to their friends, and their friends, and so on.

ZipForward 1.1 is shipping as of April, 2003.
Zip Assistant Rate Zip Assistant is a vanilla Win32 archive program, which appears to be slanted towards the novice user who might need a bit of handholding. The web page does say that advanced users will appreciate some features as well, and the feature list does include disk spanning, SFX files, and more.
Version 4.6 is shipping as of April, 2003.
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Companies/Organizations

Companies and organizations. The name for this category should give you all the explanation you need.
Archiving

DC Micro Home page for DC Micro, home of Crusher!, the data compression toolkit
Xceed Software, Inc. Makers of high-quality, commercial-grade data compression, encryption and internet components for Windows developers.
AIPNL data compression pages Rate
Information on: UC2 ARC ARJ LZH RAR ZIP UCRYPT JPEG MPEG etc. I think AIPNL makes UltraCompressor.
Greenleaf Software Rate Greenleaf sells ArchiveLib, an archiving library that supports both Zip and a proprietary format
Aladdin Systems, Inc. Rate Aladdin makes quite a few different software products, but the one we are concerned with is Stuffit, probably the best known archiver for the Macintosh platform.
Official RAR/WinRAR Registration and Support Site Rate I guess this is where you go to register or get support for your copy of RAR or WinRAR.
ARJ

ARJ Software, Inc. Rate The home page for Robert Jung and ARJ. This page has links to the ARJ FAQ, downloads of the various ARJ executables, and ordering information. It also is the home page for the newer JAR archiver. Arj is now on release 2.71.
Audio

Nellymoser Rate
Nellymoser is the leading provider of proprietary speech and audio software technology and solutions in the areas of compression, modification, synchronization and conversion. Our products improve speech and audio quality and efficiency in bandwidth-constrained environments while creating more immersive, interactive environments for your applications and services.
Vorbis.com Rate
One of the home pages of the Ogg Vorbis project, this is a good place to start if you’re looking for downloads, documentation, or Ogg Vorbis software.
SoftSound Rate
SoftSound deals with all aspects of processing the digital audio signal. We build audio coders to drastically reduce the data rate of high quality audio and speech coders for extremely low bandwidth situations. SoftSound produces the Shorten and ATELP audio coders.
IETF AVT Working Group Rate
This is the home page for the IETF group that reviews RTP packetization standards. Links on this page for all the drafts you can imagine for sending video and audio over RTP streams.
Philips – Business Team Sound Coding Rate
Historically, the BTSC has been involved in MPEG Audio from the very start. This site provides some background information on the various MPEG Audio standards.
This site provides some info on the background of MPEG, plus a couple of links to standards and so on.

Indeo Rate What was once Intel’s software now belongs to Ligos Technology. This is the home page for downloads, documentation, support, etc.
DAKX LLC Home Page Rate DAKX is claiming a new method of lossless data compression that is fast and patented. It works on audio and video data. The method is called difference-adaptive compression. DAKX supplies a bit of source code that you can experiment with, and will be happy to license the technology to you or your company.
ACM Multimedia 2002 Rate The ACM Multimedia conference for 2002 takes place December 1-6, 2002 in beautiful Juan-les-Pins on the French Riviera. Get your submissions in quick before the show fills up.
RealNetworks Helix Initiative Rate RealNetworks has announced that they are going to be Open Sourcing a significant portion of their server products. Outlook from the Open Source community is guardedly optimistic.
Coding Technologies Rate These guys are responsible for some of the work that took the MP3 standard to its next revision: MP3Pro. They say their current focus is the development and marketing of SBR-enhanced codecs.
Scala Technology Rate From the submitter: This site presents a new audio coder design that achieves efficient compression with fine-grain bitrate scalability. Issues regarding scalability are discussed, and a new approach to measuring coding efficiency is presented. A windows command-line demonstration coder is availiable to download. At present the coder achieves subjective transparency at approximately 96 kbit/s/chan, similar to the FhG (non-scalable) MP3 coder.
KT-Tech Incorporated Rate KT-Tech seems to be active in various compression areas, developing their own algorithms rather than implementing standards. Their web site has demos of their latest still image and video technologies. One interesting product is software to improve the performance of other encoders, such as those used by Microsoft’s Windows Media codecs.
Update: the web site now offers online demos of sound compression as well!
Complexity

Complexity International Rate Complexity International is a refereed journal for scientific papers dealing with any area of complex systems research.
Data Compression

Data Compression Conferences Jürgen Abel is now tracking conferences which will be covering data compression topics. This listing includes the conference, dates, web page, and submission deadline. You are encouraged to keep Jürgen updated with any new information.
Yahoo links to compression companies and products Rate
A pretty good list of links to companies that are doing business in the compression arena, and/or their products.
Welcome to compression consulting Rate
Michael Schindler’s home page for his business, which appears to be consulting in the field of data compression. His home page has a description of his business, as well as links to some informative pages he supports.
UCSB Signal Compression Lab Rate Various research areas of some interest in here.
ISO Informatique Rate This French company seems to have some image compression software or service to offer. The web page seems to be entirely in French, although it has some misleading links with a UK flag that you might think meant an English language version was available. Native speakers of French are encouraged to improve on this description.
Compression Register Rate A register of companies, people, and institutes having something to do with data compression.
ITU – International Telecommunication Union Rate The ITU, headquartered in Geneva, Switzerland is an international organization within which governments and the private sector coordinate global telecom networks and services. The ITU is the leading publisher of telecommunication technology, regulatory and standards information. Many publications can be purchased through our Electronic Bookshop or the ITU Publications Online subscription service.
Google’s Data Compression Software Directory Rate I think Google’s directory comes from the DMOZ directory, but I could be wrong. This page mostly has pointers to companies that sell software.
Fourelle Systems Rate Fourelle Systems, Inc.is the global market leader in accelerated content delivery. Venturi, Fourelle’s flagship product platform, speeds the performance of IP applications over WAN links including T1, frame relay, satellite, wireless, cable and dial-up. Venturi uses application level compressionand an optimized transport protocol to achieve up to 400% performance gains.
UCF VLSI and Data Compression Lab Rate The University of Central Florida Data Compression Lab has a lot of interesting stuff here. More than just academic papers, for example the M5 online compression utility!.
Esoterica/Miscellany

Zip Programs Can Identify Language Of Any Document Rate A couple of researchers from Rome have shown that adaptive compression algorithms can be used to accurately predict the language of the source text.
Cal Tech improves on 3D compression Rate CNN reports on a research team at Cal Tech that has created a new algorithm for compressing 3D object representations. If you can figure out how it works from this article, send me an email!
Fractals

Waterloo Fractal Compression Project Rate
The Waterloo Fractal Compression Project is part of a general research programme dedicated to the study of fractal analysis and Iterated Function Systems/Fractal Transforms from both theoretical as well as practical perspectives.
Signal and Image Processing Group Rate The University of Bath has a group that is advertised as “world leaders in still image and video coding.” They appear to be interested in lossy compression based on DCT, Wavelets, and Fractal compression. This is their home page.
Image Compression

RICAZip.com Rate
RICAZip.com has proprietary lossless image compression technology called RICA (Reversible Image Compression Algorithm). RICA retains original file formats (e.g. TIFF, DICOM, BMP, TGA, PGM etc.). RICACom says We have yet to find any method that provides better compression ratios (for truly lossless), including wavelet. On a PII 450MHz RICA compresses @ 6MB per second and decompresses at 12MB per second.
Available as a standalone image archive app, Adobe Photoshop Plugin, Browser Plugin, and RICA SDK.
DCL reader Karen H. says: Evaluation of this product demonstates excellent compression ratios and it is also very fast compared to other methods I have used.
Pegasus Imaging Corporation Rate
Pegasus Imaging Corporation has their fingers in many different pies, mostly related to imaging and image compression. This home page has links to many of their diffferent products, a variety of programs and libraries.
Tak’Asic Rate
Tak’Asic provides Lossless/Lossy still image compression/decompression ICs solution.
. Our ICs support JBIG, MH, MR, MMR and JPEG standards.
Our latest product, Tak’B3, is the world fastest JBIG codec available. It is able to process images at 133Mpixel/sec minimum and up to 2128Mpixel/sec. It also provides code conversion (MR/MR/MMR <-> JBIG) and scaling functionality.
DAKX LLC Home Page Rate DAKX is claiming a new method of lossless data compression that is fast and patented. It works on audio and video data. The method is called difference-adaptive compression. DAKX supplies a bit of source code that you can experiment with, and will be happy to license the technology to you or your company.
FMA&H Rate This page is a mystery to me.
LEAD Technologies, Inc. Rate These guys are big in the world of software that does image processing. What does this have to do with data compression? Well, they do have products that render, convert, and create compressed formats such as JPEG, TIFF, and GIF.
Accusoft Rate Accusoft makes a variety of imaging products, including a nice commercial imaging library.
IBM Research – Image application solutions Rate The image application group at IBM’s Watson Research Center works on quite a few different topics related to digital imaging, including image capture, color science, printing and displaying images, and so on. Of course, part of that is image compression, which is why we’re interested in them.
KT-Tech Incorporated Rate KT-Tech seems to be active in various compression areas, developing their own algorithms rather than implementing standards. Their web site has demos of their latest still image and video technologies. One interesting product is software to improve the performance of other encoders, such as those used by Microsoft’s Windows Media codecs.
Update: the web site now offers online demos of sound compression as well!
Incredible Claims

Pixelon Bites the Dust Rate
Pixelon shows what happens when technology gets mixed up with big bucks and shady characters. The Industry Standard ran a great story on it, but as they have gone belly up this link may not work any more. So this CNet news article will have to do.
Reader Tim A. points out that they also claim that ‘No longer is it necessary to produce complex waveforms by summing sinusoidal signals at varying frequencies’, yet later call their process an ‘additive reconstruction process’. Sounds much like the same process to me, just with different starting waveforms..
Web Technologies Rate
Byte looks back at the amazing compression claims of a company named Web Technlogies.
Wired Interviews ZeoSync CEO Rate Wired Magazine got ZeoSync CEO Peter St. George to sit down for a little chat. They posted the article here.
Slashdot Discusses Zeosync Rate The folks at Slashdot having their typical discussion re: the incredible claims from ZeoSync.
PCWorld: Questions Dog ZeoSync’s Compression Claim Rate PCWorld takes a skeptical look at Zeosync’s claims, and looks askance at the felony conviction of a key employee.
Chaotic Compression? Rate Kevin Short at the University of New Hampshire has created a company called Chaoticom that is raising money to develop his new idea called Chaotic Compression Technology. Until we see some papers, algorithms, or products this is going to have to be categorized as an Incredible Claim.
Adam Clark Finds a Buyer Rate It appears that the technology promised by Adam Clark has found a buyer. MWC is paying $11 million for the IP that is reputed to be able to create a full-screen video experience over normal voice lines.
Take A HyperDrive On The Internet Super Highway Rate Pegasus Web Services has a new compression algorithm that they say can put 1.2GB on a floppy disk! No demo software yet, but if you’re interested in licensing the technology they are ready to talk.
The Data Compression Newsletter #8 Rate This issue of the Data Compression Newsletter from DDJ highlights a few of the better Incredible Claims to come along – including the biggest of all, the Pixelon fraud case.
Information Theory

IEEE Information Theory Society Web Portal Rate
The home page for the society. Links to newsletters, conferences, tutorials, abstracts, and other miscellaneous fun things.
Quantum Random Number Generation Rate This web site offers you random numbers generated using quantum process, which sounds like the gold standard to me.
Info-ZIP

Info-ZIP Rate
Info-ZIP is a diverse, Internet-based workgroup of about 20 primary authors and over one hundred beta-testers, formed in 1990 as a mailing list hosted by Keith Petersen on the original SimTel site at the White Sands Missile Range in New Mexico.
Info-ZIP’s purpose is to provide free, portable, high-quality versions of the Zip and UnZip compressor-archiver utilities that are compatible with the DOS-based PKZIP by PKWARE, Inc.

Internet

Expand Networks Rate
Expand makes a series of Network Accelerators. These are black boxes that perform lossless compression on packets being shipped across our WAN. Lots of competition in this area, so companies like Expand depend on innovative and proprietary techniques to give them an edge.
Peribit Rate
These folks make a box that transparently compresses network traffic. Designed to work on any sort of WAN interface, including T1, E1, ATM, etc. The web site includes an ROI calcuator that will convince you this box will pay for itself!
Talleo Rate Talleo advertises themselves as an international telecommunications consulting firm that provides Network Engineering, WAN optimization, and data compression. They are a reseller of Peribit’s products.
JBIG

The JBIG Home Page Rate
Home page for the members of the JBIG committee, as well as a place for links and information about the Bi-Level Image coding standard.
Home site of the JPEG and JBIG committees Rate
As it says, this is the home site of the committees. You need to be a member to access some areas, but there is plenty of information here for the common man as well.
Tak’Asic Rate
Tak’Asic provides Lossless/Lossy still image compression/decompression ICs solution.
. Our ICs support JBIG, MH, MR, MMR and JPEG standards.
Our latest product, Tak’B3, is the world fastest JBIG codec available. It is able to process images at 133Mpixel/sec minimum and up to 2128Mpixel/sec. It also provides code conversion (MR/MR/MMR <-> JBIG) and scaling functionality.
JPEG

Pegasus Imaging Corporation Rate
Pegasus Imaging Corporation has their fingers in many different pies, mostly related to imaging and image compression. This home page has links to many of their diffferent products, a variety of programs and libraries.
Morgan Multimedia. Rate
This company makes a M-JPEG codec and would like to sell it to you. Much of the page is written in French.
Home site of the JPEG and JBIG committees Rate
As it says, this is the home site of the committees. You need to be a member to access some areas, but there is plenty of information here for the common man as well.
Independent JPEG Group Rate
The Independent JPEG Group is a source of free JPEG software. It is in wide use. Oddly enough, the groups home page doesn’t have anything interesting on it except a link to an ftp site, and a link to a couple of FAQs.
Tak’Asic Rate
Tak’Asic provides Lossless/Lossy still image compression/decompression ICs solution.
. Our ICs support JBIG, MH, MR, MMR and JPEG standards.
Our latest product, Tak’B3, is the world fastest JBIG codec available. It is able to process images at 133Mpixel/sec minimum and up to 2128Mpixel/sec. It also provides code conversion (MR/MR/MMR <-> JBIG) and scaling functionality.
Signal and Image Processing Group Rate The University of Bath has a group that is advertised as “world leaders in still image and video coding.” They appear to be interested in lossy compression based on DCT, Wavelets, and Fractal compression. This is their home page.
divio Rate Self-described leader in digital video and imaging technology, divio has a product line that includes hardware that implements MPEG-4, AAC, M-JPEG, and JPEG. Suitable for inclusion in both digital still and movie cameras.
Forgent’s Press Release on JPEG Patent Rate Forgent explains their position with respect to the infamous ‘672 patent.
Zoran Corporation Rate Zoran makes chips that do some MPEG decoding as well as JPEG codecs.
JPEG-2000

WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
Migrator 2000 Rate This group says that they will develop, demonstrate and disseminate tools for the JPEG 2000 digital imaging standard. At this time that seems to include a couple of demonstration programs, some text and web pages, test images, and a link to a Perl package.
JPEG-LS

HP Labs LOCO-I/JPEG-LS Home Page Rate
JPEG-LS is the new lossless/near-lossless compression standard for continuous-tone images developed by ISO/IEC JTC1/SC29/WG1 (final draft international standard FDIS14495-1 as of Novembr 1998). The standard is based on the LOCO-I algorithm (LOw COmplexity LOssless COmpression for Images) developed at Hewlett-Packard Laboratories
Update: The HP site has just added a JPEG-LS plugin for Photoshop, in addition to the HP implementation that has been there for some time.
Home site of the JPEG and JBIG committees Rate
As it says, this is the home site of the committees. You need to be a member to access some areas, but there is plenty of information here for the common man as well.
Lossless Compression

DC Micro Home page for DC Micro, home of Crusher!, the data compression toolkit
RICAZip.com Rate
RICAZip.com has proprietary lossless image compression technology called RICA (Reversible Image Compression Algorithm). RICA retains original file formats (e.g. TIFF, DICOM, BMP, TGA, PGM etc.). RICACom says We have yet to find any method that provides better compression ratios (for truly lossless), including wavelet. On a PII 450MHz RICA compresses @ 6MB per second and decompresses at 12MB per second.
Available as a standalone image archive app, Adobe Photoshop Plugin, Browser Plugin, and RICA SDK.
DCL reader Karen H. says: Evaluation of this product demonstates excellent compression ratios and it is also very fast compared to other methods I have used.
Advanced Hardware Architectures Rate
Home page for Advanced Hardware Architectures. AHA makes a few different chips that implement various forms of lossless data compression.
DAKX LLC Home Page Rate DAKX is claiming a new method of lossless data compression that is fast and patented. It works on audio and video data. The method is called difference-adaptive compression. DAKX supplies a bit of source code that you can experiment with, and will be happy to license the technology to you or your company.
Intelligent Compression Technologies Rate A company that speciailizes in providing compression technology to other companies.
Geolytics Rate This company appears to be in the business of packaging demographic data for research and commercial interests. As part of that, they apparently have some technology for performing some compression on the data sets.
Solution-Soft Rate Solution-Soft is the provider of software for online archiving and for bandwidth management in the Internet infrastructure and the enterprise. Solution-Soft’s products enable data files to be archived online and transferred faster over networks through a revolutionary technology providing transparent compression and decompression.
GT Technology Rate This site advertises a bunch of nifty looking codecs, including TELP, JPEG, Speech, MPEG, and wavelet compressors. I can’t quite determine exactly what form the products come in.
Data Compression Technology by Compris.com Rate These folks appear to be selling some lossless compression technology, but I’m not quite able to determine what it is.
QuikCat Technologies Rate These guys use compression to increase messaging throughput on your network. Looks like they work with Microsoft Exchange, as well as having a general purpose product for ISPs.
GEMAC Rate This company sells an IP core that performs lossless data compression. Not sure what algorithm they are using, it is described as “GEMAC’s data compression algorithm.” This algorithm was first published at DCC ’95, and is described as a hybrid of ZL1 and ZL2, created with the goal of maximizing compression rate.
Lossy Compression

Signal and Image Processing Group Rate The University of Bath has a group that is advertised as “world leaders in still image and video coding.” They appear to be interested in lossy compression based on DCT, Wavelets, and Fractal compression. This is their home page.
GeoEnergy, Inc. Rate Their home page advertises GeoEnergy as “The leader in fast data compression algorithms for the oil and gas industry.” Quite a few algorithms are listed, all of which work on various types of collected seismic data.
LZ78/LZW and derivatives

Unisys LZW Page Rate
Some information on LZW, it looks as though this has info on Licensing, but I’m not sure. All information is in Japanese.
MP3/MPEG Audio

Xing Technology Corporation Rate
Xing makes consumer products that support various forms of digital audio. Xing Audio Catalyst is a popular program that supports both creation and playback of MP3 audio.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
MP3 Upgrade in the Works? Rate ZDNet reports that MP3 patent holders, Fraunofer Institute and Thomson Multimedia are shopping around a new version of the aging audio standard. Formats such as Microsoft’s Windows Media format have been eating into the MP3 dominance on the net.
Coding Technologies Rate These guys are responsible for some of the work that took the MP3 standard to its next revision: MP3Pro. They say their current focus is the development and marketing of SBR-enhanced codecs.
MPEG

Pentamedia Rate
Among other things, these folks make a MPEG 1/2 A/V encoder board for your PC. As an added bonus, their site comes in English, Spanish, and Korean versions.
The MPEG home page Rate
An impressive set of links to papers, schedules, articles, and contacts for MPEG. Clearly the place to go for information relating to the standardization process.
Cloud Systems Rate
These folks would like to do video compression for you, helping you with your CD-ROM or DVD products.
UB Video, Inc. Rate
UB Video says: UB Video Inc., based in Vancouver, Canada, is a leading provider of coding and transcoding software solutions for video communications. UB Video provides software products that run on desktop PCs as well as on programmable Digital Signal Processors and Media Processors. UB Video’s products include:
Encoders/Decoders
H.261 (Libraries/Source code)
H.263/H.263+ (Libraries/Source code, Encoder/Decoder DirectShow filters, Video for Windows codecs, Java decoder)
MPEG-4 (Libraries/Source code)
MPEG-2 (Libraries/Source code) Transcoders
H.263 to H.261 and H.261 to H.263 (Libraries)
MPEG-2 to MPEG-4 (Libraries) Free demos of the H.263+ codec (UB-Live) and MPEG-4 codec (UB-Stream) can be downloaded from the web site.
IETF AVT Working Group Rate
This is the home page for the IETF group that reviews RTP packetization standards. Links on this page for all the drafts you can imagine for sending video and audio over RTP streams.
Philips – Business Team Sound Coding Rate
Historically, the BTSC has been involved in MPEG Audio from the very start. This site provides some background information on the various MPEG Audio standards.
This site provides some info on the background of MPEG, plus a couple of links to standards and so on.

WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
Zapex Rate Zapex makes chips, chip cores, and boards dedicated to real time compression, including MPEG-2 and AC3.
Tiernan Communications, Inc. Rate These folks sell a couple of boxes that do MPEG-2 encoding. Looks like they are oriented towards the video broadcasting business.
Precision Digital Images Rate This company makes digital video streaming hardware and software. Although it looks like maybe they don’t actually make the hardware, they help you design it.
Digital Video Compression Center Rate These folks are ready to provide you with DVD encoding and authoring help for your feature film.
Optivision Rate This company says they are a big name in the world of network streaming video. Products on their web side seem to be oriented towards MPEG.
Sigma Designs Rate Sigma makes hardware MPEG decoders. You might need one of these if you’re designing a set-top box or a new PC video card.
iVAST Rate This company labels itself as “The world leader in end-to-end MPEG-4 Solutions.” Looks like they sell a suite of authoring and encoding tools, and perhaps some server software. Follow the link to “About MPEG-4″ and you’ll get a little bit of text plus some more links.
divio Rate Self-described leader in digital video and imaging technology, divio has a product line that includes hardware that implements MPEG-4, AAC, M-JPEG, and JPEG. Suitable for inclusion in both digital still and movie cameras.
MPEG-4 foe calls for antitrust probe Rate On2 Technologies is asking the US Department of Justice to take action against the coalition of MPEG-4 patent holders, arguing that the coalition is anti-competitive. Maybe not just a coincidence, On2 is presently pushing their own streaming format with industry standards groups.
Zoran Corporation Rate Zoran makes chips that do some MPEG decoding as well as JPEG codecs.
Nvideo-Tech Rate These guys make the MpegDecSdk, which appears to be a free library for Windows and Linux. Way short on documentation at this point!
Philips MP4Net Rate Philips MP4Net web site is here to tell you abou the WebCine line of products, which includes an MPEG-4 Encoder, Server, and Player. It looks like the player is yours for the asking. Other links here explain MPEG-4, as well as offering you careers with Philips.
The MPEG Industry Forum Rate Stated objective: To further the adoption of the MPEG-4 Standard, by establishing MPEG-4 as an accepted and widely used standard among application developers, service providers, content creators and end users..
Update: This group has now changed it’s name to The MPEG Industry Forum, and have expanded their charter to include all emerging MPEG standards. For right now that includes MPEG-7 and MPEG-21, but we’re not ruling out anything in the future.
GT Technology Rate This site advertises a bunch of nifty looking codecs, including TELP, JPEG, Speech, MPEG, and wavelet compressors. I can’t quite determine exactly what form the products come in.
MPEG LA Rate This company is the licensing authority created by the owners of the most or all of the patents related to MPEG. Apparently they have the authority to provide one-stop shopping for your royalty arrangements.
Quantization

SPACL Rate
The Signal Processing and Coding Laboratory (SPACL) at The University of Arizona has some papers on line, plus some information on their current projects. They seem to be interested in wavelets, quantization, and signal coding.
A DCL reader complained: Very little useful information on the website. On topic, but not helpful at all.
Speech

Nellymoser Rate
Nellymoser is the leading provider of proprietary speech and audio software technology and solutions in the areas of compression, modification, synchronization and conversion. Our products improve speech and audio quality and efficiency in bandwidth-constrained environments while creating more immersive, interactive environments for your applications and services.
VoiceAge Corporation Rate
Our technology served as the foundation for numerous voice compression products used by voice portal and large multinationals in their efforts to better meet the quality requirements that end users. As example voice email, voice chatting, voice annotation in web site. Our technology is already integrated into software by companies such as Microsoft with its Netshow® software and in its Mediaplayer®, and RealNetworks within its RealAudio® and RealVideo®. In addition, over the last decade this compression technology (over 100 patents) was positioned in several International Telecommunication standards, notably: GSM ,PCS, TDMA ,CDMA, TETRA, G.729 . VoiceAge’s compression technology is well positioned at cross road of internet and voice for next-generation of voice portal.
IETF AVT Working Group Rate
This is the home page for the IETF group that reviews RTP packetization standards. Links on this page for all the drafts you can imagine for sending video and audio over RTP streams.
Sipro Lab Telecom Rate
These folks make several different G.729 and G.723.1 codecs,
Zarak Systems PSQM Testing Rate
Zarak Systems will perform Quality of Service testing using PSQM, the Perceptual Speech Quality Measurement. This web page will tell you a little bit about what that means to you.
Algorithm cuts VoIP bandwidth requirement Rate A company named Effnet Inc. is licensing a version of CRTP, a protocol that compresses packet headers in RTP streams. With small VOIP packets this can provide substantial savings.
IstraSoft Rate IstraSoft appears to make some speech codecs, supplied as Windows DLLs. Plus some discussion on their web page re: English phonetics.
GT Technology Rate This site advertises a bunch of nifty looking codecs, including TELP, JPEG, Speech, MPEG, and wavelet compressors. I can’t quite determine exactly what form the products come in.
Video

XiWave Rate
XiWave’s wavelet-based Xi-3 codec is our latest dynamically scalable software codec (coder-decoder) and offers one of the best available today addressing the challenge of transmitting high quality digital images using the least bandwidth
USA Video Interactive Rate
These guys say that they are establishing a leadership position in the streaming video arena. They have some good information about wavelet compression on their page.
Essential Viewing Rate
Our technology set is based on the Essential Video 4.0 codec, which is a flexible and dynamic codec which utilises a number of video compression techniques using our BestFirst algorithm; methods include vector quantisation, motion compensation and residual encoding.
Cloud Systems Rate
These folks would like to do video compression for you, helping you with your CD-ROM or DVD products.
UB Video, Inc. Rate
UB Video says: UB Video Inc., based in Vancouver, Canada, is a leading provider of coding and transcoding software solutions for video communications. UB Video provides software products that run on desktop PCs as well as on programmable Digital Signal Processors and Media Processors. UB Video’s products include:
Encoders/Decoders
H.261 (Libraries/Source code)
H.263/H.263+ (Libraries/Source code, Encoder/Decoder DirectShow filters, Video for Windows codecs, Java decoder)
MPEG-4 (Libraries/Source code)
MPEG-2 (Libraries/Source code) Transcoders
H.263 to H.261 and H.261 to H.263 (Libraries)
MPEG-2 to MPEG-4 (Libraries) Free demos of the H.263+ codec (UB-Live) and MPEG-4 codec (UB-Stream) can be downloaded from the web site.
IETF AVT Working Group Rate
This is the home page for the IETF group that reviews RTP packetization standards. Links on this page for all the drafts you can imagine for sending video and audio over RTP streams.
Pixelon Bites the Dust Rate
Pixelon shows what happens when technology gets mixed up with big bucks and shady characters. The Industry Standard ran a great story on it, but as they have gone belly up this link may not work any more. So this CNet news article will have to do.
Reader Tim A. points out that they also claim that ‘No longer is it necessary to produce complex waveforms by summing sinusoidal signals at varying frequencies’, yet later call their process an ‘additive reconstruction process’. Sounds much like the same process to me, just with different starting waveforms..
Indeo Rate What was once Intel’s software now belongs to Ligos Technology. This is the home page for downloads, documentation, support, etc.
Sorenson Vision Rate Sorenson makes hardware and software for video conferencing and other video streaming apps.
The Video Quality Experts Group Rate A growing concern for video researchers and broadcasters alike, is the assurance and maintenance of an acceptable service quality level for the distribution of video programming. The Video Quality Experts Group (VQEG) was created to deal with video quality issues, specifically, objective methods for predicting video image quality.
Crystal Net Rate These guys have a low bit rate video codec designed to transmit moving pictures over POTS lines, with associated products that take advantage of the code.
Precision Digital Images Rate This company makes digital video streaming hardware and software. Although it looks like maybe they don’t actually make the hardware, they help you design it.
Digital Video Compression Center Rate These folks are ready to provide you with DVD encoding and authoring help for your feature film.
Optivision Rate This company says they are a big name in the world of network streaming video. Products on their web side seem to be oriented towards MPEG.
8X8, Inc. Rate 8×8 is a leading manufacturer of digital telecommunication products, including both central office and customer premise equipment for Internet Protocol (IP) telephony.
ACM Multimedia 2002 Rate The ACM Multimedia conference for 2002 takes place December 1-6, 2002 in beautiful Juan-les-Pins on the French Riviera. Get your submissions in quick before the show fills up.
On2 uses new video compression on film Rate CNet reports that On2 Technologies is using a feature film to demo their new compression technology. You can see “To Kill a Lawyer” over the Internet at several speeds ranging from 400 KBps up to 1MBps. The proprietary algorithm is called VP5.
RealNetworks Helix Initiative Rate RealNetworks has announced that they are going to be Open Sourcing a significant portion of their server products. Outlook from the Open Source community is guardedly optimistic.
Windows Media High Definition Video Rate Microsoft thinks Windows Media Video can be a big part of the HD scene. This web page is dedicated to that proposition.
NSF I/U Center for Next Generation Video Rate The Center for Next Generation Video is working on a number of research projects dealing with advanced video coding.
Overview of the Nancy Codec Rate This PDF file provides a two page overview of the Nancy codec and the company that’s behind it, NOA, Inc.
KT-Tech Incorporated Rate KT-Tech seems to be active in various compression areas, developing their own algorithms rather than implementing standards. Their web site has demos of their latest still image and video technologies. One interesting product is software to improve the performance of other encoders, such as those used by Microsoft’s Windows Media codecs.
Update: the web site now offers online demos of sound compression as well!
Pulsent promises bang-up video compression Rate Privately held Pulsent is promising a new video compression technique that can stream video across the net with only half the bandwidth of MPEG2. They’ve not only created a new algorithm but are also developing the chips to support it.
CEO leads cell phones to real-time rock Rate An article in EE Times that talks about the CEO of the company producing the Nancy video codec. Nancy has significantly lower MIPS requirements than MPEG-4, which has gotten it in the door of Japan’s 2.5G cell phone manufactures.
Wavelets

XiWave Rate
XiWave’s wavelet-based Xi-3 codec is our latest dynamically scalable software codec (coder-decoder) and offers one of the best available today addressing the challenge of transmitting high quality digital images using the least bandwidth
USA Video Interactive Rate
These guys say that they are establishing a leadership position in the streaming video arena. They have some good information about wavelet compression on their page.
Essential Viewing Rate
Our technology set is based on the Essential Video 4.0 codec, which is a flexible and dynamic codec which utilises a number of video compression techniques using our BestFirst algorithm; methods include vector quantisation, motion compensation and residual encoding.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
SPACL Rate
The Signal Processing and Coding Laboratory (SPACL) at The University of Arizona has some papers on line, plus some information on their current projects. They seem to be interested in wavelets, quantization, and signal coding.
A DCL reader complained: Very little useful information on the website. On topic, but not helpful at all.
Signal and Image Processing Group Rate The University of Bath has a group that is advertised as “world leaders in still image and video coding.” They appear to be interested in lossy compression based on DCT, Wavelets, and Fractal compression. This is their home page.
UC Berkeley Wavelet Group Rate The wavelet group has links to books, publications, and people doing wavelet things. Link updated to new location January 2002
TMR – Wavelets in Numerical Simulation Rate This page reflects the necessity of developping collaborations (and intensify those that already exist) between the nine research groups from six different european countries, with the ultimate common goal of applying wavelet-based methods to complex industrial problems.
Compression Engines, Inc. Rate Compression Engines, Inc. has a file format called WIF, which stands for Wavelet Image Format. They licensed it from HARC, and have created and ActiveX control, a browser plugin, a standalone program, and the requisite Photoshop plugin. Check it out.
GT Technology Rate This site advertises a bunch of nifty looking codecs, including TELP, JPEG, Speech, MPEG, and wavelet compressors. I can’t quite determine exactly what form the products come in.
Zip

DC Micro Home page for DC Micro, home of Crusher!, the data compression toolkit
Xceed Software, Inc. Makers of high-quality, commercial-grade data compression, encryption and internet components for Windows developers.
Greenleaf Software Rate Greenleaf sells ArchiveLib, an archiving library that supports both Zip and a proprietary format
Ascent Solutions, Inc. Rate ASCENT SOLUTIONS Inc. PKZIP data compression software for MVS (mainframe), Windows (Netzip), VM, VSA, AS/400, UNIX, OS/2, DOS, VMS. All products are 100% cross-platform compatible.
zlib

Zlib flaw leaves Linux computers vulnerable Rate CNET reports the existence of a bug in zlib that leaves room for security exploits. The bug is one that occurs when a program attempts to free allocated memory twice, which leaves the internals of the library in an unpredictable state.
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Complexity

Complexity research tries to apply absolute numbers to the question regarding how complex a data sequence is, which in turn has something to say about how well the sequence will compress. Traditional data compression research dodges the question of absolute complexity, instead always referring to the entropy of a data stream “with respect to a given model.” Complexity studies the entropy of a sequence with respect to God’s model.
[ Deja News ] Search compression newsgroups for references to this topic
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Amazon Honor System
Companies/Organizations

Complexity International Rate Complexity International is a refereed journal for scientific papers dealing with any area of complex systems research.
Courses/Seminars

Andrei Nikolaevich Kolmogorov Rate This site is dedicated to the Centennial of Andrei Nikolaevich Kolmogorov, a leading light in the field of complexity. The site contains the information for a conference being held in his honor in Moscow during June, 2003.
Links

Kolmogorov Complexity Rate The definition from the NIST Dictionary of Algorithms and Data Structures.
Newsgroup Posts

Complexity and Entanglement Rate Charles Bloom thinks out loud about complexity.
Papers/Documentation

Data Compression Newsletter #20 – Randomness and Complexity Rate This issue of the newsletter talks about randomness, complexity, and a long-time favorite, recursive compression.
Complexity International Rate Complexity International is a refereed journal for scientific papers dealing with any area of complex systems research.
People

Kolmogorov, Andrey Nikolayevich Rate
A short bio of the famous Russian mathematician. His name lives on in comp.compression and elsewhere due to his seminal work in the study of complexity.
G J Chaitin Rate G.J. Chaitin seems to be interested in complexity and information theory.
Tutorials, Reference, Presentations

Information Content and Compression Limit FAQ Rate
How much can a given piece of data be compressed? This FAQ addresses that question, including some necessary critiques of the question itself. Graham Fyffe apparently spends some time thinking about complexity.
Kolmogorov Complexity Rate The definition from the NIST Dictionary of Algorithms and Data Structures.
Wikipedia Entry: Algorithmic Information Theory Rate The Wikipedia entry for Algorithmic Information Theory. Explains the field of study that includes such interesting things as Kolmogorov complexity.
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Courses/Seminars

Throw in conferences and exhibits and you should have a complete understanding of what’s being presented in this section.
[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Audio

Multimedia Computing and Networking 2002 Rate The term “Multimedia” obviously covers a lot of different topics. Compression is one of them, and there is certainly a great deal to learn about compression and media formats at this conference.
ACM Multimedia 2002 Rate The ACM Multimedia conference for 2002 takes place December 1-6, 2002 in beautiful Juan-les-Pins on the French Riviera. Get your submissions in quick before the show fills up.
Complexity

Andrei Nikolaevich Kolmogorov Rate This site is dedicated to the Centennial of Andrei Nikolaevich Kolmogorov, a leading light in the field of complexity. The site contains the information for a conference being held in his honor in Moscow during June, 2003.
Data Compression

Data Compression Conferences Jürgen Abel is now tracking conferences which will be covering data compression topics. This listing includes the conference, dates, web page, and submission deadline. You are encouraged to keep Jürgen updated with any new information.
Data Compression Conference 1998 – Proceedings Rate
All of the papers from the 1998 Data Compression Conference are available here on line.
Data Compression Conference 1997 – Proceedings Rate
All of the papers from the 1997 Data Compression Conference are available here on line.
Data Compression Conference 2000 – Proceedings Rate
All of the papers from the 2000 Data Compression Conference are available here on line.
Data Compression Conference 1999 – Proceedings Rate
All of the papers from the 1999 Data Compression Conference are available here on line. Yes, there is a catch – you will have to pay if you want to do more than read the abstract. (Looks like a strong incentive to become a member of the IEEE Computer Society.)
The Data Compression Conference Rate
IEEE Data Compression Conference (DCC’2002), held each spring in Snowbird, Utah. This is the main event in the compression world. Note that the 2002 advance program is available here as of 3/02.
EE 5585 Home Page Rate
A collection of class notes, homework assignments, and links for a class on Data Compression at the University of Minnesota.
Information Theory Research Group Rate
Home page for John C. Kieffer, Dept. of EE, University of Minnesota. Includes course descriptions for classes on data compression and information theory. The course descriptions have links to some papers.
EE372 Home Page QUANTIZATION and Data Compression and Rate A basic syllabus and links giving a wide survey of the field.
CMPE 263 Handouts by Glen Langdon Rate A set of handouts for a survey course on Data Compression, inlcuding papers on various types of coding, information theory, and more. An academic approach to the topics but quite accessible.
Principles of compression techniques Rate A set of slides, apparently for a course talking about data compression.
Image Compression

Multimedia Computing and Networking 2002 Rate The term “Multimedia” obviously covers a lot of different topics. Compression is one of them, and there is certainly a great deal to learn about compression and media formats at this conference.
TSBK01 Image Coding and Data Compression Rate A course being given by the Image Coding Group at Linköping University. Contains a few useful links plus some course material.
Information Theory

A Short Course in Information Theory Rate
8 lectures by David J.C. MacKay January 1995. Cavendish Laboratory, Cambridge, Great Britain. All of these lectures are available as PostScript files. The eight lectures cover data compression, coding, arithmetic coding, noisy channel coding, and much more
International Symposium on Information Technology: Coding and Computing ITCC 2000 Rate
Sponsored by IEEE Computer Society March 27-29, 2000, Las Vegas, Nevada
Topics include, but are not limited to, the following:

Digital Image Processing Data Storage Platforms
Document Image Analysis Optical Data Transmission
Data Compression New Architectures for Multimedia
Authentication of Video and Audio Processing
Data Graphics and Video Hardware
Multimedia Computing Error Control Codes
Hybrid Source/Channel Coding Video and Audio Codec Design
Systems Interfacing and Enterprise Architectures
Integration Enterprise-wide Information
Information Databases Management
Information Theory Research Group Rate
Home page for John C. Kieffer, Dept. of EE, University of Minnesota. Includes course descriptions for classes on data compression and information theory. The course descriptions have links to some papers.
EE376B/Statistics 376B: Information Theory Rate
A course outline from Stanford.
Information Theory Rate Lecture notes for a course on Information Theory, by John Lafferty, School of Computer Science, Carnegie Mellon University. Includes handouts, problem sets, code, additional lectures, and a page of links.
CMPE 263 Handouts by Glen Langdon Rate A set of handouts for a survey course on Data Compression, inlcuding papers on various types of coding, information theory, and more. An academic approach to the topics but quite accessible.
Lossy Compression

Multimedia Computing and Networking 2002 Rate The term “Multimedia” obviously covers a lot of different topics. Compression is one of them, and there is certainly a great deal to learn about compression and media formats at this conference.
LZ77/LZSS and derivatives

Redundanz – Lempel-Ziv-Kodierung Rate
A lecture in German on LZ coding.
LZ78/LZW and derivatives

Redundanz – Lempel-Ziv-Kodierung Rate
A lecture in German on LZ coding.
MPEG

Toshiba Announces MPEG-4 Support Chips Rate Toshiba is creating MPEG-4 support chips that vendors are looking to included in mobile handset. This article notes that the chipset will be designed to work with specific baseband hardware, such as Qualcomm’s, and might not work elsewhere.
Speech

Speech Coding Rate
What appears to be a course or lecture outline on speech coding.
Suffix Trees

Notes on suffix tree construction Rate
Notes on suffix tree construction, some course notes for COMP 612: Graduate Seminar in Compiler Construction, includes some pointers to important papers.
DataCompression.info user David D. had this complaint: None of the links work on this page, all there is is a short paragraph on suffix trees. I have to agree, it’s a rather strange page.
Video

ACM Multimedia 2002 Rate The ACM Multimedia conference for 2002 takes place December 1-6, 2002 in beautiful Juan-les-Pins on the French Riviera. Get your submissions in quick before the show fills up.
Wavelets

Applied Wavelet Analysis Courses Rate The following short courses are offered in 1998-1999, based on the book A Friendly Guide to Wavelets by Gerald Kaiser:
A Detailed Introduction to Wavelets With Applications to Image Analysis and Lossless Coding
A Detailed Introduction to Mathematical and Physical Wavelets With Applications to Image Analysis, Sonar and Radar
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Data Compression

This is the catch all category for the library. Wherever possible, I try to categorize an entry with as refined a label as possible. But some web pages, papers, or books cross through many different categories, including lossy, lossless, image, audio, etc. Those things have to be categorized here. A good example would be the comp.compression newsgroup, which covers everything related to data compression.
Books

The Data Compression Book The home page of The Data Compression Book. This is an introductory text oriented towards practical programming.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Mark Nelson Mark Nelson’s home page, with links to his books and articles.
Managing Gigabytes, 2nd Edition – Witten, Moffat, and Bell Rate
The second edition of Managing Gigabytes: Compressing and Indexing Documents and Images by Ian H. Witten, Alistair Moffat, and Timothy C. Bell, is now available (May 1999), published by Morgan Kaufmann Publishing, San Francisco, ISBN 1-55860-570-3.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Data Compression: The Complete Reference, 2nd edition Rate
by David Salomon. This book is intended to provide an overview of the many different types of compression: it includes a taxonomy, an analysis of the most common systems of compression, discussion of their relative benefits and disadvantages, and their most common usages.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Which books should I read? Rate
An answer to this question from the comp.compression FAQ.
Data Compression from The Scientist and Engineer’s Guide to Digital Signal Processing Rate
A sample chapter from The Scientist and Engineer’s Guide to Digital Signal Processing, which just happens to be on Data Compression. You can download this entire book for free from the web site.
However, if you wish to purchase the hardcopy, please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Introduction to Data Compression, Second Edition Rate
by Khalid Sayood, University of Nebraska, Lincoln. 2000 600 pages, $69.95, ISBN 1-55860-558-4. This is a college level introductory text that covers a very wide range of data compression topics.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Compression Algorithms for Real Programmers by Peter Wayner Rate
“. Compression Algorithms for Real Programmers describes the basic algorithms and approaches for compressing information so you can create the smallest files possible.”
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Data and Image Compression: Tools and Techniques, 4E Rate
by Gilbert Held, Thomas R. Marshall. <
If you are interested in buying this book, please use the link on this page. Your purchase will help to support this site.
Introduction to Information Theory and Data Compression Rate Home page for the book: Introduction to Information Theory and Data Compression Darrel Hankerson, Greg A. Harris, and Peter D. Johnson Jr.
Buy from Amazon.com
Introduction to Information Theory and Data Compression (Discrete Mathematics and Its Applications Series) Rate by Hankersson et. al. Hardcover – 330 pages (November 1997) CRC Press; ISBN: 0849339855. A textbook for upper-level or graduate course on compression. Please use the link on this page to purchase this book, it will help support the Data Compression Library.
Compression and Coding Algorithms Rate by Alistair Moffat and Andrew Turpin. This book is scheduled for publication in 2002 by Kluwer Academic Publishers. This site has a table of contents and some sample pages to peruse while you wait for it to be printed.
This book now shows up as available on Amazon.com. Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Data Compression Bibliography Rate The University of Washington has a nice bibliography here, with pointers to books on Data Compression, VQ, Wavelets, and Information Theory.
Commercial Libraries

Xceed Zip Compression Library A feature-rich COM/ActiveX and DLL component for adding Zip and Unzip to your Windows apps with minimum effort. Includes full documentation with many samples and examples for VB, VC++, Delphi and C++Builder to get you started quickly. Supports the latest zip file format updates including Deflate64 compression and Zip64 headers. Also includes BZip2 compression which is excellent for compressing XML data.
Xceed Zip for .NET A true native Microsoft.NET Zip file-handling and streaming compression class library. Its true object-oriented design makes manipulating zip files as easy as manipulating regular files and folders. Written entirely in managed C#, it includes a variety of VB.NET and C# samples and takes full advantage of the .NET runtime’s capabilities.
Xceed Streaming Compression Library The Xceed Streaming Compression Library is a high-performance “raw” compression library. It offers the ability to compress and decompress streaming data, buffers, strings or single files and supports multiple compressed data formats. Unlike the Xceed Zip Compression Library, this ultralight library doesn’t offer Zip file handling capabilities.
Programmer’s Heaven Compression Programs Rate
A really nice set of programs and source code for all sorts of data compression. This area doesn’t appear to be actively maintained, so there are plenty of out-of-date files, but good stuff mixed in as well.
LuraDocument Rate LuraDocument represents an innovative compression software custom-tailored to the compression of scanned color documents composed of both images and text. The documents are partitioned into pure picture and pure text segments through the use of its state-of-the-art segmentation algorithm. Each of these segments is then compressed using an algorithm optimized for this type of data. As a result, scanned color documents can be stored at extremely high quality despite small file sizes. LuraDocument is capable of reaching compression rates of 1:150 to 1:500 while still preserving full readability of the text and excellent quality of the pictures. This makes LuraDocument far superior to even the wide spread PDF format.
Power SDK Rate Image Power makes a C++ SDK that performs both document and image compression. This supports JBIG2, MRC (Mixed Raster Content), and plugins for web browsers.
Delphi Skunkworks – Data Compression Rate A page full of links to data compression resources for Delphi Programmers. Mostly libraries.
Commercial Programs

AOL.COM search: Home > Computers > Software > Data Compression Rate
AOL search page with links to commercial and free data compression programs, and the companies that produce them.
Miliki Super Compressor Professional Rate
This product is advertised as a revolutionary compression package from QuickCAT Technologies. It comes in two versions: a Pro package that compresses documents and images, and a Basic version that compresses only images.
Source and Executables for the Amiga Rate
A huge selection of compression source and executables for the enigmatic Amiga.. I don’t know if this is a mirror site or independent.
FEI STU Bratislava,Slovakia,Europe Rate
A very complete archive of compression programs, freeware, shareware, source, archviers, compressors, etc. They have it all. At last count this site has at least 1000 compression downloads
Stuba mirror site Rate A mirror site for the big compression software site. See 0index.txt for a list of what’s here, an unbelievably large treasure trove.
XTREAM Rate The XTREAM Data Management System (XMS) is a robust, scalable data compression system that offers increased compression ratios and/or reduced compression processing time for efficient data management.
Note: I have to confess that after looking at this web page, I have absolutely no idea what this product does, how one would use it, or what the potential market is.
Archiving Encrypting Tiny File Splitter Rate Oleg Z. has created this program to to split, encrypt with your own unique key, compress and restore to original state large files of any type. The author says the program has an intuitive GUI, and works on most Win32 platforms.
Version 1.0.0.1 shipped on March 6, 2003.
Companies/Organizations

Data Compression Conferences Jürgen Abel is now tracking conferences which will be covering data compression topics. This listing includes the conference, dates, web page, and submission deadline. You are encouraged to keep Jürgen updated with any new information.
Yahoo links to compression companies and products Rate
A pretty good list of links to companies that are doing business in the compression arena, and/or their products.
Welcome to compression consulting Rate
Michael Schindler’s home page for his business, which appears to be consulting in the field of data compression. His home page has a description of his business, as well as links to some informative pages he supports.
Compression Register Rate A register of companies, people, and institutes having something to do with data compression.
ISO Informatique Rate This French company seems to have some image compression software or service to offer. The web page seems to be entirely in French, although it has some misleading links with a UK flag that you might think meant an English language version was available. Native speakers of French are encouraged to improve on this description.
Fourelle Systems Rate Fourelle Systems, Inc.is the global market leader in accelerated content delivery. Venturi, Fourelle’s flagship product platform, speeds the performance of IP applications over WAN links including T1, frame relay, satellite, wireless, cable and dial-up. Venturi uses application level compressionand an optimized transport protocol to achieve up to 400% performance gains.
UCSB Signal Compression Lab Rate Various research areas of some interest in here.
ITU – International Telecommunication Union Rate The ITU, headquartered in Geneva, Switzerland is an international organization within which governments and the private sector coordinate global telecom networks and services. The ITU is the leading publisher of telecommunication technology, regulatory and standards information. Many publications can be purchased through our Electronic Bookshop or the ITU Publications Online subscription service.
UCF VLSI and Data Compression Lab Rate The University of Central Florida Data Compression Lab has a lot of interesting stuff here. More than just academic papers, for example the M5 online compression utility!.
Google’s Data Compression Software Directory Rate I think Google’s directory comes from the DMOZ directory, but I could be wrong. This page mostly has pointers to companies that sell software.
Courses/Seminars

Data Compression Conferences Jürgen Abel is now tracking conferences which will be covering data compression topics. This listing includes the conference, dates, web page, and submission deadline. You are encouraged to keep Jürgen updated with any new information.
The Data Compression Conference Rate
IEEE Data Compression Conference (DCC’2002), held each spring in Snowbird, Utah. This is the main event in the compression world. Note that the 2002 advance program is available here as of 3/02.
Data Compression Conference 2000 – Proceedings Rate
All of the papers from the 2000 Data Compression Conference are available here on line.
Data Compression Conference 1999 – Proceedings Rate
All of the papers from the 1999 Data Compression Conference are available here on line. Yes, there is a catch – you will have to pay if you want to do more than read the abstract. (Looks like a strong incentive to become a member of the IEEE Computer Society.)
EE 5585 Home Page Rate
A collection of class notes, homework assignments, and links for a class on Data Compression at the University of Minnesota.
Data Compression Conference 1997 – Proceedings Rate
All of the papers from the 1997 Data Compression Conference are available here on line.
Data Compression Conference 1998 – Proceedings Rate
All of the papers from the 1998 Data Compression Conference are available here on line.
Information Theory Research Group Rate
Home page for John C. Kieffer, Dept. of EE, University of Minnesota. Includes course descriptions for classes on data compression and information theory. The course descriptions have links to some papers.
EE372 Home Page QUANTIZATION and Data Compression and Rate A basic syllabus and links giving a wide survey of the field.
Principles of compression techniques Rate A set of slides, apparently for a course talking about data compression.
CMPE 263 Handouts by Glen Langdon Rate A set of handouts for a survey course on Data Compression, inlcuding papers on various types of coding, information theory, and more. An academic approach to the topics but quite accessible.
Files

Data Compression Corpora Jürgen Abel has a great Data Compression site, and keeps a set of pointers to standard sets of files used for compression. He recently added a reference to the Protein Corpus, a set of difficult to compress files that were first published at the 1999 Data Compression Conference.
Matsusaka University Anonymous FTP Server Rate
An ftp site for compression software. This includes mirrors of some hard to find sites, such as those of D.J. Wheeler. Needs organization, and I often find it a bit slow from the US.
Data Compression Benchmark Suite Rate A set of links to files that are used to benchmark various data compression algorithms.
The New Canterbury Corpus Rate No details, but it appears to be a collection of files designed to represent a slightly wider range of modern applications.
French

Compression des images (et autres documents) Rate
This site has pointers to various sits related to image compression. The entire site is written in French.
German

Kompressionsalgorithmen Rate
A big survey paper of data compression techniques by Joachim Schwarz und Guido Sörmann. German language.
AG Information und Komplexität Rate A nice set of links to various resources related to info theory and data compression. German language.
Hardware

Fourelle Systems Rate Fourelle Systems, Inc.is the global market leader in accelerated content delivery. Venturi, Fourelle’s flagship product platform, speeds the performance of IP applications over WAN links including T1, frame relay, satellite, wireless, cable and dial-up. Venturi uses application level compressionand an optimized transport protocol to achieve up to 400% performance gains.
Italian

Giovanni Manzini Rate
Giovanni Manzini has published papers covering a few different topics in Data Compression, including several recent works on Burrows-Wheeler algorithms. He is currently an Associate Professor of Computer Science at the Universita degli Studi del Piemonte Orientale in the the most northern reaches of Italy.
Paolo Ferragina Rate
Paolo Ferragina’s research in data structures and string matching naturally lends itself to Data Compression and to the problem of indexing compressed data. See the link to his recent papers on indexing BWT compressed files. He is currently an Associate Professor of Computer Science at the University of Pisa.
Japanese Language Resources

Mitsuharu ARIMURA’s Bookmarks on Source Coding/Data Compression Rate
An enormous page of data compression links, well organized by type. Although this page is hosted in Japan, nearly all of the links are described in English.
Bibliography on Source Coding/Data Compression Rate Mitsuharu Arimura’s page of links and references to a wide variety of papers and books on lossless compression. Some of the links are listed in English, others in Japanese.
Data Compression Pointers Rate A set of data compression links maintained by Haruhiko Okumura. Many of the links here point to Japanese language sites. Even if you cannot read Japanese, you may still profit from the profusion of links on this page. Just be sure your browser is set to render Shift-JIS.
Data Compression in Japan Rate I need a translation of this page from any interested volunteer.
Unknown Rate I need a translation of this page from any Japanese speaking volunteers.
Links

BitJazz Compression Software Links The folks at BitJazz maintain a nice list of links to data compression directories. That makes this page sort of a meta-directory.
Mitsuharu ARIMURA’s Bookmarks on Source Coding/Data Compression Rate
An enormous page of data compression links, well organized by type. Although this page is hosted in Japan, nearly all of the links are described in English.
AOL.COM search: Home > Computers > Algorithms > Compression Rate
The compression algorithms page under AOL.COM’s search engine.
David Pereira Coutinho Rate
Personal page of David Pereira Coutinho, Professor at Instituto Superior de Engenharia de Lisboa. This page contains links to several compression-related abstracts and papers, as well as links to the Data Compression Framework developed with his students. (Indexed here as The DCG Framework.) The majority of the page is available in English and Portuguese.
Data Compression Site Rate
This site is in Russian, so I am not able to tell you much about it. It has links to some papers, and seems to have a link to PDF files that comprise much of a book on compression.
Reader Dan L. says The best site about comression!
Markus F.X.J. Oberhumer: Data Compresson Links Rate
Just what it says. A massive set of links.
David Cary’s Data Compression Links Rate
A huge number of links, thoughts, and documentation on a wide variety of data compression topics.
The Green Tree Of Compression Methods Rate
A Practical Introduction To Data Compression by Alexander Ratushnyak. A Data Compression mini-FAQ with a good set of links.
Data-compression.com Rate
The title says A website devoted to the principles and practices of data compression. Can’t ask for anything better than that. Appears to be run by Nam Phamdo from SUNY Stony Brook. Links to papers, explanations, and software.
User comment:Gives technical explanations and animated examples of a small number of compression methods. The explanations are good, but the amount of coverage of the field overall is small.
Maxime Zakharov – Compression Links Rate
Compression links to papers and web sites, mostly in Russian language.
Welcome to ItComputing Online Research and Development Resources Rate
A page of links, with a substantial number dedicated to data compression.
Yahoo links to compression companies Rate
Links to companies engaging in commerce related to data compression. A moderate-sized set of links. At last check, in addition to direct listings, contains subtress for Commercial Products, Fractal Compression, and a couple of others.
Secção de Análise de Sinais Rate
A set of links that includes a few data compression sites. This page is from Instituto Superior de Engenharia de Lisboa (a Lisbon Polytechnic school), Portugal, and is in Portuguese. This page contains a link to the Data Compression Group object oriented framework for teaching C++. (Indexed here as The DCG Framework.
Compression des images (et autres documents) Rate
This site has pointers to various sits related to image compression. The entire site is written in French.
Free Compression and Archiving Libraries and Source Code Rate
This web site keeps links to free libraries and source code. If you like this, you might want to browse around in some of their other areas as well.
DataCompression.info user Andrew S. was not too impressed with this site: I tried one half of their links and they were all dead or directed to content not related to the topic.
Data Compression – Definition in the PC Webopedia Rate
The definition also has links to some keyword definitions.
Information Theory Research Group Rate
Home page for John C. Kieffer, Dept. of EE, University of Minnesota. Includes course descriptions for classes on data compression and information theory. The course descriptions have links to some papers.
Yahoo links to compression Rate
A suprisingly sparse set of entries. You would think Yahoo could do better.
Bibliography on Source Coding/Data Compression Rate Mitsuharu Arimura’s page of links and references to a wide variety of papers and books on lossless compression. Some of the links are listed in English, others in Japanese.
Theory of Data Compression Rate A nice overview of the field by Nam Phamdo, slanted a bit towards the academic view but at a very accessible level. Links to important and influential papers.
Pin-Outs Algorithms : Compression Rate This portal site has a page dedicated to compression, plus a number of sub-pages with pointers to companies, researchers, and a few other odds and ends.
Sam’s Compression Links Rate A short list of assorted compression links, no particular theme.
Data Compression Pointers Rate A set of data compression links maintained by Haruhiko Okumura. Many of the links here point to Japanese language sites. Even if you cannot read Japanese, you may still profit from the profusion of links on this page. Just be sure your browser is set to render Shift-JIS.
UCSB Signal Compression Lab Rate Various research areas of some interest in here.
Dr. Sandra Woolley’s Data Compression Linkes Rate An assortment of links on a wide variety of compression related topics. Includes a rating system indicating the value of the links.
Lycos – Computers/Algorithms/Compression/ Rate A page of links on the Lycos portal.
The Compression Site Rate by Dave Kristula. Has download pages for archivers, plus benchmark results.
Data Compression Benchmark Suite Rate A set of links to files that are used to benchmark various data compression algorithms.
The Edge – Archives Rate A huge disordered collection of links, newsgroup posts, and random conversations regarding data compression.
Compression Algorithms Rate A set of links from Softpanorama, the Open Source Software Educational Society. A lot of information on the entire site. The compression links are not as complete, but some interesting stuff here.
AG Information und Komplexität Rate A nice set of links to various resources related to info theory and data compression. German language.
What’s New In Math – October, 2002 – Compression Codes and Technologies Rate The American Mathematical Society runs a monthly column called ‘What’s New In Math,” featuring topics of general interest to their readers. In October 2002, the topic was data compression, which led to a fairly lengthy column with many, many references. Good reading!
Algorithms in the Real World (Guy Blelloch) Rate Guy has a set of slides here that must illustrate a comprehensive set of links about data compression. Includes a link to a PS file containing a sample chapter on algorithms that Guy is writing.
Michael Walden’s Compression Pointers Rate A comprehensive set of compression pointers. Unfortunately, Michael is using some sort of software that makes bookmarking into his index impossible. So instead, you must link to the main page, shown here, and locate the links to “Data Compression”. Under that he has links to General Resources, Software, and Theory.
Oingo’s Compression Algorithms Page Rate Oingo is a human-edited directory, sort of a super-duper search engine.
CiteSeer Compression References Rate CiteSeer tracks references between academic papers, and has links to online versions of a great many papers. The compression links at the top level look like they are a bit sloppy, but there are subcategories for Audio, Text, and Video, which look as though they may be better.
Open Here Compression Algorithms Page Rate The Open Here search engine page dedicate to compression algorithms
EE 5585: Data Compression Rate A collection of class notes and links for a University of Minnesota course on Data Compression.
Mathtools.net DSP/Applications/Compression Page Rate Mathtools.net describes itself as the technical computing portal for all your scientific and computing needs. Perhaps a bit ambitious! Here’s their page links to compression applications.
Google’s Data Compression Algorithm Directory Rate A selection of pointers to web sites that have something to do with data compression algorithms.
AltaVista Compression Links Rate A page of compression links from AltaVista
Delphi Programming – Backup and Data Compression Rate The About.com guide to Delphi Programming has a section on Data Compression and Backup software that looks pretty useful. About.com is a search engine and link site that features pages edited and maintained by real live humans.
Newsgroup Posts

comp.compression FAQ Rate
The official source for the comp.compression FAQ.
David Cary’s Data Compression Links Rate
A huge number of links, thoughts, and documentation on a wide variety of data compression topics.
comp.compression Rate
This newgroup carries a good deal of interesting traffic on data compression. The lack of moderation means the noise level is still fairly high, but the interested reader can find much to enjoy here.
How about an Introduction to data compression? Rate
The comp.compression provides the Cliff Notes version of the question.
alt.comp.compression Rate
This newsgroup doesn’t generate as much compression as its sibling, comp.compression. I know of nothing else that differentiates the two.
The Edge – Archives Rate A huge disordered collection of links, newsgroup posts, and random conversations regarding data compression.
Free Specs from the ITU Rate According to Pete Fraser, you can download three free specifications from the ITU per year, after free registration. This is a great deal – these specs can run into the hundreds of dollars per copy, and if you aren’t near a university library, you may have no other way to get them.
A Fallacy in Model + Encoder Rate Charles Bloom thinks out loud about the canonical model + encoder of contemporary data compression.
Non-Commercial Libraries

ANSI-C Bit Manipulation Libraries Michael Dipperstein has written a few compression programs, which naturally requires that you be able to read and write bits one at a time, and possibly in chunks of other sizes. He has packaged up this capability as a separate library, and makes it available to the world here.
QccPack — Quantization, Compression, and Coding Library Rate
James E. Fowler at Mississippi State University has created this library, which is an open source collection of routines that are useful for people interested in data compression research. The distribution includes QccSPIHT.
Version 0.45 is available as of December, 2003.
DjVu – Next generation image compression technology Rate
DjVu is an image compression technique that is meant to be used on scanned documents. AT&T has created a browser plugin that supports DjVu files. AT&T claims that DjVu files are 5 to 8 times smaller than GIF or JPEG images of similar quality. Some public source code is provided here, but the exciting parts of DjVu are not available.
Update: I believe this project has morphed away from AT&T and into the Open Source World. The AT&T site has been gone since 6/2002, I hope that this represents its new incarnation. I’m also moving the project status from Commercial to Non-Commercial
Source and Executables for the Amiga Rate
A huge selection of compression source and executables for the enigmatic Amiga.. I don’t know if this is a mirror site or independent.
Free Compression and Archiving Libraries and Source Code Rate
This web site keeps links to free libraries and source code. If you like this, you might want to browse around in some of their other areas as well.
DataCompression.info user Andrew S. was not too impressed with this site: I tried one half of their links and they were all dead or directed to content not related to the topic.
Programmer’s Heaven Compression Programs Rate
A really nice set of programs and source code for all sorts of data compression. This area doesn’t appear to be actively maintained, so there are plenty of out-of-date files, but good stuff mixed in as well.
DjVuLibre Rate This is an open-source package of DjVu programs and libraries, including encoders, viewers, browser plugins, and various utlities. The DjVu standard for document encoding was once an ATT research project, but now has been commercialized by LizardTech. This project is an attempt to popularize and evangelize the DjVu technology, with at least the benign awareness of LizardTech.
Release 3.5.13 shipped in April of 2004.
Encrypted Compressed Transfer Protocol Rate This group aims to create a transfer protocol that has the functions of FTP and the advantges of HTTP. The main features will be encryption and compression. Work in progress – if you speak German you can learn more about the project here.
Delphi Skunkworks – Data Compression Rate A page full of links to data compression resources for Delphi Programmers. Mostly libraries.
The Open Compression Toolkit for C++ Rate The Open Compression Toolkit is a set of modular C++ classes and utilities for implementing and testing compression algorithms.
Simple interface and skeleton code for creating new compression algorithms.
Complete testing framework for validating and comparing new algorithms.
Support for algorithms that use external dictionaries/headers.
Utility classes and sample code for bitio, frequency counting, etc.
Non-Commercial Programs

AOL.COM search: Home > Computers > Software > Data Compression Rate
AOL search page with links to commercial and free data compression programs, and the companies that produce them.
DjVu – Next generation image compression technology Rate
DjVu is an image compression technique that is meant to be used on scanned documents. AT&T has created a browser plugin that supports DjVu files. AT&T claims that DjVu files are 5 to 8 times smaller than GIF or JPEG images of similar quality. Some public source code is provided here, but the exciting parts of DjVu are not available.
Update: I believe this project has morphed away from AT&T and into the Open Source World. The AT&T site has been gone since 6/2002, I hope that this represents its new incarnation. I’m also moving the project status from Commercial to Non-Commercial
MG Pages Rate
Some pages that go along with the book “Managing Gigabytes”, by Witten et.al. These pages are devoted to MG, “an open-source indexing and retrieval system for text, images, and textual images.”
Source and Executables for the Amiga Rate
A huge selection of compression source and executables for the enigmatic Amiga.. I don’t know if this is a mirror site or independent.
FEI STU Bratislava,Slovakia,Europe Rate
A very complete archive of compression programs, freeware, shareware, source, archviers, compressors, etc. They have it all. At last count this site has at least 1000 compression downloads
Programmer’s Heaven Compression Programs Rate
A really nice set of programs and source code for all sorts of data compression. This area doesn’t appear to be actively maintained, so there are plenty of out-of-date files, but good stuff mixed in as well.
Stuba mirror site Rate A mirror site for the big compression software site. See 0index.txt for a list of what’s here, an unbelievably large treasure trove.
DjVuLibre Rate This is an open-source package of DjVu programs and libraries, including encoders, viewers, browser plugins, and various utlities. The DjVu standard for document encoding was once an ATT research project, but now has been commercialized by LizardTech. This project is an attempt to popularize and evangelize the DjVu technology, with at least the benign awareness of LizardTech.
Release 3.5.13 shipped in April of 2004.
M5 Online Compression Utility ver 1.0.1 Rate The University of Central Florida has this web page which allows you to upload a file and then compress it using a wide variety of algorithms.
Smile256! Rate A program by Andrew Frolov on a site dedicated to complete programs that are less than or equal to 256 bytes in length.
Complearn Rate Compression is concerned with detecting patterns in order to reduce redundancy. Complearn is an attempt to take that pattern-recognition ability and use it for different ends.
DACT Rate DACT is a brute force compressor written by Roy Keene that tries out a whole library of compression routines on a given file, and then simply picks the best performer.
Release 0.8.36 was shipping in early March, 2004.
Papers/Documentation

“Data Compression Fundamentals” (1998) Andrey Fomin has posted a long Russian paper in word format on his web site. You’ll need a Microsoft Passport (free) to get here, but it’s worth the trip if you can read it.
Andrey has this to say about his paper/book: A survey of different basic Data Compression techniques. Uses some mathematical and statistical materials, but doesn’t require a special scientific degree. Though written in Russian, this book contains VERY useful References, Examples and Source Codes!
Mark Nelson’s Articles Mark Nelson’s magazine articles, including articles on LZW coding, arithmetic coding, Zlib, and JavaZip.
Mark Nelson Mark Nelson’s home page, with links to his books and articles.
Kompressionsalgorithmen Rate
A big survey paper of data compression techniques by Joachim Schwarz und Guido Sörmann. German language.
David Pereira Coutinho Rate
Personal page of David Pereira Coutinho, Professor at Instituto Superior de Engenharia de Lisboa. This page contains links to several compression-related abstracts and papers, as well as links to the Data Compression Framework developed with his students. (Indexed here as The DCG Framework.) The majority of the page is available in English and Portuguese.
The New Zealand Digital Library Rate
A tremendous selection of computer science papers, pulled in from over one thousand different CS bilbiographies. Although this page doesn’t specifically relate to data compression, it has plenty to offer the interested researcher.
Digging Deep Into Compression Rate
An article in Wired that talks about the use of compression for patten recognition. Tools as simple as Zip are able to accurately determine the language of a given text. More complex algorithms are being used to determine matches of DNA sequences.
Charles Bloom’s Page Rate
Charles has a really great collection of software he has written on this page, much of it is indexed here in the appropriate pages. His home page also contains links to some interesting papers and descriptions on various algorithms, as well as some archived posts that explain some compression topics. It’s well worth nosing around this site a bit for more information.
Jeff Vitter’s Recent Papers Rate
Jeff Vitter is a publishing machine. A substantial subset of is work deals with data compression and/or information theory. On top of all that, he’s good enough to keep most of his work online in ps and pdf format.
Papers of Antonio Ortega Rate
Antonio Ortega at USC has quite a few compression related papers on line. They include papers on wavelets and quantization.
Data Compression Conference 2000 – Proceedings Rate
All of the papers from the 2000 Data Compression Conference are available here on line.
Data Compression Conference 1999 – Proceedings Rate
All of the papers from the 1999 Data Compression Conference are available here on line. Yes, there is a catch – you will have to pay if you want to do more than read the abstract. (Looks like a strong incentive to become a member of the IEEE Computer Society.)
Data Compression Conference 1997 – Proceedings Rate
All of the papers from the 1997 Data Compression Conference are available here on line.
Data Compression Conference 1998 – Proceedings Rate
All of the papers from the 1998 Data Compression Conference are available here on line.
Data-compression.com Rate
The title says A website devoted to the principles and practices of data compression. Can’t ask for anything better than that. Appears to be run by Nam Phamdo from SUNY Stony Brook. Links to papers, explanations, and software.
User comment:Gives technical explanations and animated examples of a small number of compression methods. The explanations are good, but the amount of coverage of the field overall is small.
Steve Tate Rate
Home Page for Steve Tate, University of North Texas. State Tate is an Associate Professor at the University of North Texas, and has links to a few data compression papers on his site.
Ioannis Kontoyiannis Rate
Ioannis Kontoyiannis is an Assistant Professor at Purdue. He has many of his papers available on line, in PS or PDF format, often both. Sample title: Pointwise redundancy in lossy data compression and universal lossy data compression..
Non-US Data Compression and Coding Research Rate R.M. Gray (Ed.), M. Cohn, L.W. Craver, A. Gersho, T. Lookabaugh, F. Pollara, and M. Vetterli, November 1993. A Foreign Applied Sciences Assessment Center (FASAC) report prepared for Science Applications International Corporation (SAIC) under U.S. Government sponsorship. This is the draft version in Poscript format submitted to SAIC.
Data Compression in Japan Rate I need a translation of this page from any interested volunteer.
Unknown Rate I need a translation of this page from any Japanese speaking volunteers.
Juergen Schmidhuber’s Publications Rate Juergen writes a lot of papers. Lots and lots of papers. Looks like lots of stuff on neural nets and the like.
CMPE 263 Handouts by Glen Langdon Rate A set of handouts for a survey course on Data Compression, inlcuding papers on various types of coding, information theory, and more. An academic approach to the topics but quite accessible.
Latest Publications from UCF Rate Latest compression papers here. When this site was first crawled, the papers covered a wide variety of topics in both lossless and lossy compression.
Léon Bottou’s Publications Rate Léon has a very nice set of publications online here, generally in both DjVu and PS format. A total of 45 papers with titles such as “Managing drift in DCT-based scalable video coding” and “DjVu : Analyzing and Compressing Scanned Documents for Internet Distribution.”. Bless those who make their work available to the world on the Internet!
Multimedia Paper Summaries Rate A set of links to paper summaries, including a batch on Coding, Compression, and Media Formats.
ACM Crossroads Spring 2000 Issue – Data Compression Rate Crossroads is the student publication of the ACM. This issue concentrates on data compression, and includes several very worthwhile articles.
CiteSeer Compression References Rate CiteSeer tracks references between academic papers, and has links to online versions of a great many papers. The compression links at the top level look like they are a bit sloppy, but there are subcategories for Audio, Text, and Video, which look as though they may be better.
DjVu Technical Papers Rate This page has a number of papers related to the DjVu compression format. Papers are all posted in ps.gz and DjVu formats. Note that you’ll need the DjVu plugin to read them in that format.
Patents/Licenses

What about patents on Data Compression algorithms? Rate
The comp.compression FAQ attempts to shed some light on this topic.
Compression Patents Sorted By Coverage Rate Ross Williams has provided a list of compression patents here. Might help, although the site is a few years old and doesn’t appear to have been updated recently.
People

Mark Nelson Mark Nelson’s home page, with links to his books and articles.
David Pereira Coutinho Rate
Personal page of David Pereira Coutinho, Professor at Instituto Superior de Engenharia de Lisboa. This page contains links to several compression-related abstracts and papers, as well as links to the Data Compression Framework developed with his students. (Indexed here as The DCG Framework.) The majority of the page is available in English and Portuguese.
Alistair Moffat Rate
Alistair Moffat’s home page. Alistair is one of a cluster of antipodal data compression mavens, currently working in Melbourne, Australia. This page has a link to some copies of abstracts and papers.
Tim Bell’s home page Rate
Tim Bell is one of the many compression mavens in Australia and New Zealand. This page contains links to many of his ongoing projects.
David Salomon’s home page Rate
Mr. Salomon is the author of Data Compression: The Complete Reference.
James Storer’s home page Rate
James Storer chairs the annual DCC event, and keeps busy in many other areas. Back in the bygone era his book on Data Compression had a lock on the market. See what he’s been up to lately here.
Giovanni Manzini Rate
Giovanni Manzini has published papers covering a few different topics in Data Compression, including several recent works on Burrows-Wheeler algorithms. He is currently an Associate Professor of Computer Science at the Universita degli Studi del Piemonte Orientale in the the most northern reaches of Italy.
Ross Williams Rate
Ross Williams did some seminal work in the area of dictionary based encoders in the late 1980s and early 1990s. His LZRW algorithms were not only innovative and interesting, but they managed to place Ross right in the middle of some early software patent issues.
Leonid A. Broukhis’ home page Rate
I don’t know the native language being used here, although it appears to be using perhaps a Cyrillic alphabet.
Steve Tate Rate
Home Page for Steve Tate, University of North Texas. State Tate is an Associate Professor at the University of North Texas, and has links to a few data compression papers on his site.
Paolo Ferragina Rate
Paolo Ferragina’s research in data structures and string matching naturally lends itself to Data Compression and to the problem of indexing compressed data. See the link to his recent papers on indexing BWT compressed files. He is currently an Associate Professor of Computer Science at the University of Pisa.
Ioannis Kontoyiannis Rate
Ioannis Kontoyiannis is an Assistant Professor at Purdue. He has many of his papers available on line, in PS or PDF format, often both. Sample title: Pointwise redundancy in lossy data compression and universal lossy data compression..
Jeff Vitter Rate Email address for Jeff Vitter, prolific author of papers which frequently include data compression topics
Professor John G. Cleary Rate One of the many academics interested in data compression at University of Waikato in New Zealand. Cleary has been involved in many important developments in the field.
Compression Register Rate A register of companies, people, and institutes having something to do with data compression.
High School Kids Win Prizes for Compression Algorithm Rate A couple of high school kids from Saratoga, CA, were regional winners in the Siemens Westinghouse Science and Technology competition.
Jeff Vitter Rate Home page for Jeff Vitter, prolific author of papers which frequently include data compression topics.
Ian H. Witten Rate Ian H. Witten’s Home Page. I’m Professor of Computer Science here in sunny New Zealand — Department of Computer ScienceUniversity of Waikato, New Zealand
AOL.COM search: Home > Computers >Algorithms > Compression > Researches Rate AOL’s search page keeps a list of folks who are active researchers in the field of compression.
OpenHere – Compression Researchers Rate The OpenHere search engine’s page listing people involved with compression.
Slashdot Interview With Jean-loup Gailly Rate Jean-loup talks about Llinux, data compression, patents, and more.
Data Compression Researchers Rate The page from the Google directory.
Portuguese

David Pereira Coutinho Rate
Personal page of David Pereira Coutinho, Professor at Instituto Superior de Engenharia de Lisboa. This page contains links to several compression-related abstracts and papers, as well as links to the Data Compression Framework developed with his students. (Indexed here as The DCG Framework.) The majority of the page is available in English and Portuguese.
Secção de Análise de Sinais Rate
A set of links that includes a few data compression sites. This page is from Instituto Superior de Engenharia de Lisboa (a Lisbon Polytechnic school), Portugal, and is in Portuguese. This page contains a link to the Data Compression Group object oriented framework for teaching C++. (Indexed here as The DCG Framework.
Results

A Corpus for the Evaluation of Lossless Compression Algorithms Rate Ross Arnold and Tim Bell, “A Corpus for the Evaluation of Lossless Compression Algorithms”, Proc. IEEE Data Compression Conference, Snowbird, Utah, March 1997.
Russian

“Data Compression Fundamentals” (1998) Andrey Fomin has posted a long Russian paper in word format on his web site. You’ll need a Microsoft Passport (free) to get here, but it’s worth the trip if you can read it.
Andrey has this to say about his paper/book: A survey of different basic Data Compression techniques. Uses some mathematical and statistical materials, but doesn’t require a special scientific degree. Though written in Russian, this book contains VERY useful References, Examples and Source Codes!
Data Compression Site Rate
This site is in Russian, so I am not able to tell you much about it. It has links to some papers, and seems to have a link to PDF files that comprise much of a book on compression.
Reader Dan L. says The best site about comression!
Maxime Zakharov – Compression Links Rate
Compression links to papers and web sites, mostly in Russian language.
Source Code

QccPack — Quantization, Compression, and Coding Library Rate
James E. Fowler at Mississippi State University has created this library, which is an open source collection of routines that are useful for people interested in data compression research. The distribution includes QccSPIHT.
Version 0.45 is available as of December, 2003.
MG Pages Rate
Some pages that go along with the book “Managing Gigabytes”, by Witten et.al. These pages are devoted to MG, “an open-source indexing and retrieval system for text, images, and textual images.”
Source and Executables for the Amiga Rate
A huge selection of compression source and executables for the enigmatic Amiga.. I don’t know if this is a mirror site or independent.
Introduction to MMX Programming Rate
An article that gets into the details you need to know about in order to use the MMX instruction set found on Intel processors. The author uses image processing as a demo app.
Free Compression and Archiving Libraries and Source Code Rate
This web site keeps links to free libraries and source code. If you like this, you might want to browse around in some of their other areas as well.
DataCompression.info user Andrew S. was not too impressed with this site: I tried one half of their links and they were all dead or directed to content not related to the topic.
Lossless Data Compression Toolkit Rate
Version 1.1 of the lossless data compression toolkit by Nico deVries. The C sources in this toolkit include an LZW compressor, AR002 archiver, a PPM like compressor using arithmetic compression, Huffman compressor, splay tree program, and LZRW1. Quite a variety.
Programmer’s Heaven Compression Programs Rate
A really nice set of programs and source code for all sorts of data compression. This area doesn’t appear to be actively maintained, so there are plenty of out-of-date files, but good stuff mixed in as well.
Maxcode Archive Download Page Rate Maxcode has a selection of C/C++ code here related to archiving and compression.
Source Coding Matlab Toolbox Rate John Kieffer from the University of Minnesota has posted a nice library of Matlab code to be used for data compression.
The Open Compression Toolkit for C++ Rate The Open Compression Toolkit is a set of modular C++ classes and utilities for implementing and testing compression algorithms.
Simple interface and skeleton code for creating new compression algorithms.
Complete testing framework for validating and comparing new algorithms.
Support for algorithms that use external dictionaries/headers.
Utility classes and sample code for bitio, frequency counting, etc.
Mathtools.net Compression Page Rate Mathtools.net describes itself as the technical computing portal for all your scientific and computing needs. Perhaps a bit ambitious! Here’s their page with C++ compression links.
Standards

Free Specs from the ITU Rate According to Pete Fraser, you can download three free specifications from the ITU per year, after free registration. This is a great deal – these specs can run into the hundreds of dollars per copy, and if you aren’t near a university library, you may have no other way to get them.
Tutorials, Reference, Presentations

Mark Nelson’s FAQ This contains pointers to some of the frequently asked questions that I receive. Many are related to data compression.
Mark Nelson’s Articles Mark Nelson’s magazine articles, including articles on LZW coding, arithmetic coding, Zlib, and JavaZip.
Mark Nelson Mark Nelson’s home page, with links to his books and articles.
A Data Compression Primer Rate
A short tutorial on a few basic data compression concepts.
comp.compression FAQ Rate
The official source for the comp.compression FAQ.
Charles Bloom’s Page Rate
Charles has a really great collection of software he has written on this page, much of it is indexed here in the appropriate pages. His home page also contains links to some interesting papers and descriptions on various algorithms, as well as some archived posts that explain some compression topics. It’s well worth nosing around this site a bit for more information.
David Cary’s Data Compression Links Rate
A huge number of links, thoughts, and documentation on a wide variety of data compression topics.
EE 5585 Home Page Rate
A collection of class notes, homework assignments, and links for a class on Data Compression at the University of Minnesota.
What is Compression? Rate
An explanation from Colin E. Manning, complete with pictures.
The Green Tree Of Compression Methods Rate
A Practical Introduction To Data Compression by Alexander Ratushnyak. A Data Compression mini-FAQ with a good set of links.
Data Compression from The Scientist and Engineer’s Guide to Digital Signal Processing Rate
A sample chapter from The Scientist and Engineer’s Guide to Digital Signal Processing, which just happens to be on Data Compression. You can download this entire book for free from the web site.
However, if you wish to purchase the hardcopy, please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Introduction to MMX Programming Rate
An article that gets into the details you need to know about in order to use the MMX instruction set found on Intel processors. The author uses image processing as a demo app.
Data Compression Algorithms Rate
by Jeffrey N. Ladino. His description of the page: This page is a research project in the field of data compression algorithms. It is intended to be an informative overview for a beginner in the field of computer science. Mostly talks about lossless compression, with an explanation of Huffman coding.
Data Compression – Definition in the PC Webopedia Rate
The definition also has links to some keyword definitions.
The Data Compression Reference Center Rate
A site that provides some good pages discussing various fundamental aspects of Data Compression. Although the site appears to be a university project in Croatia, all of the pages are writen in English. This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Theory of Data Compression Rate A nice overview of the field by Nam Phamdo, slanted a bit towards the academic view but at a very accessible level. Links to important and influential papers.
Codec capers – The inaudible mystery of the missing bits Rate An article from CommVerge giving a little bit of an overview about data compression using various audio compressors. Two follow-up articles are linked to from this page.Registration required
Interactive Data Compression Tutor Rate An interactive introduction to Data Compression. Covers lossless methods.
Data Compression: Bits, Bytes, and Beefalo Rate by Walter Korman. An introductory article with a very brief look at the field, along with some links.
Compression Algorithms Rate This page has links to a bunch of algorithm descriptions, courtesy of the Data Compression Reference Center. This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
How File Compression Works Rate The How Stuff Works web site tackles the question of just how Data Compression works, pitched to the general audience. All in all not a bad stab at it, with links to may other How Stuff Works pages for the curious.
File Compression: New Tool for Life Detection? Rate Researchers looking for signs of life have decided that complexity might be a good indicator. What better to measure complexity than gzip?
What’s New In Math – October, 2002 – Compression Codes and Technologies Rate The American Mathematical Society runs a monthly column called ‘What’s New In Math,” featuring topics of general interest to their readers. In October 2002, the topic was data compression, which led to a fairly lengthy column with many, many references. Good reading!
Algorithms in the Real World (Guy Blelloch) Rate Guy has a set of slides here that must illustrate a comprehensive set of links about data compression. Includes a link to a PS file containing a sample chapter on algorithms that Guy is writing.
Hacking Data Compression Rate Andy McFadden was nice enough to post a series of a dozen lessons on Data Compression. It looks as though these were posts to the now-forgotten GEnie information service, once a pretender to the CompuServe popularity crown.
Data Compression – Systematisation Rate T. Strutz offers up an overview and taxonomy of Data Compression. If you’re looking for the big picture, this might be a good place to start. A PowerPoint presentation is available for download as well – might be just the thing if you only have an hour left to prepare that lecture!
Wikipedia Entry: Data Compression Rate The Wikipedia entry for the topic of Data Compression. Many links to other Wikipedia entries on this page, including MP3, JPEG, Fractal compression, etc.
Some Summary Rate This web page explains a proposed categorizaton of various data compression methods.
EE 5585: Data Compression Rate A collection of class notes and links for a University of Minnesota course on Data Compression.
Compression, Encoding and Graphics Files – A Practical Tutorial Rate Tutorial by Rich Holowczak from Rutgers U. A set of slides that would probably be really useful if you had the lecture to go with it. Without the lecture, not so hot.
How File Compression Works Rate An article pitched to the layman on how compression works.
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Esoterica/Miscellany

Miscellaneous and esoteric stuff that doesn’t fit anywhere else.
Commercial Libraries

WSQ by Aware Rate
WSQ by Aware is our implementation of the Federal Bureau of Investigation’s Wavelet Scalar Quantization fingerprint compression standard. WSQ by Aware is the industry’s highest performing implementation of the FBI’s Wavelet Scalar Quantization (WSQ) digital fingerprint compression algorithm. WSQ is a wavelet transform-based compression standard, developed by the FBI for compression of digital fingerprint images.
GAO Research Modem Software Rate GAO Research sells modem software for quite a few different platforms, including a big batch of DSP parts. Naturally, this includes modules to perform both V.42bis and V.44 data compression.
ProGATE Rate Enbaya makes a product called ProGATE that is used to compress 3D graphics and animations for game developers.
Commercial Programs

ZFilter Rate
ZFilter is the ZIP indexing filter for SharePoint, Internet Information Server, Site Server and Microsoft Exchange server. ZFilter is a library that handles .zip archives and returns indexable text and value properties in a similar way to the MS Office filter and the PDF filter supplied by Adobe. The library handles all zip archives created with WinZip, PKWare and DynaZip, indeed any archive created using the compression format based on PKWare.
Satisfied DataCompression.info user Jim R. had this to say:I’ve been searching high and low for exactly this thing for years, and now I’ve found it, and it works.
SoftDefender Rate
Soft Defender is a good exe file compressor, which can reduce the file size of 32-bit Windows programs by as much as 50%.In addition, Soft Defender is a perfect product of software protection of applications.With Soft Defender, your application can have anti-debugging, anti-tracer, anti-disassemble, anti-dumping, anti-apihook, file integrity checking functions in seconds. It requires no source code editing or your registration algorithm changing.
CHAOS Self Extractor Rate
CHAOS Self-Extractor is a utility program that creates self-extracting ZIP files for Windows. CHAOS supports a form of encryption that it claims is much stronger than standard Zip encryption.
DWG2ZIP Rate
This program lets you compress AutoCad DWG files into Zip archives for distribution.
Version 2.0 is shipping as of May, 2003.
JAM ™ Version 1.25 Rate
JAM is a transparent hard disk compressor, which enlarges your disk space. With the JAM you will forget about annoying messages like ‘Insufficient disk space…’ with no need to purchase a new hard disk.
GZIPSite Rate GZIPSite is a tool that can compress your web site and allow it to load as much as 50% faster.
ZipSearch Rate A search program for Win32 computers. ZipSearch knows how to look through Zip files and compressed EXEs to find search strings.
Version 1.07 shipping in December, 2002.
AM-Zip Rate Lots of folks (including me) perform system backups into Zip archives. Over the years I became leery of proprietary formats used by various manufacturers of tape drives, removable disks, etc. Zip files give me a much better feeling, and make it a lot easier to browse through my backups. Martin Aignesberger must feel the same way, because he has created a product that performs daily backups into Zip files. This is a commercial product, but he does offer a 30 day free evaluation.
Rarissimo Rate Rarissimo is a file utility to automatically compress and/or uncompress files, companion for the award winning compression program WinRAR. Distinguishable from other compression solutions by its ability to fully preserve NTFS alternate streams. This feature provides automatic compression/uncompression for Macintosh files stored on NT volumes preserving their filenames and peculiar structures – it means for example that you can use Rarissimo to send and receive Macintosh files using any standard FTP process (and not only Mac-based programs).
DataCompression.info user Marie M. said: This utility is very specialized so not easy to find. It is a great help to transfer Mac files without a special Mac ftp utility.
PDFCompress Rate A Mac OS X utility to shrink the huge PDF files created by the Mac Quartz rendering engine.
LuraDocument.jpm PdfCompressor Rate The LuraDocument.jpm PdfCompressor is a Windows application that can be used to automatically (Server version) or manually convert scanned documents to higly compressed PDF files. The supported input formats are TIFF, JPEG, BMP and PNM.
Ultimate ZIP Cracker Rate A program designed to crack lost passwords for zip and arj files.
Absolute HTML Compressor Rate Absolute HTML Compressor is an award-winning tool that optimizes HTML files so that their size is reduced.
CHM2PDF Pilot Rate Convert your CHM help files from Microsoft to Adobe’s PDF format. This is shareware that runs on Win32 platforms.
Companies/Organizations

Cal Tech improves on 3D compression Rate CNN reports on a research team at Cal Tech that has created a new algorithm for compressing 3D object representations. If you can figure out how it works from this article, send me an email!
Zip Programs Can Identify Language Of Any Document Rate A couple of researchers from Rome have shown that adaptive compression algorithms can be used to accurately predict the language of the source text.
French

Rarissimo Rate Rarissimo is a file utility to automatically compress and/or uncompress files, companion for the award winning compression program WinRAR. Distinguishable from other compression solutions by its ability to fully preserve NTFS alternate streams. This feature provides automatic compression/uncompression for Macintosh files stored on NT volumes preserving their filenames and peculiar structures – it means for example that you can use Rarissimo to send and receive Macintosh files using any standard FTP process (and not only Mac-based programs).
DataCompression.info user Marie M. said: This utility is very specialized so not easy to find. It is a great help to transfer Mac files without a special Mac ftp utility.
Hardware

IBM research breakthrough doubles computer memory Rate IBM has created a chip that appears to be able to dynamically compress data as it is being written to RAM. Details sketchy in this news release.
Italian

C Library to search over compressed texts Rate
A team from the University of Pisa in Italy have created a set of two libraries to demonstrate the ability to perform searches in compressed text. The code is packaged as two LGPL libraries: HuffwLib and CGrepLib, and sample programs are available on the site for demonstration purposes.
Links

One to One Compression This site discusses a characteristic of some compression algorithms that the author refers to as One to One compression. In a nutshell, this property means that for any file X, F( F'( X ) ) == X. (F is either the compressor or decompressor, and F’ is its opposite number.) This is definitely not the case for most conventional compression algorithms.
Pattern Matching Pointers Rate
A really nice set of links to people and resources related to pattern matching. This is a great general purpose page of links, but only lightly grazes the data compression world.
Cognition as Compression Rate
Cognition as Compression, by Gerry Wolff, discussion of the author’s research.
From as long ago as the last century it has been recognised that information processing in brains and nervous systems (perception, learning, thinking, neuro-muscular control etc) may be governed by principles of economy or compression.

Cyclic Redundancy Check Rate
The definition from the NIST Dictionary of Algorithms and Data Structures.
3DCompression.com Rate A directory of links and resources on compressing the 3D models used for computer graphics and other large geometric datasets. This is a replacement for the site at http://www.cc.gatech.edu/~kingd/3Dcompression.html.
Mathtools.net – C/C++ Random Numbers Rate Links to code and tools to create random numbers. Quite useful, and includes some intriguing use of sound cards to provide true (instead of psuedo-random) numbers. Registration required.
Newsgroup Posts

comp.dcom.fax FAX FAQ Rate This article contains the answers to some Frequently Asked Questions (FAQ) often seen in the USENET newsgroup comp.dcom.fax relating to facsimile standards, software, and hardware. Most importantly, contains an explanation of FAX encoding.
Compression as the God of Science Rate Ramblings from a true believer.
Notes on Low-N Quantum Information Theory Rate Charles Bloom thinks about quantum information theory.
CRC Pointers Rate Somebody posting as thewhizkid complained to the comp.compression newsgroup that he just couldn’t figure out how to do a CRC calculation. He got a couple of good pointers here, including one to the zlib code, and another including a bit of Java that could do the job. I’ll add a pointer to my ancient-but-still-cogent article from DDJ, File Verification Using CRC to the mix. Between the three choices, I hope the poster was able to get a handle on the mysterious CRC.
Non-Commercial Libraries

C Library to search over compressed texts Rate
A team from the University of Pisa in Italy have created a set of two libraries to demonstrate the ability to perform searches in compressed text. The code is packaged as two LGPL libraries: HuffwLib and CGrepLib, and sample programs are available on the site for demonstration purposes.
The Open Compression Toolkit for C++ Rate The Open Compression Toolkit is a set of modular C++ classes and utilities for implementing and testing compression algorithms.
Simple interface and skeleton code for creating new compression algorithms.
Complete testing framework for validating and comparing new algorithms.
Support for algorithms that use external dictionaries/headers.
Utility classes and sample code for bitio, frequency counting, etc.
UnicodeCompressor : another alphaworks technology Rate IBM has developed a pair of Java clases that compress Unicode according to the Standard Compression Scheme for Unicode. Looks like they might be giving it away here.
Encrypted Compressed Transfer Protocol Rate This group aims to create a transfer protocol that has the functions of FTP and the advantges of HTTP. The main features will be encryption and compression. Work in progress – if you speak German you can learn more about the project here.
NX Developers Rate This site appears to the home page for a project dedicated to developing an Open Source X Windows compression library.
MFFM Bit Stream Rate A C++ hierarchy that is designed to efficiently read and write bit streams. Needless to say, this is quite useful for compression programs.
Version 1.0 shipped in December, 2003.
CRC Encoding Rate Marcel de Wijs has written an article on creating CRC codes in C#.
jpg2html Rate jpg2html converts JPEG images into HTML. A series of jpg2html procedures are being written to explore different means and different effects.
Non-Commercial Programs

Vidfern Squeezer Rate
Squeezer is another executable compressor for Windows, and it’s now free. Here’s what you’ll read on the Vidfern web site:
Vidfern Squeezer as the best file compressor, can squeeze executable files as well as text and HTML files. Get more space by squeezing your files! Squeezer is now free for personal and commercial use. It is fully functional, easy and powerful.

Reader Vali from the jp TLD said Thanks to all who create this real good product. I found it a very nice and easy compressor that supports exe, html and text files freely!
BICOM – BIjective COMpressor Rate
BICOM is a freely available open source compressor. It uses a souped-up PPM algorithm, and is completely bijective.
Reader comment: Wow this is hot! …a bijective compressor using full size Rijndael encryption…
David A. Scott’s Fully Bijective Arithmetic Coder Rate
The term bijective as used by Scott means that for any given given file X you are guarantted that A( B( X ) ) == B( A( X ) ) == X, where A and B are a pair of bijectively matched programs. In this particular case, A and B are a compressor and decompressor that use arithmetic coding. Includes C++ source.
KeyCHW: A Compression Utility for MSDN Rate A console mode program that compresses CHW files. This is the type of file used in some help files distributed for Windows applications.
SQUASHFS – A squashed read-only filesystem for Linux Rate Squashfs is a highly compressed read-only filesystem for Linux (kernel 2.4.x). It uses zlib compression to compress files, inodes and directories. Inodes in the system are very small and all blocks are packed to minimise data overhead. Block sizes greater than 4K are supported up to a maximum of 32K.
Release 2.0 of squashfs shipped in May, 2004.
Text In A Zip Rate This unique free program searchs through all your zip files looking for specific strings in specific file types.
PackWord Rate PackWord can compress a Microsoft Word document (.doc) file into a smaller, compressed, .doc file. The compressed .doc file is self-extracting: when loaded into Microsoft Word, the compressed document will automatically expand to the original version.
Xdelta Rate Xdelta is a complete system for managing delta-compressed storage and network transport. Using the Xdelta system, you can easily incorporate this functionality into your application.
Remote Sessions with NX Rate NxServLiv allow compressed remote X sessions using NoMachine’s NX oss libraries. Like ssh terminal but graphical. Work from Modem to Lan with different compression ratios
S3TC-BOXEN: A simple S3TC texture compression tool Rate This product advertises itself as a simple S3TC texture compression tool. The description says that it loads an image file into your video card’s RAM, then instructs the video card to compress it.
Word Replacing Transform Rate A pre-compression transform by Przemyslaw Skibinski, somewhat along the lines of Star Encoding.
Version 3.0 of this program is shipping as of February, 2004.
DMSDOS – Linux kernel driver Rate DMSDOS is a loadable module for the Linux kernel. It provides read and write access to compressed FAT filesystems, such as Microsoft’s Doublespace/ Drivespace and Stac’s Stacker.
Caliph and Emir Rate Java & MPEG-7 based tools for semantic annotation and retrieval of digital photos and images supporting graph like annotation and content based image retrieval.
Zlibc Rate Zlibc emulates a compressed file system. This lets you keep all your executables compressed in one place, unzipping them on the fly as they are needed. Looks like it works with various Linux and UNIX type sytems, including Solaris. I’m guessing that it’s free, please correct me if I’m wrong.
Complearn Rate Compression is concerned with detecting patterns in order to reduce redundancy. Complearn is an attempt to take that pattern-recognition ability and use it for different ends.
GetCRC Rate This instructive program creates a wide variety of 16 and 32 bit CRCs, many of which are commonly used in archiving programs. View the README in the same directory of the ftp server.
mod_zipvfs Rate mod_zipvfs is an Apache2 module, that gives the httpd server the ability to read and browse zipped archives and allows traversal of their content like a virtual filesystem. It is very useful for browsing large html-based documentation without need of decompressing.
DACT Rate DACT is a brute force compressor written by Roy Keene that tries out a whole library of compression routines on a given file, and then simply picks the best performer.
Release 0.8.36 was shipping in early March, 2004.
diffball Rate A general delta compression/differencing suite for any platform that supports autoconf/automake, written in C, w/ builtin support for reading,writing, and converting between multiple file formats.
CleanZipAndGo Rate This is a somewhat unique utility that will only be useful to those of you working on Visual Studio programming projects. Running it erases all your temporary project files, then zips up all the leftovers so you can backup your work.
Deltup Rate This program is designed to accurately create a difference file between two packages, allowing for an update with a minimal source file.
Zip/JPEG Mask and Encryption Rate This cool program uses either Zip file or JPEG file to encrypt some of your data. I think it’s free, email me if I’m wrong.
PDF Compress Rate Free PDF Compressor that removes duplicate PDF objects, optionally takes advantage of new compression features of latest PDF specification (1.5), and optionally takes advantage of a new proposed format called “Compact PDF” that for many classes of documents compresses 30 – 60% better than what is possible in PDF 1.5.
Note: Navigate up two levels to get to Tom’s download page.
Version 2.2 is shipping as of February, 2004.
Papers/Documentation

Woontack Woo – Publications Rate
Woontack Woo has published quite a few papers dealing with coding and compression of stereo images. This is one of the few places you can find information on this somewhat esoteric subject.
Xmill paper Rate
A technical paper describing the principles behind Xmill, the AT&T package that compresses XML data items.
Xmill – An Efficient Compressor for XML Rate
Those folks at AT&T have developed a compressor that can be used to squeeze individual data items in XML documents. AT&T says this is “essentially free” software. Read the license on-line to determine exactly what that means.
Digging Deep Into Compression Rate
An article in Wired that talks about the use of compression for patten recognition. Tools as simple as Zip are able to accurately determine the language of a given text. More complex algorithms are being used to determine matches of DNA sequences.
Data Compression and Encryption Algorithms Rate
Douglas W. Jones, University of Iowa Department of Computer Science. This page contains some C source for a Splay Tree algorithm.
Neural Network Text Compression Programs and Papers Rate
A couple of programs using neural networks for compression, along with a couple of papers by the author. This area of data compression is definitely underserved, check out what’s here and see if neural networks deserve more attention than they are getting.
Update: This page appears to now have some links to general lossless benchmarking info.
Cognition as Compression Rate
Cognition as Compression, by Gerry Wolff, discussion of the author’s research.
From as long ago as the last century it has been recognised that information processing in brains and nervous systems (perception, learning, thinking, neuro-muscular control etc) may be governed by principles of economy or compression.

Computing as compression : The SP Theory and the SP System Rate
Computing as Compression: The SP Theory and the SP System, by Gerry Wolff, discussion of research in progress.
Language Learning as Compression Rate
Language Learning as Compression, discussing the Author’s current research in this area
Compression neural networks for feature extraction: Application to human recognition from ear images Rate This master’s thesis is available in PS format here. The abstract entry is in English, the Postscript document is in Spanish.
Data Compression Newsletter #18 – Bijective Coding Rate This issue of the DDJ newsletter talks about bijective coding, a coding technique that is fearlessly promoted by David Scott, a regular presence in comp.compression.
Binary Delta Compression Rate From Microsoft: This document describes Binary Delta Compression (BDC) technology and its use in software update deployment. This implementation of BDC technology developed by Microsoft reduces the download size of software update packages by downloading only the differences between old files and new files.
Estimating entropy rates with Bayesian confidence intervals Rate I’m pleased to announce with my co-authors availability of a preprint on our new algorithm to estimate the Shannon entropy rate (bits/symbol) or (bits/sec) of an observed sequence of low-alphabet symbols. It uses the Context-Tree-Weighting universal compression method, but doesnot use the compression ratio directly as an entropy estimator but as a scaffold for a Bayesian estimate. The result is significantly lower bias.
Learning Random Networks for Compression of Still and Moving Images Rate A paper describing the use of neural networks to do image compression.
Autosophy Information Theory Rate Klaus Holtz has some interesting ideas about compression theory.
Publications of Christopher M. Brislawn Rate This ftp site has copies of a number of papers by Christopher M. Brislawn. They include various ocuments on the FBI fingerprint compression standard, and a copy of the standard itself.
Compresssion Algorithms and Applications to Genetic Sequence Analysis Rate PhD thesis by Éric Rivals.
Juergen Schmidhuber’s Publications Rate Juergen writes a lot of papers. Lots and lots of papers. Looks like lots of stuff on neural nets and the like.
Optimized Morse Armor Rate John Savard develops an algorithm for optimally encoding messages when forced to use nothing but Morse code.
Progressive Geometry Compression Rate by Andrei Khodakovsky, Peter Schröder, Wim Sweldens. Compressing 3-D object representations is a good thing. Even better is allowing progressive display of these objects. The techniques in this paper are to be applied to geometric meshes.
Efficient Creation of Finite State Automota Rate This paper describes a method which creates minimal acyclic deterministic FSAs. These can be used to create an efficient representation of a dictionary of words by merging identical subtrees.
Sequitir – inferring hierarchies from sequences Rate SEQUITUR is a method for inferring compositional hierarchies from strings. It detects repetition and factors it out of the string by forming rules in a grammar. The rules can be composed of non-terminals, giving rise to a hierarchy. It is useful for recognizing lexical structure in strings, and excels at very long sequences.
Algorithms for Triangulated Terrains Rate by Marc van Kreveld. This paper looks at a method for compressing geographical elevation data.
English Text Frequencies Rate This page has some data on frequencies of words and letters in English text.
Fast Exponentiation Using Data Compression Rate Given the title, this paper has something to do with data compression. But I sure don’t get it.
People

The $5000 Compression Challenge Rate
Patrick Craig has an interesting tale to tell. Without being a data compression expert, he managed to beat the $5000 compression challenge. You won’t see him taking an ocean cruise with his winnings, though. DCL reader commented: The challenge was obviously met.
Data Compression Newsletter #18 – Bijective Coding Rate This issue of the DDJ newsletter talks about bijective coding, a coding technique that is fearlessly promoted by David Scott, a regular presence in comp.compression.
Source Code

Huffman Coding with Priority Queues This article is really about using the priority queue containers that are part of the standard C++ library. The example program implements a Huffman Encoder using the queues, showing how they can do a fairly complex piece of work without too much coding on your part.
Xmill – An Efficient Compressor for XML Rate
Those folks at AT&T have developed a compressor that can be used to squeeze individual data items in XML documents. AT&T says this is “essentially free” software. Read the license on-line to determine exactly what that means.
Compressing Sparse Matrices Rate
Some pseudo-code describing a way to maintain sparce matrices.
Data Compression and Encryption Algorithms Rate
Douglas W. Jones, University of Iowa Department of Computer Science. This page contains some C source for a Splay Tree algorithm.
Trie-based dictionary program Rate
Falk Hueffner created a dictionary program that was to be used for a Scrabble-type word game. The source can be found at this link under the name dawg.tar.gz.
BICOM – BIjective COMpressor Rate
BICOM is a freely available open source compressor. It uses a souped-up PPM algorithm, and is completely bijective.
Reader comment: Wow this is hot! …a bijective compressor using full size Rijndael encryption…
BIAC Rate
A bijective arithmetic compressor written in Java. Includes all source code, seems to be free.
BIRLE Rate
A bijective RLE compressor written in Java. Includes all source code, seems to be free.
Neural Network Text Compression Programs and Papers Rate
A couple of programs using neural networks for compression, along with a couple of papers by the author. This area of data compression is definitely underserved, check out what’s here and see if neural networks deserve more attention than they are getting.
Update: This page appears to now have some links to general lossless benchmarking info.
David A. Scott’s Fully Bijective Arithmetic Coder Rate
The term bijective as used by Scott means that for any given given file X you are guarantted that A( B( X ) ) == B( A( X ) ) == X, where A and B are a pair of bijectively matched programs. In this particular case, A and B are a compressor and decompressor that use arithmetic coding. Includes C++ source.
XML optimization Rate An article by Stephane Rodriguez on the CodeProject web site. Stephane describes his article as Revealing XML best practices with a utility tool and a framework. Yes, that means there is some sample code here as well.
Vcodex: A Discipline&Method Library for Transforming Data Rate Vcodex is a software collection for transforming data. Examples of data transformers include methods for compression/decompression, data differencing, encryption, etc. The source code distribution includes an implementation of Vcdiff using the framework.
Bit oriented input and output in Java Rate DevX published this nice piece describing bit oriented I/O in Java. This might not be directly related to Data Compression, but it is a requirement in nearly all data compression software. This site may require registration, I’m not sure.
The Open Compression Toolkit for C++ Rate The Open Compression Toolkit is a set of modular C++ classes and utilities for implementing and testing compression algorithms.
Simple interface and skeleton code for creating new compression algorithms.
Complete testing framework for validating and comparing new algorithms.
Support for algorithms that use external dictionaries/headers.
Utility classes and sample code for bitio, frequency counting, etc.
Boost CRC Library Rate The Boost project is designed to put very high-quality peer-revied libraries in the hands of you and me. CRC checking has nothing to do with compression per se, but it is frequently used when archiving to validate results.
Star Encoding in C++ Rate Star Encoding performs some preprocessing on text files, enabling standard compressors to do somewhat better on the files. This article explains the transform and provides some sample code.
A Generic, Reusable Diff Algorithm in C# – II Rate Another difference engine in C#.
Code to extract plain text from a PDF file Rate PDF documents are commonly used and their content is usually compressed. This article shows a simple C code that can be used to extract plain text from the PDF file.
Sequitir – inferring hierarchies from sequences Rate SEQUITUR is a method for inferring compositional hierarchies from strings. It detects repetition and factors it out of the string by forming rules in a grammar. The rules can be composed of non-terminals, giving rise to a hierarchy. It is useful for recognizing lexical structure in strings, and excels at very long sequences.
CRC Pointers Rate Somebody posting as thewhizkid complained to the comp.compression newsgroup that he just couldn’t figure out how to do a CRC calculation. He got a couple of good pointers here, including one to the zlib code, and another including a bit of Java that could do the job. I’ll add a pointer to my ancient-but-still-cogent article from DDJ, File Verification Using CRC to the mix. Between the three choices, I hope the poster was able to get a handle on the mysterious CRC.
PATRICIA trie implementation Rate This CodeProject article describes the development of a PATRICIA trie in the .NET framework. The actual code is written in C#, but naturally, it can be used with any of the .NET languages.
Spanish

Compression neural networks for feature extraction: Application to human recognition from ear images Rate This master’s thesis is available in PS format here. The abstract entry is in English, the Postscript document is in Spanish.
Standards

The VCDIFF Generic Differencing and Compression Data Format Rate A format that can be used to send the differences between documents with some efficiency. This is part of a proposed extension to the HTTP standard.
Tutorials, Reference, Presentations

Move to front The MTF algorithm is not very exciting, but it does a really nice job of compressing streams that have been put through the BWT transform. Arturo Campos gives an explanation of how to implement it in this paper.
One to One Compression This site discusses a characteristic of some compression algorithms that the author refers to as One to One compression. In a nutshell, this property means that for any file X, F( F'( X ) ) == X. (F is either the compressor or decompressor, and F’ is its opposite number.) This is definitely not the case for most conventional compression algorithms.
Optimizing putbits Most compression programs need to be able to do bit-oriented input and output. This is a problem, since most file systems are set up to do byte oriented I/O. Arturo Campos looks at ways to do an effective implementation of this neglected part of compression programming.
Huffman Coding with Priority Queues This article is really about using the priority queue containers that are part of the standard C++ library. The example program implements a Huffman Encoder using the queues, showing how they can do a fairly complex piece of work without too much coding on your part.
ACB, DMC, PPM, LZ – Classification, Idea, Comparision Rate
by George Buyanovsky. One of the only existing explanations of the mysterious ACB algorithm.
Shannon Fano Coding Rate
An overview of Shannon Fano coding from the folks at the DataCompression Reference Center. This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Aurora Borealis – a new way of compression Rate
This document describes the Aurora Borealis algorithm, which combines statistical analysis with a back end using an unknown type of coding. Author Michael Asse seems to have high hopes for this technique.
DataCompression.info reader Viktor F. had this to say: This compression method is inefficient. LZW can beat this easily. The author should read some books about compression.
Bob Cringely on Foveating Codecs Rate
Bob talks about new codes that use more bits to compress the stuff you’re looking at, and fewer bits for things on the sidelines.
Cyclic Redundancy Check Rate
The definition from the NIST Dictionary of Algorithms and Data Structures.
comp.dcom.fax FAX FAQ Rate This article contains the answers to some Frequently Asked Questions (FAQ) often seen in the USENET newsgroup comp.dcom.fax relating to facsimile standards, software, and hardware. Most importantly, contains an explanation of FAX encoding.
XML optimization Rate An article by Stephane Rodriguez on the CodeProject web site. Stephane describes his article as Revealing XML best practices with a utility tool and a framework. Yes, that means there is some sample code here as well.
3DCompression.com Rate A directory of links and resources on compressing the 3D models used for computer graphics and other large geometric datasets. This is a replacement for the site at http://www.cc.gatech.edu/~kingd/3Dcompression.html.
Build your own one-on-one compressor Rate The author gives a description of a proposed bijective compression scheme.
Star Encoding in C++ Rate Star Encoding performs some preprocessing on text files, enabling standard compressors to do somewhat better on the files. This article explains the transform and provides some sample code.
A Generic, Reusable Diff Algorithm in C# – II Rate Another difference engine in C#.
Code to extract plain text from a PDF file Rate PDF documents are commonly used and their content is usually compressed. This article shows a simple C code that can be used to extract plain text from the PDF file.
What is D-Gap Compression? Rate BitMagic is a C++ library that deals with dynamic bit vectors. It supports a couple of different ways to compress these bit vectors. This page discusses D-Gap Compression.
Bitmagic Hierarchical Compression Rate BitMagic is a C++ library that deals with dynamic bit vectors. It supports a couple of different ways to compress these bit vectors. This page explains how to perform common operations on bit vectors while they are compressed in memory.
PATRICIA trie implementation Rate This CodeProject article describes the development of a PATRICIA trie in the .NET framework. The actual code is written in C#, but naturally, it can be used with any of the .NET languages.
Spoofing the Wily CRC Rate This article on The Code Project web site shows you how to calculate a CRC, but even better it shows you how to create a file that will have a given CRC value.
Letter frequency in normal English text Rate No documentation or hint of how this page was created, but it purports to give you some stats on the frequency of characters in English text.
File Compression: New Tool for Life Detection? Rate Researchers looking for signs of life have decided that complexity might be a good indicator. What better to measure complexity than gzip?
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Files

The Files label used here doesn’t refer to source files, but rather benchmark, test, and reference files.
Audio

MPEG Audio Resources and Software Rate
Links to lots of info regarding the audio compression portions of the MPEG standards. This includes an overview, the MPEG Audio FAQ, pointers to resources, some free software, and test bitstreams.
SQAM – Sound Quality Assessment Material Rate This site apparently holds a set of files that were used to evaluate MPEG audio compression algorithms.
Compression Technology in Multimedia Rate Lots of information on this site concerning compression of still pictures, moving pictures, and audio. Much of the site is devoted to comparisons of a few different algorithms. A report section draws a few conclusions about the whole thing.
Compression Codecs Rate This site has a nice collection of codecs, including DirectShow filters, MPG4, MJPEG, and other video codecs. A few audio codecs and AVI test sequences as well.
Benchmarks

CCITT standard fax images Rate
TIFF versions of the CCITT images.
PNG Suite from Willem van Schaik Rate
This is Willem van Schaik’s suite of PNG icons for testing PNG decoder engines, PNG viewers, and PNG browsers.
Waterloo BragZone Rate
Comparing different image compression programs has always been difficult. As a suite of test images and a place for archiving results, the Waterloo BragZone hopes to overcome these problems. Central to the effort is the Waterloo Repertoire, a suite of 32 test images
Waterloo BragZone test suite Rate
In the BragZone you will find the following:
A suite of test images, the “Waterloo Repertoire”.
Rate-Distortion plots for various compression codecs.
The data from which the above plots are derived.
Sample images at selected compression ratios.
Project Runeberg Rate
A huge collection of Swedish language text files
The British National Corpus Rate The British National Corpus (BNC) is a 100 million word collection of samples of written and spoken language from a wide range of sources, designed to represent a wide cross-section of current British English, both spoken and written.
The Canterbury Corpus Rate This is the home page for the Canterbury Corpus, a test suite designed to provide a standard set of files for lossless compressoion testing. You will find links to the actual files in the test suite, as well as papers and test results.
Silesia compression corpus Rate Sebastian Deorowicz decided to create a compression corpus of his own, attempting to overcome some of the deficiencies he sees in the old guard.
Benchmark Images and Files Rate David Cary is a major link farmer. One of the sections of his massive Data Compression page has links to various images and files that are used in various benchmarks.
Data Compression

Data Compression Corpora Jürgen Abel has a great Data Compression site, and keeps a set of pointers to standard sets of files used for compression. He recently added a reference to the Protein Corpus, a set of difficult to compress files that were first published at the 1999 Data Compression Conference.
Matsusaka University Anonymous FTP Server Rate
An ftp site for compression software. This includes mirrors of some hard to find sites, such as those of D.J. Wheeler. Needs organization, and I often find it a bit slow from the US.
The New Canterbury Corpus Rate No details, but it appears to be a collection of files designed to represent a slightly wider range of modern applications.
Data Compression Benchmark Suite Rate A set of links to files that are used to benchmark various data compression algorithms.
Image Compression

The USC-SIPI Image Database Rate
The USC-SIPI image database is a collection of digitized images. It is maintained primarily to support research in image processing, image analysis, and machine vision. Contains copies of the mystical goddess Lenna.
CCITT standard fax images Rate
TIFF versions of the CCITT images.
Waterloo BragZone test suite Rate
In the BragZone you will find the following:
A suite of test images, the “Waterloo Repertoire”.
Rate-Distortion plots for various compression codecs.
The data from which the above plots are derived.
Sample images at selected compression ratios.
Image set used in ACT Rate
A SET of 23 images totalling 27,133,146 bytes. The file type is RAS, does that mean that the files are a simple raster dump? I’m not sure. These files are listed in a few different places as being used in benchmarks.
CCITT standard images (Bilevel) Rate Images commonly used in compression tests are stored here in Sun raster format. At this time I believe that all you will find here are gray scale images.
Compression Technology in Multimedia Rate Lots of information on this site concerning compression of still pictures, moving pictures, and audio. Much of the site is devoted to comparisons of a few different algorithms. A report section draws a few conclusions about the whole thing.
Google – Compression Test Images Rate Google’s directory entry point for test images used in data compression.
Standard Test Images and Sequences Rate This site has links to a few standard test images and sequences, including 512×512 8 bit images, and a good selection of QCIF sequences.
Computer Vision Test Images Rate A list of links to test images. Utopia for the benchmark junkie.
Image & Video Quality Assessment at LIVE Rate The folks at LIVE conducted a subjective test of images at various compression levels, and have made the results available here. The images and results are both available here.
JPEG-2000

JPEG 2000 Code and Test Data Rate This page contains links to sample code and test data for implementing the JPEG 2000 standard. Looking for conformance files? This is the place. Looking for working implementations? You can find several here.
JPEG 2000 Part 4 Conformance Test Files Rate Part 4 of the standard relates to conformance. The files on this site are used in conformance testing. This web site implies that this part of the standard will soon be available for free, but as of March, 2003, this is not the case.
Lossless Compression

CCITT standard fax images Rate
TIFF versions of the CCITT images.
LZO

LZO download site Rate The primary site for downloading LZO files. This includes mini-LZO, a shrunk down version of the LZO library, Perl-LZO, and Python-LZO.
MP3/MPEG Audio

MPEG Audio Resources and Software Rate
Links to lots of info regarding the audio compression portions of the MPEG standards. This includes an overview, the MPEG Audio FAQ, pointers to resources, some free software, and test bitstreams.
MPEG

MPEG Audio Resources and Software Rate
Links to lots of info regarding the audio compression portions of the MPEG standards. This includes an overview, the MPEG Audio FAQ, pointers to resources, some free software, and test bitstreams.
Compression Technology in Multimedia Rate Lots of information on this site concerning compression of still pictures, moving pictures, and audio. Much of the site is devoted to comparisons of a few different algorithms. A report section draws a few conclusions about the whole thing.
Compression Codecs Rate This site has a nice collection of codecs, including DirectShow filters, MPG4, MJPEG, and other video codecs. A few audio codecs and AVI test sequences as well.
PNG

PNG Suite from Willem van Schaik Rate
This is Willem van Schaik’s suite of PNG icons for testing PNG decoder engines, PNG viewers, and PNG browsers.
Speech

HawkVoice Speech Samples Rate Some speech samples that have been encoded at various rates using various codecs. If you’ve never heard speech encoded at 1.4 Kbps, here’s a chance to check it out.
Video

The TML Project WEB-Page and Archive Rate I believe this page contains test sequences and software for the Video Quality Experts group. It appears that the software and sequences are available for the public.
H.261 Video Coding Rate Peter Cherriman’s page on H.261 coding, includes information, pointers, and a couple of demo sequences.
H.263 Video Coding Rate Peter Cherriman’s page on H.263 coding, includes information, pointers, and a couple of demo sequences.
Original Video Sequences Rate A set of test sequences in QCIF format plus additional H.263 sequences. Used by the Video Coding Experts group, which seems to be part of an ITU group.
Standard Test Images and Sequences Rate This site has links to a few standard test images and sequences, including 512×512 8 bit images, and a good selection of QCIF sequences.
VCEG ftp server Rate This is described as the ftp server for the Video Coding Experts Group, which is working on H.26L and other video projects. A ton of stuff here, no guideposts or indices, have at it.
Compression Codecs Rate This site has a nice collection of codecs, including DirectShow filters, MPG4, MJPEG, and other video codecs. A few audio codecs and AVI test sequences as well.
Multimedia Test Sequences Rate Welcome to media.xiph.org, a repository for freely-redistributable test sets. We use these to test our codecs, and hope you will too. This site includes a partial mirror of the Video Quality Experts Group test sequences as well.
Image & Video Quality Assessment at LIVE Rate The folks at LIVE conducted a subjective test of images at various compression levels, and have made the results available here. The images and results are both available here.
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Finnish

Finland, like New Zealand, seems to produce a disproportionately large number of people interested in data compression. Sometimes they produce information in their native language. Here are pointers to a few examples.
Archiving

SBC Archiver Rate
The submitter said: SBC is Burrows Wheeler Transform based file archiver. It’s one of the fastest BWT implementations with high compression ratio. SBC also introduces a high security options with a number of strong encryption algorithms.
SBC appears to be shareware. Comment from a DCL user: Cool archiver; the author has made great effors to make it really fast and also added a lot of heuristics to behave well on multimedia data.
Burrows-Wheeler Transform/Block Sorting

SBC Archiver Rate
The submitter said: SBC is Burrows Wheeler Transform based file archiver. It’s one of the fastest BWT implementations with high compression ratio. SBC also introduces a high security options with a number of strong encryption algorithms.
SBC appears to be shareware. Comment from a DCL user: Cool archiver; the author has made great effors to make it really fast and also added a lot of heuristics to behave well on multimedia data.
Image Compression

Yleisimpiä kuvanpakkausmenetelmiä ja niiden vertailua Rate
This appears to be an overview of various data compression methods applied to image compression, both lossy and lossless. The page is entirely in what appears to be Finnish.
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Fractals

Fractal image compression is a lossy compression technique. Compression is performed by locating self-similar sections of an image, then using a fractal algorithm to generate the sections.
Fractals are a very interesting field of study, but this page won’t attempt to cover everything there is to know about fractals. For the most part, we will only look at fractals as they relate to compression. To learn more about this fascinating subject, try looking into some of the resources pointed to by the Fractal FAQ

[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Books

Fractals Everywhere Rate
by Michael F. Barnsley. A revised and updated textbook focusing on how fractal geometry can be used to model real objects in the physical world. DCL reader TJ says This is, in my experience, the best mathematics book I have ever seen
If you are interested in buying this book, please use the link on this page. Your purchase will help to support this site.
Fractal Image Compression : Theory and Application Rate
by Yuval Fisher (Editor). Featuring a collection of articles by twelve experts in the field of fractal image compression, this book contains the complete details of how to encode and decode images, offering working codes that are usable in applications. Includes some of the latest results in this field..
If you are interested in buying this book, please use the link on this page. Your purchase will help to support this site.
Fractal Imaging, by Ning Lu Rate
ISBN: 0124580106, April 1997, US Price: $55.95. The publisher says: Fractal Imaging presents the logic, technology, and various uses of fractal imaging by analyzing a complete, usable fractal image representation system. The book appears to be designed to help apply fractal imaging.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Fractal Image Compression Rate
by Michael F. Barnsley, Lyman P. Hurd, Louisa F. Anson (Illustrator). A sequel to Barnsley’s first book.
If you are interested in buying this book, please use the link on this page. Your purchase will help to support this site.
Commercial Programs

Altamira Group Rate
These guys apparently make a couple of variations on a product called Genuine Fractals. The product is a Photoshop plugin that appears to read fractal file formats and do some sort of scaling. If this is a grotesque misrepresentation of what the product does, feel free to email a correction.
Companies/Organizations

Waterloo Fractal Compression Project Rate
The Waterloo Fractal Compression Project is part of a general research programme dedicated to the study of fractal analysis and Iterated Function Systems/Fractal Transforms from both theoretical as well as practical perspectives.
Signal and Image Processing Group Rate The University of Bath has a group that is advertised as “world leaders in still image and video coding.” They appear to be interested in lossy compression based on DCT, Wavelets, and Fractal compression. This is their home page.
French

Compression des images (et autres documents) Rate
This site has pointers to various sits related to image compression. The entire site is written in French.
Fractal Image Compression Rate Online demos of Fractal compression and decompression. Available in English, French, and German.
German

Fractal Image Compression Rate Online demos of Fractal compression and decompression. Available in English, French, and German.
Links

Yuval Fisher’s Fractal Links Rate
A very comprehensive page of links from Yuval Fisher, who is right there in the middle of the whole fractal business. This page features a glut of links to papers, bibliographies, books, conferences, and software. You can’t go wrong here.
Waterloo Fractal Compression Project Rate
The Waterloo Fractal Compression Project is part of a general research programme dedicated to the study of fractal analysis and Iterated Function Systems/Fractal Transforms from both theoretical as well as practical perspectives.
Waterloo Fractal Compression Project Rate
The Waterloo Fractal Compression Project is part of a general research programme dedicated to the study of fractal analysis and Iterated Function Systems/Fractal Transforms from both theoretical as well as practical perspectives
Vladimir Valenta’s Home Page Rate
Vladimir has pointers to a batch of his papers here, which seem to concentrate on image compression, including VQ and Wavelet based compression. Plus many links to image compression, fractal, and wavelet pages.
Compression des images (et autres documents) Rate
This site has pointers to various sits related to image compression. The entire site is written in French.
Spanky Fractal Database Rate A database of Fractal resources.
Fractal Image Compression Bibliography Rate This bibliography was compiled from a number of sources, including the extensive bibliographies (in postscript form) by John Kominek and by Dietmar Saupe and Raouf Hamzaoui.
Signal and Image Processing Group Rate The University of Bath has a group that is advertised as “world leaders in still image and video coding.” They appear to be interested in lossy compression based on DCT, Wavelets, and Fractal compression. This is their home page.
Fractal Compression Rate A giant bibliography with pointer to on-line papers, as well as some basic information on the state of the art. Not for the timid or the beginner.
Newsgroup Posts

Introduction to Fractal compression Rate
The comp.compression FAQ provides you with this introduction.
What is the state of fractal compression? Rate
The comp.compression FAQ addresses this somewhat controversial question.
Non-Commercial Programs

IFS – Fractal Image Compression Rate
This page offers a program called the IFS Application Framework, a freeware program that does fractal image coding, along with some docs. The author of the page puts it this way: We use insanely complicated mathematics to achieve big compression ratios.
Papers/Documentation

Waterloo Fractal Compression Project Rate
The Waterloo Fractal Compression Project is part of a general research programme dedicated to the study of fractal analysis and Iterated Function Systems/Fractal Transforms from both theoretical as well as practical perspectives
Fractal Compression Papers Archive Rate
We keep a store of papers originating from
Waterloo
Montreal
External sources.
All papers are in postscript format and are gzipped to save space. The filenames correspond to the naming convention established in my extensive Fractal Bibliography. It probably makes most sense to examine the bibliography first (it is updated regularly), before going on a paper downloading spree.
Fractal Image Compression for Spaceborne Transputers Rate
A dissertation by Keith Howell which evaluates the suitability of Fractal Compression for spacecraft images. Keith says he is willing to supply source code upon request.
Vladimir Valenta’s Home Page Rate
Vladimir has pointers to a batch of his papers here, which seem to concentrate on image compression, including VQ and Wavelet based compression. Plus many links to image compression, fractal, and wavelet pages.
Fractal image compression based on delaunay triangulation Rate
PhD thesis by Franck Davoine, 20 December 1995. The key to a good fractal compression algorithm is the method by which it breaks down segments of an image into smaller pieces, called partitioning. Davoine introduces a partitioning method based on Delaunay triangulation.
Application of the BSP Model in Fractal Image Compression Rate An MS dissertation, with the complete text online.
Genetic Algorithms for Fractal Image and Image Sequence Compression Rate In this paper we present a method that uses Genetic Algorithms (GAs) to find a Local Iterated Function System (LIFS) that encodes a single image. By doing this, the time needed to achieve this LIFS is reduced by about compared with Barnsley’s method if similar image quality is desired. If less quality is acceptable, using a GA we can vary the time the encoding will take by changing parameters such as population size and number of generations allowed.
Recent Publications of Lai-Man PO Rate Many publications spanning a wide variety of image processing topics. Dr. Po has papers here on both wavelet and fractical compression, motion estimation, etc.
The Leipzig Paper Collection on Fractal Image Compression Rate A giant bibliography on Fractal Image Compression. Links to online versions of some, but far from all, papers.
Top Ten Reasons why Fractal Image Compression is not Fractal Rate A not very serious trashing of fractal compression.
Fractal Compression Rate A giant bibliography with pointer to on-line papers, as well as some basic information on the state of the art. Not for the timid or the beginner.
Algorithm for Fast Fractal Image Compression Rate Fractal image compression is a promising new technology that may successfully provide a codec for PC-to-PC video communications. Unfortunately, the large amount of computation needed for the compression stage is a major obstacle that needs to be overcome. This paper introduces the Fast Fractal Image Compression algorithm, a new approach to breaking the “speed problem” that has plagued previous efforts.
A Non Uniform Segmentation Optimal Hybrid Fractal/dct Image Compression Algorithm Rate by Gerry Melnikov, Aggelos K. Katsaggelos. In this paper a hybrid fractal and Discrete Cosine Transform (DCT) coder is developed.
Geoff Davis Rate Geoff Davis’s home page. Geoff has published several of his wavelet papers on the web, including an interesting analysys of Fractal compression in terms of wavelets. At one time Geoff Davis was responsible for a Wavelet toolkit, but it isn’t on his new site. Please forward pointers is you find it.
Patents/Licenses

US Patent 5347600: Method and apparatus for compression and decompression of digital image data Rate A fractal compression patent held by Iterated Systems, Inc. This appears to be a very fundamental patent issued 13 September 1994.
US Patent 4941193: Methods and apparatus for image compression by iterated function system Rate One of the earliest patents regarding fractal compression. Issued 10 July 1990, assigned to Iterated Systems.
US Patent 5065447: Method and apparatus for processing digital data Rate A fundamental patent for fractal image compression assigned to Iterated Systems. This patent was issued 12 November 1991.
Source Code

Fractal Image Compression for Spaceborne Transputers Rate
A dissertation by Keith Howell which evaluates the suitability of Fractal Compression for spacecraft images. Keith says he is willing to supply source code upon request.
Tutorials, Reference, Presentations

Fractal Image Compression Rate
An entry from some sort of online encyclopedia giving a quick overview of Fractal Compression.
Fractal Frequently Asked Questions and Answers Rate
The Usenet newsgroup sci.fractals and the listserv forum frac-l are devoted to discussions on fractals. This FAQ (Frequently Asked Questions) is an electronic serial compiled from questions and answers contributed by many participants in those discussions. This FAQ also lists various archives of programs, images, and papers that can be accessed through the global computer networks (WWW/Internet/BITNET) by using email, anonymous ftp, gophers, and World Wide Web browsers. This FAQ is not intended as a general introduction to fractals, or a set of rigorous definitions, but rather a useful summary of ideas, sources, and references.
DCL user feedback: The links on that particular page are extremely outdated, as well as a lot of the information. It’s still useful, but there’s gotta be a more up-to-date alternative

Fractals and Scale Rate By David G. Green, Environmental and Information Sciences, Charles Sturt University. A short tutorial that provides an introduction to just what fractals are all about.
Iterated function systems and compression Rate An entry from a web page entitled “Fractal Questions and Answers”.
Fractal Compression Rate Stefan Adolf’s page discussing some experimentation he’s doing with Fractal compression. A cry for help?
Wikipedia entry: Fractal Compression Rate This Wikipedia entry describes Fractal image compression. Short overview.
Fractal Image Compression Rate Online demos of Fractal compression and decompression. Available in English, French, and German.
Advanced Fractals Rate A Web-based tutorial on Fractals, which includes a description of fractal image compression.
On Fractal Compression Rate An overview of Fractal Compression.
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French

This page contains links to compression resources documented or written in French.
Archiving

ZipWave Rate
A shareware visual archiving program that advertises that it supports 15 popular archive formats. Note the link to the French version of the program and web page.
ZipGenie Rate
ZipGenie is yet another archiver that supports a scad of formats, including zip, cab, arj, lha, lza, arc, gz, tar, zoo, gzip, rar, tgz, ace, jar, pak, and z. The author says that the download is multilingual, with help in German, English, Spanish, and French.
Compact Pro Rate Compact Pro is a shareware file compression and archival utility for the Mac. It compresses and stores files in “archives” which may span multiple diskettes. Compact Pro supports data encryption (US and Canadian users only) and self-extracting archives.
ArjFolder Rate ArjFolder is a utility that makes it easy to read or write ARJ and ZIP files, and to read a slew of other file types. Sit can be viewed in French or English.
Rarissimo Rate Rarissimo is a file utility to automatically compress and/or uncompress files, companion for the award winning compression program WinRAR. Distinguishable from other compression solutions by its ability to fully preserve NTFS alternate streams. This feature provides automatic compression/uncompression for Macintosh files stored on NT volumes preserving their filenames and peculiar structures – it means for example that you can use Rarissimo to send and receive Macintosh files using any standard FTP process (and not only Mac-based programs).
DataCompression.info user Marie M. said: This utility is very specialized so not easy to find. It is a great help to transfer Mac files without a special Mac ftp utility.
Audio

BonkEnc Rate BonkEnc is an audio CD ripper and an encoder for various audio formats. It can produce Ogg Vorbis, MP3 and BONK files. More formats are available through plug-ins.
MediaInfo Rate Supplies you with detailed info about the attributes of all sorts of media files, naturally including MP3, AVI, WAV, MPEG2, and much, much more. Looks to be Win32 only.
Coding

Contributions à la compression de données Rate Steven Pigeon’s Ph. D Thesis from the University of Montreal. Proposes a new set of universal codes, which he dubs taboo codes, as well as new optimization algorithms for (Start, Step, Stop) codes. Plus lossy variations on LZW.
Data Compression

Compression des images (et autres documents) Rate
This site has pointers to various sits related to image compression. The entire site is written in French.
Esoterica/Miscellany

Rarissimo Rate Rarissimo is a file utility to automatically compress and/or uncompress files, companion for the award winning compression program WinRAR. Distinguishable from other compression solutions by its ability to fully preserve NTFS alternate streams. This feature provides automatic compression/uncompression for Macintosh files stored on NT volumes preserving their filenames and peculiar structures – it means for example that you can use Rarissimo to send and receive Macintosh files using any standard FTP process (and not only Mac-based programs).
DataCompression.info user Marie M. said: This utility is very specialized so not easy to find. It is a great help to transfer Mac files without a special Mac ftp utility.
Fractals

Compression des images (et autres documents) Rate
This site has pointers to various sits related to image compression. The entire site is written in French.
Fractal Image Compression Rate Online demos of Fractal compression and decompression. Available in English, French, and German.
Image Compression

Compression des images (et autres documents) Rate
This site has pointers to various sits related to image compression. The entire site is written in French.
JPEG

Morgan Multimedia. Rate
This company makes a M-JPEG codec and would like to sell it to you. Much of the page is written in French.
Digital Photography from Agfa Rate A complete short course on digital photography from Agfa. It shows up here because Lesson 6 is on The Right Compression. You get a discussion of various formats, including GIF, JPEG, JPEG2K, and PNG. Best of all, it looks like the entire page is available in English, German, Spanish, and Portuguese.
JPEG-2000

Digital Photography from Agfa Rate A complete short course on digital photography from Agfa. It shows up here because Lesson 6 is on The Right Compression. You get a discussion of various formats, including GIF, JPEG, JPEG2K, and PNG. Best of all, it looks like the entire page is available in English, German, Spanish, and Portuguese.
LZ78/LZW and derivatives

Contributions à la compression de données Rate Steven Pigeon’s Ph. D Thesis from the University of Montreal. Proposes a new set of universal codes, which he dubs taboo codes, as well as new optimization algorithms for (Start, Step, Stop) codes. Plus lossy variations on LZW.
MP3/MPEG Audio

BonkEnc Rate BonkEnc is an audio CD ripper and an encoder for various audio formats. It can produce Ogg Vorbis, MP3 and BONK files. More formats are available through plug-ins.
DropMP3 Rate The author of this program, Philippe Laval, says You are looking for an application to encode your sound files in MP3, DropMP3 is done for you.. The program runs on MacOS, uses the LAME encoder, and is released under the GPL. Note that the web page is more or less duplicated in English and French.
Version 1.0.6 is shipping as of March, 2003.
MPEG

Flask MPEG Rate
The home site for the Flask MPEG conversion program. A program that can convert back and forth between MPEG-1 and MPEG-2. Change parameters such as frame rate, etc. Free!
PNG

Digital Photography from Agfa Rate A complete short course on digital photography from Agfa. It shows up here because Lesson 6 is on The Right Compression. You get a discussion of various formats, including GIF, JPEG, JPEG2K, and PNG. Best of all, it looks like the entire page is available in English, German, Spanish, and Portuguese.
Video

Avi-Ogm Info Rate This Win32 app probes your AVI files and returns a nicely formatted GUI telling you all sorts of interesting things such as sample rate, codec used, framerate. Oh, and it seems to be written for the French speaker.
MediaInfo Rate Supplies you with detailed info about the attributes of all sorts of media files, naturally including MP3, AVI, WAV, MPEG2, and much, much more. Looks to be Win32 only.
Wavelets

Ondolette.com Rate
A forum dedicated to the discussion of Wavelets. This link takes you to the French language version of the board – click on the “English” link on the left side of the page for English language discussion.
Zip

Jean-loup Gailly Rate
His home page, with English and French language versions.
PentaZip Rate
PentaZip has a very nice feature set, supports advanced encryption, large archives, Windows shell integration, and all the other good stuff you’ve come to expect. Also supports a wide variety of languages.
Release 6.0.1.190 shipped in November, 2003
EzZip Suitcase Rate
This product bills itself as the “Ultimate Multilingual User Friendly” compression tool. The usual Zip features plus support for six different languages. Fifteen day free trial download.
Reader Donald J. says Excellent zip utility and definitely the easiest I have ever used.
Filzip Rate
Yet another free Zip program with the usual cast of features. Supports a pretty good variety of archives, runs under Win32 only, etc.
Filzip 3.0.1 is shipping in May, 2004.
ZipCentral Rate
ZipCentral is a free and easy to use zip file manager with all the utilities you need to manage your zip files. The goal of ZipCentral is to be the most robust freeware zip-package you can find today. It is a great tool for the beginner as well as the expert. Working with zip files has never been easier!
PifPaf zip/unzip Rate PifPaf zip/unzip is a small and simple drag-and-drop ZIP compressor for MacOS and MacOS X.. PifPaf Mac/Win is a small and simple drag and drop LZW compressor (DiskDoubler type, file’s tree keeping) for MacOS AND Windows (.ssr extension) This is a French language site.
zlib

Jean-loup Gailly Rate
His home page, with English and French language versions.
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German

Various topics in German language
Archiving

ZipGenie Rate
ZipGenie is yet another archiver that supports a scad of formats, including zip, cab, arj, lha, lza, arc, gz, tar, zoo, gzip, rar, tgz, ace, jar, pak, and z. The author says that the download is multilingual, with help in German, English, Spanish, and French.
PowerArchiver Rate
Yet another Windows archiving program. PowerArchiver comes with a nice long list of supported formats: ZIP, CAB, LHA (LZH), TAR, TAR.GZ, TAR.BZ2, BH, RAR, ARJ, ARC, ACE, ZOO, GZ, BZIP2, XXE, and UUE. Plus a built-in viewer for JPG, GIF, and a few other formats.
Release 9.0 of PowerArchiver shipped July, 2004.
AMG Version 2.3 Rate
The docs say it all: der ultimative FREEWARE-Packer. Yes, the internal documentation for this archiver is in German, but users limited to English should still be able to figure this program out.
Compact Pro Rate Compact Pro is a shareware file compression and archival utility for the Mac. It compresses and stores files in “archives” which may span multiple diskettes. Compact Pro supports data encryption (US and Canadian users only) and self-extracting archives.
Zipbit Rate Zipbit is yet another inexpensive Win32 archiver with support for a wide range of archive types. Creates SFX files, integrates with Windows Explorer, and has localized versions for English, German, and Russian.
Version 1.05 is shipping as of April, 2003.
Arithmetic Coding

Arithmetic Coding revealed – A guided tour from theory to praxis Rate
An updated and translated version of our German paper “Proseminar Datenkompression – Arithmetische Kodierung” from 2001. To the best of our knowledge, it is the first comprehensive paper that describes the whole way from the basic principles of AC up to a simple implementation, fully documented with C++ source code.
Proseminar Datenkompression – Arithmetische Kodierung Rate
This page gives an introduction to Arithmetic Coding and shows how to implement it using floats or integers. There is also a proof of the efficiency of the algorithms, along with visualization and Win32 binaries. This page is in English and includes links to material in both German and English.
DataCompression.info user Juergen Abel found the site quite good: Clear description, especially the explanation of the renormalisation part, full source code.
Audio

BonkEnc Rate BonkEnc is an audio CD ripper and an encoder for various audio formats. It can produce Ogg Vorbis, MP3 and BONK files. More formats are available through plug-ins.
GermaniXEncoder Rate GermaniXEncoder is a universal Transcoder for various sound formats like MP3, MP2, Real Audio, WMA, Ogg Vorbis, ALF2CD, DSP, GSM, G.721, G.723, G.726, RAW, PCM, ADPCM, uLaw, aLaw, MPC, and Monkeys Audio. In addition, the Encoder has a transformer for some transforming features, an Audio Recorder for recording from all input sources to mp3, mp2, pcm, adpcm, wma and ogg-vorbis. You can also split large MP3 files with their CUE sheets into songs.
Version 1.80.1195 RC2 was shipping as of Februaru, 2002.
Burrows-Wheeler Transform/Block Sorting

Grundlagen des Burrows-Wheeler-Kompressionsalgorithmus This is another German preprint of Jürgen Abel describing the principles of the Burrows-Wheeler Compression Algorithm. An implementation of a BWT based compressor with a compression rate of 2.25 bps on the Calgary Corpus is presented. The paper will be published in the German journal “Informatik – Forschung und Entwicklung”, Springer-Verlag Heidelberg, Association for Informatics (Gesellschaft für Informatik eV.)
Verlustlose Datenkompression auf Grundlage der Burrows-Wheeler-Transformation This is a preprint of a paper by Jürgen Abel describing the functionality of a basic but quite fast Burrows-Wheeler compressor. Jürgen reports that this will be published in PIK, a German-language journal on Communications and Information Theory.
Data Compression

Kompressionsalgorithmen Rate
A big survey paper of data compression techniques by Joachim Schwarz und Guido Sörmann. German language.
AG Information und Komplexität Rate A nice set of links to various resources related to info theory and data compression. German language.
Fractals

Fractal Image Compression Rate Online demos of Fractal compression and decompression. Available in English, French, and German.
Image Compression

Bilddatenkompression/Image Data Compression Rate
Subtitled Basics, Standards and Wavelet-Based Algorithms for Image and Video Coding. This German-language textbook contains full source code (ANSI-C) of a wavelet-based image coder.
Information Theory

AG Information und Komplexität Rate A nice set of links to various resources related to info theory and data compression. German language.
Internet

Zipserver Rate Zipserver is a little HTTP server that serves up static documents from inside Zip files. Great way to put manuals or archived documents on line, don’t you think?
JPEG

Bilddatenkompression/Image Data Compression Rate
Subtitled Basics, Standards and Wavelet-Based Algorithms for Image and Video Coding. This German-language textbook contains full source code (ANSI-C) of a wavelet-based image coder.
Digital Photography from Agfa Rate A complete short course on digital photography from Agfa. It shows up here because Lesson 6 is on The Right Compression. You get a discussion of various formats, including GIF, JPEG, JPEG2K, and PNG. Best of all, it looks like the entire page is available in English, German, Spanish, and Portuguese.
JPEG-2000

JPEG 2000 Dropper Rate
A free Max OS X program that converts your images to JPEG 2000.
Luratech Rate
Luratech has plugins and an SDK for both their proprietary format and JPEG2000. Products come in a dizzying array of options, ActiveX controls, C-SDK, Java-SDK, plugins for PhotoShop or browsers. Note that some of their products can now be downloaded as freeward!
Note: What was once LuraTech is now Algo Vision LuraTech.
Reader Tom H. says: Luratech is the fastest licensable SDK out there right now
Digital Photography from Agfa Rate A complete short course on digital photography from Agfa. It shows up here because Lesson 6 is on The Right Compression. You get a discussion of various formats, including GIF, JPEG, JPEG2K, and PNG. Best of all, it looks like the entire page is available in English, German, Spanish, and Portuguese.
Lossless Compression

X-PRESS Rate
A Multiplatform data compression program, looks like it runs on a wide variety of IBM mini and mainframes. Company has a dual-language web site, with English and German language versions.
Reversible Kompressionsalgorithmen Rate
What appears to be a discussion of Lossless compression algorithms, including Huffman coding, Arithmetic Coding, LZW, LZSS, and LZH.
GEMAC Rate This company sells an IP core that performs lossless data compression. Not sure what algorithm they are using, it is described as “GEMAC’s data compression algorithm.” This algorithm was first published at DCC ’95, and is described as a hybrid of ZL1 and ZL2, created with the goal of maximizing compression rate.
limes datentechnik® gmbh Rate These folks deliver a tool called FLAM which uses a patented data compression algorithm to do something. The site has English and German language versions, but doesn’t seem to have any detailed information on FLAM.
Lossy Compression

Irreversible Kompressionsalgorithmen Rate A study of lossy compression algorithms, including discussion of JPEG, MPEG, and the DCT.
LZ77/LZSS and derivatives

LZ77 Daten – Dekompression auf dem 68HC11 Micro Controller Rate Christian Scheurer wrote up his LZ77 project that was targeted to the 68HC11 processor. It’s written in German, perhaps you could use Babel-fish to translate. Source code included.
MP3/MPEG Audio

BonkEnc Rate BonkEnc is an audio CD ripper and an encoder for various audio formats. It can produce Ogg Vorbis, MP3 and BONK files. More formats are available through plug-ins.
MPEG

Flask MPEG Rate
The home site for the Flask MPEG conversion program. A program that can convert back and forth between MPEG-1 and MPEG-2. Change parameters such as frame rate, etc. Free!
Bilddatenkompression/Image Data Compression Rate
Subtitled Basics, Standards and Wavelet-Based Algorithms for Image and Video Coding. This German-language textbook contains full source code (ANSI-C) of a wavelet-based image coder.
PNG

Digital Photography from Agfa Rate A complete short course on digital photography from Agfa. It shows up here because Lesson 6 is on The Right Compression. You get a discussion of various formats, including GIF, JPEG, JPEG2K, and PNG. Best of all, it looks like the entire page is available in English, German, Spanish, and Portuguese.
Self Extractors/Executable Packers

Zipbit Rate Zipbit is yet another inexpensive Win32 archiver with support for a wide range of archive types. Creates SFX files, integrates with Windows Explorer, and has localized versions for English, German, and Russian.
Version 1.05 is shipping as of April, 2003.
Video

Inhalt Rate This page gives short descriptions of MPEG and H.261 in German. Different systems of coding color information are described as well. Brief, but useful if you don’t want to get bogged down in details.
Wavelets

Luratech Rate
Luratech has plugins and an SDK for both their proprietary format and JPEG2000. Products come in a dizzying array of options, ActiveX controls, C-SDK, Java-SDK, plugins for PhotoShop or browsers. Note that some of their products can now be downloaded as freeward!
Note: What was once LuraTech is now Algo Vision LuraTech.
Reader Tom H. says: Luratech is the fastest licensable SDK out there right now
MT-WICE® – Wavelet based image compression Rate
A proprietary image compression system using wavelets by MeVis Technology. Browser plug-ins available, naturally. Links to German language version of the page.
A DCL reader had this to say: Achieves high compression and has a useful interface. I have used only the non-registered version 2.6e very powerful and probably superior to JWizard by Pegasus.
Bilddatenkompression/Image Data Compression Rate
Subtitled Basics, Standards and Wavelet-Based Algorithms for Image and Video Coding. This German-language textbook contains full source code (ANSI-C) of a wavelet-based image coder.
Lurawave SmartCompress Rate This is a freeware image compressor that does wavelet based compression. Lurawave appears to have all their products and documentation available in German language as well as English. In order to establish their products they are making much of it available as freeware.
Publications of Tilo Strutz Rate Links to the papers of Tilo Strutz, concentrating on wavelet based compression. Some papers published in German. Note that Tilo Strutz has added a textbook on image compression to his list of publications.
Zip

Filzip Rate
Yet another free Zip program with the usual cast of features. Supports a pretty good variety of archives, runs under Win32 only, etc.
Filzip 3.0.1 is shipping in May, 2004.
PentaZip Rate
PentaZip has a very nice feature set, supports advanced encryption, large archives, Windows shell integration, and all the other good stuff you’ve come to expect. Also supports a wide variety of languages.
Release 6.0.1.190 shipped in November, 2003
EzZip Suitcase Rate
This product bills itself as the “Ultimate Multilingual User Friendly” compression tool. The usual Zip features plus support for six different languages. Fifteen day free trial download.
Reader Donald J. says Excellent zip utility and definitely the easiest I have ever used.
ZipCentral Rate
ZipCentral is a free and easy to use zip file manager with all the utilities you need to manage your zip files. The goal of ZipCentral is to be the most robust freeware zip-package you can find today. It is a great tool for the beginner as well as the expert. Working with zip files has never been easier!
Zipserver Rate Zipserver is a little HTTP server that serves up static documents from inside Zip files. Great way to put manuals or archived documents on line, don’t you think?
SimplyZip Rate There are two programs named SimplyZip. This is the free one from Germany. This program has an awesome list of supported archives formats.
Version 1.1 is shipping as of June, 2004
QuickZip Rate The software reviewer at the SlaughterHouse speculated that commercial developers of zip programs ought to just pack it in when they see how good QuickZip is. If you agree or disagree, why not post an evaluation here so we can benefit from your experience? It seems to be free, plus has support for Chinese and several European languages.
Release 3.05 is shipping as of November, 2003.
ZipFusion Rate A free self-extractor bundler, it can take a standard Zip file and convert it into a self-extracting EXE, or take a self-extracting EXE and turn it into a Zip file. Free for non-commercial use, lots of nice new features in the 2.0 release.
Version 2.0 is shipping as of May, 2004.
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GIF – Compuserve’s Graphics Interchange Format

In the late 80s Compuserve was the dominant Online Information Service. As such, they created a standard for graphics files called the Graphics Interchange Format, or GIF. Because of their influence, the GIF file format soon became very popular. When the first WWW browsers supported GIF fiels, the format became even more popular.
GIF is documented here because it relies on LZW compression is used to store image data internally. This became an important fact after Unisys decided to start imposing patent royalties on developers who created programs that created or displayed GIF files

[ Deja News ] Search compression newsgroups for references to this topic
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Amazon Honor System
Books

Compressed Image File Formats: JPEG, PNG, GIF, XBM, BMP by John Miano Rate
“Compressed Image File Formats is an appealingly compact and useful guide to some of today’s most popular file formats used for image data. For any programmer who needs to know how images are stored, this concise reference can serve as a really invaluable resource.”
Note that the source code for this book includes an independent implementation of a PNG codec, which may be one of a kind. Link to the source code on this page.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Commercial Libraries

Arcsoft Mobile Media Codecs Rate Arcsoft has a line of mobile media codecs that includes support for MIDI, JPEG, PNG, GIF, and speech.
Commercial Programs

Trout’s GIF Optimizer Rate
This freeware program is designed to help you reduce the size of your GIF files. There are certain optimizations that can be performed with absolutely no loss of quality, as well as some that can provide additional improvements with some loss of resolution. Best of all, Trout’s GIF Optimizer is completely free.
An anonymous reader complained They call it freeware then make you pay. To be honest, I can’t see any indication of this on the web site, other than the usual request for donations. Somebody correct me if I’m wrong!
GIF Construction Set Pro Rate GIF Construction Set Pro represents the state of the art in GIF animation software. It will assemble your original animations effortlessly through its Animation Wizard, squeeze them down to as close to nothing as possible with its Supercompressor; create eyecatching banners and animated transitions; manage your GIF files; add transparency to existing graphics and a lot more.
Version 2.0.44 is shipping as of February, 2004.
Ultra GIF Optimizer Rate Ultra GIF Optimizer is a powerful tool for optimizing GIF images. It can makes your web page load faster,save your server bandwidth charges and disk space! This is a commercial product, but it looks like you can download it and have a trial session.
Real GIF Optimizer Rate A GIF optimizer seeks to reduce the size of your GIF files, usually without compromising image quality. Not enough detail on this site to pass judgment, but good GIF optimizers will also let you reduce the number of colors in the palette dynamically, so you can see the effect.
Real GIF Optimizer 3.05 shipped in February of 2003. I wish I could tell you what new features are in this release, but RealMultiMedia Development is one of those companies that doesn’t bother to post release notes on their web site!
Advanced GIF Optimizer Rate This program is designed to help you squeeze the maximium amount of space out of GIF files while keeping the image quality at an acceptable level. Commercial code, but a free download is available.
Version 4.0 is shipping as of December, 2003.
Links

Web Graphics Rate A tutorial page discussing the various image formats currently in use on the web. Nice comparisons and a good set of links.
Working with GIF images in Delphi Rate A straightforward article with some discussion and links.
Non-Commercial Libraries

Corona Rate
Corona is an image input/output library that can read, write, and manipulate image files in just a few lines of code. It can write PNG files, and read PNG, JPEG, PCX, BMP, TGA, and GIF. Corona was designed to be easy to use, and exports a straightforward C++ API. With just a few lines of C++, you can add image loading to your application.
Corona 1.0.1 shipped in May, 2003, and added support for TGA images as well as a few more functions.
True-Color GIF Example Rate
Yes, it is possible to create GIF images with far more than 256 colors. This page will show you exactly how that is done, or at least prove to you that it is possible. It links to a GIF library called ANGIF that purports to be able to pull this trick off.
zlib and libpng for Windows CE Rate Kazuo Adachi ported both of these important packages to Windows CE and Windows CE .Net. This includes binaries for what I believe are all the currently support CPUs.
Libungif – An uncompressed GIF library Rate A library for reading and writing gif images. The save functionality uses an uncompressed gif algorithm to avoid the Unisys LZW patent. This library is based on Eric Raymond’s giflib and implements a superset of that library’s API.
Version 4.1.2 of this library shipped in March, 2004.
Non-Commercial Programs

InterGif Rate
InterGIF is a freeware program for making animated GIFs. It claims to do a good job of optimization. I have feedback from one use who was quite happy with the results – a sample GIF created by GIMP was reduced from 2235 bytes to 1455. Not bad.
(X)MedCon – Medical Image Conversion Utility Rate
A free program to deal with image formats in popular medical formats, including DICOM, SPM, PNG, and GIF.
Version 0.9.1 of (X)MedCon shipped in January, 2004.
Gif2Png Rate Convert your GIF files to PNG format under UNIX, Linux, or Win32.
Scilab Image Processing Toolbox Rate SIP intends to do imaging tasks such as filtering, blurring, edge detection, thresholding, histogram manipulation, segmentation, mathematical morphology, color image processing, etc. These operations are useful for problem solving in real-world applications ranging from car motion planning to automatic diagnosis of medical images.
Version 0.3.1 is shipping as of May, 2004.
Papers/Documentation

The GIF Controversy: A Software Developer’s Perspective Rate Some thoughts by a person only known as mcb on the GIF patent controversy.
Patents/Licenses

License Information on GIF and Other LZW-based Technologies Rate
A Unisys press release explaining their beliefs regarding licensing required to use GIF technology in your products. As of this posting (8/2003) the US patents appear to have expired, but there are European and Japanese patents will not expire until some time in 2004.
Source Code

Add GIF-animation to your MFC and ATL projects Rate Decoding GIF files and displaying them without help isn’t particularly easy. Add animation to the task and you’re looking at a ton of work. Fortunately, this MFC-compatible set of classes on the CodeProject web site does the heavy lifting for you.
Standards

GIF89A Specification Rate
This is a copy of the second GIF specification from CompuServe. It added quite a few features to the GIF format. Probably the best well known of these would be the ability to add animation to GIF files.
Reader Andrew T. says: The definitive document, what more can you ask for?
GIF89A Specification Rate Another copy.
GIF87A Specification Rate This is a copy of the original GIF specification from CompuServe. It was expanded significantly by the 1989 specification.
GIF89a Animation Browser Test Rate These pages will test the various features available for GIF89a animation. Each feature is tested as independently as possible, allowing you to identify what features your browser supports and how well. The pages isolate features to prevent combination collisions (one error causing another feature to fail). Each test is composed of an animation that tests the most basic quality of the function.
Tutorials, Reference, Presentations

Lzw, gif decoding Arturo Campos describes the specific implementation of LZW compression used in GIF files.
True-Color GIF Example Rate
Yes, it is possible to create GIF images with far more than 256 colors. This page will show you exactly how that is done, or at least prove to you that it is possible. It links to a GIF library called ANGIF that purports to be able to pull this trick off.
Additional GIF format documentation Rate Royal Frazier’s All About GIF89a, a bountiful page of documentation on the file format.
Wikipedia Entry: GIF Rate The Wikipedia entry for GIF. A reasonable amount of background and overview information.
Replacing a Dictionary with a Square Root Rate Tom Cagill creates GIF files without using LZW.
Web Graphics Rate A tutorial page discussing the various image formats currently in use on the web. Nice comparisons and a good set of links.
Compression, Encoding and Graphics Files – A Practical Tutorial Rate Tutorial by Rich Holowczak from Rutgers U. A set of slides that would probably be really useful if you had the lecture to go with it. Without the lecture, not so hot.
LZW and GIF explained Rate A guy named Steve Blackstock takes a shot at making this all clear to you. Gives some details on the LZW variation used in GIF files.
Working with GIF images in Delphi Rate A straightforward article with some discussion and links.
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Gzip

Gzip is a free compression program and format. It uses the same deflate compression engine that Zip-compatible programs use, but does not archive multiple files. Gzip is often used in confunction with tar – tar combines a group of files into a single archive, then gzip compresses the result.
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Commercial Libraries

Xceed Zip for .NET Compact Framework Xceed Zip for .NET Compact Framework is a data compression and all-purpose file manipulation class library for creating mobile apps. It provides flexible zip, gzip and streaming data compression capabilities for compact applications created with Visual Studio .NET 2003. The library includes an innovative and extensible filesystem object model that makes zip files as easy to work with as regular files or folders.
Xceed Streaming Compression for .NET Xceed Streaming Compression for .NET is an efficient and lightweight data compression class library for Microsoft .NET and ASP.NET. It can process any size byte array with ease and provides a true .NET pass-through stream object for automatically compressing or decompressing any .NET stream’s data on the fly. It supports the GZip, Zlib, Deflate and Deflate64 compression formats.
IP*Works! Zip Component Suite Rate IP*Works! Zip allows developers to easily integrate compression and decompression functionality into web or desktop applications using popular file and data compression standards including Zip, Tar, Gzip and Jar standards for compression. All IP*Works! Zip components have been built from the ground up entirely in native .NET and Java code, combining exceptional speed, excellent data compression, and extreme portability across platforms.
The components feature password support, file deletion within an archive, streaming compression and decompression, and more. IP*Works! Zip is currently available as fully-managed 100% C# .NET components, or pure Java beans.
Commercial Programs

UUNet FTP Site Rate
This ftp site has copies of Zoo, ARC, gzip, and zip, in some cases for multiple platforms.
GZIPSite Rate GZIPSite is a tool that can compress your web site and allow it to load as much as 50% faster.
HTML2Zip Rate This product compresses your web pages using the gzip format, which is readable by virtually every modern browser. Compressing the pages this way can do a lot to improve your page loading times.
Version 2.0 is shipping in April, 2003.
Japanese Language Resources

Easy-GZ Rate Easy-GZ is a compression tool which allows extremely tight compression and quick decompression. Based on the GZip standard and optimized for the Macintosh platform, an easy-to-use, effective GZ compressor has finally been brought to the Mac OS. Is this software free or not? I’m putting it in the free category – if you find out otherwise please send me an email.
Non-Commercial Libraries

GZipHelper Rate
This nice post on the CodeGuru web site does Gzip compression to and from memory, instead of to and from files.
The Zip, GZip, BZip2 and Tar Implementation For .NET Rate
#ziplib (SharpZipLib, formerly NZipLib) is a Zip, GZip, Tar and BZip2 library written entirely in C# for the .NET platform. It is implemented as an assembly (installable in the GAC), and thus can easily be incorporated into other projects (in any .NET language). The creator of #ziplib put it this way: “I’ve ported the zip library over to C# because I needed gzip/zip compression and I didn’t want to use libzip.dll or something like this. I want all in pure C#.”
Visitor Samuel L. had this to say Extremely useful and well written, well done, great that is open source.
CGZip, a C++ wrapper for gzip methods Rate This wrapper class provides you with simple access to the gzip compression methods in zlib. You can compress and decopress to/from memory (including strings) to files. Looks promising. Release 1.1 was released 12/2002, although I can’t tell what if anything has changed.
Non-Commercial Programs

Gzip Rate
The source repository for gzip.
MacGzip Home Page Rate
Links and information about MacGzip
UUNet FTP Site Rate
This ftp site has copies of Zoo, ARC, gzip, and zip, in some cases for multiple platforms.
Easy-GZ Rate Easy-GZ is a compression tool which allows extremely tight compression and quick decompression. Based on the GZip standard and optimized for the Macintosh platform, an easy-to-use, effective GZ compressor has finally been brought to the Mac OS. Is this software free or not? I’m putting it in the free category – if you find out otherwise please send me an email.
WinGzip Rate WinGZip is an small freeware utility for working with files produced by gzip utility (usually it’s files with .gz or .tgz extension) and also create such files. Main features include the compressing, decompressing and testing the integrity of gzip files.
mgzip Rate mgzip is a program that makes use of SMP machines and zlib to use as many processors as you have to quickly compress files into gzip compatible format. mgzip only compresses; gunzip must be used to uncompress the resultant file. I have been able to compress files three times faster than standard gzip on a 4 processor Alpha 4100 using three worker threads. Currently, mgzip will compile and run on Digital Unix 4.0[BD], Linux with a suitable pthread library, and AIX 4.3. Porting to other Unices with pthread libraries should be an easy task, and may be as simple as compiling.
UFUP Rate UFUP advertises itself as a “decompression utility that handles common Unix package formats such as bzip2, gzip, and tar.”
Papers/Documentation

Gzip specification in PS format Rate
The gzip technical specification in US size PostScript, by L. Peter Deutsch.
Gzip specification in ASCII format Rate
The gzip technical specification in ASCII, by L. Peter Deutsch. This document is the basis for RFC 1952.
GZIP file format specification version 4.3 Rate
The gzip technical specification in HTML, by L. Peter Deutsch. This document is the basis for RFC 1952. Includes sample CRC code
Source Code

Gzip Rate
The source repository for gzip.
GZIP file format specification version 4.3 Rate
The gzip technical specification in HTML, by L. Peter Deutsch. This document is the basis for RFC 1952. Includes sample CRC code
Standards

GZIP file format specification version 4.3 Rate
The gzip technical specification in HTML, by L. Peter Deutsch. This document is the basis for RFC 1952. Includes sample CRC code
GZIP File Format Rate
Peter Deutsch’s description of the GZIP file format.
Tutorials, Reference, Presentations

Lesson Eight: Archiving Utilities Rate This is apparently part of a *NIX manual. Teaches you about our good friends tar, gzip, and bzip2.
Compress Your PHP4 Pages Rate Gzip encoding is a great way to serve up your web pages, because all modern browsers can render this format. If you’re creating pages with PHP4, it turns out to be really easy to compress your pages this way and get a bit of speedup.
Wikipedia entry: Gzip Rate The Wikipedia entry for Gzip. Very short with just a couple of links.
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Hardware

Compression is addressed in hardware just as well as in software. This topic covers implementations of compression in chips, devices, etc.
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Arithmetic Coding

The Qx-coder Rate
IBM’s implementation of arithmetic coding known as the Q-coder is a well-known piece of work. (Patented, unfortunately.) This paper discusses an implementation of the Q coder in hardware.
Data Compression

Fourelle Systems Rate Fourelle Systems, Inc.is the global market leader in accelerated content delivery. Venturi, Fourelle’s flagship product platform, speeds the performance of IP applications over WAN links including T1, frame relay, satellite, wireless, cable and dial-up. Venturi uses application level compressionand an optimized transport protocol to achieve up to 400% performance gains.
Esoterica/Miscellany

IBM research breakthrough doubles computer memory Rate IBM has created a chip that appears to be able to dynamically compress data as it is being written to RAM. Details sketchy in this news release.
Image Compression

Tak’Asic Rate
Tak’Asic provides Lossless/Lossy still image compression/decompression ICs solution.
. Our ICs support JBIG, MH, MR, MMR and JPEG standards.
Our latest product, Tak’B3, is the world fastest JBIG codec available. It is able to process images at 133Mpixel/sec minimum and up to 2128Mpixel/sec. It also provides code conversion (MR/MR/MMR <-> JBIG) and scaling functionality.
Internet

Expand Networks Rate
Expand makes a series of Network Accelerators. These are black boxes that perform lossless compression on packets being shipped across our WAN. Lots of competition in this area, so companies like Expand depend on innovative and proprietary techniques to give them an edge.
Peribit Rate
These folks make a box that transparently compresses network traffic. Designed to work on any sort of WAN interface, including T1, E1, ATM, etc. The web site includes an ROI calcuator that will convince you this box will pay for itself!
ITWorx Rate These folks make NetCelera, a WAN compression product.
JBIG

The Qx-coder Rate
IBM’s implementation of arithmetic coding known as the Q-coder is a well-known piece of work. (Patented, unfortunately.) This paper discusses an implementation of the Q coder in hardware.
Tak’Asic Rate
Tak’Asic provides Lossless/Lossy still image compression/decompression ICs solution.
. Our ICs support JBIG, MH, MR, MMR and JPEG standards.
Our latest product, Tak’B3, is the world fastest JBIG codec available. It is able to process images at 133Mpixel/sec minimum and up to 2128Mpixel/sec. It also provides code conversion (MR/MR/MMR <-> JBIG) and scaling functionality.
JPEG

DSPWorx Cheetah – DSW2000S Chip Rate
This System-on-chip provides you with all the building blocks you need to perform several different kinds of compression and decompression, including MPEG, JPEG, and JPEG2000.
Tak’Asic Rate
Tak’Asic provides Lossless/Lossy still image compression/decompression ICs solution.
. Our ICs support JBIG, MH, MR, MMR and JPEG standards.
Our latest product, Tak’B3, is the world fastest JBIG codec available. It is able to process images at 133Mpixel/sec minimum and up to 2128Mpixel/sec. It also provides code conversion (MR/MR/MMR <-> JBIG) and scaling functionality.
TI sampling encoding chips for digital cameras Rate TI is pushing its ARM and DSP cores into the digital camera market, with chips that support conventional imaging as well as MPEG-2 and MPEG-4 video.
Oak Technology JPEG Image Processor Rate The PM-36 is a chip that is touted as processing up to 110 MB of data per second. Oak says it is suitable for copiers, printers, scanners, etc.
Zoran Corporation Rate Zoran makes chips that do some MPEG decoding as well as JPEG codecs.
ViCAM®-III Digital Imaging Engine Rate Vista Imaging makes this chip, designed to do the image processing needed for several different types of digital cameras. Among many other features, it has a JPEG compression engine.
divio Rate Self-described leader in digital video and imaging technology, divio has a product line that includes hardware that implements MPEG-4, AAC, M-JPEG, and JPEG. Suitable for inclusion in both digital still and movie cameras.
JPEG-2000

DSPWorx Cheetah – DSW2000S Chip Rate
This System-on-chip provides you with all the building blocks you need to perform several different kinds of compression and decompression, including MPEG, JPEG, and JPEG2000.
TI releases DSP Developer Support for JPEG2000 Rate
Texas Instruments announced the release of a DSP based Image Developer’s Kit, with support coming for JPEG2000, MPEG-4, and other standards.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
JPEG2000 Bi-directional Image Coprocessor Chip Rate Analog Devices makes a JPEG2000 processor that can process better than 10 Megapixels per second. This chip is targeted towards the digital still camera market. You can find a press release on the page that says initial pricing is $14 in 10K quantities.
JPEG200 In Accelerator Chip Rate Analog Devices has announced an acceleratory chip that supports the JPEG2000 image compression format. The chip is targeted towards digital still cameras, and is available now for $14 in quantitites.
FREE Print Subscriptions Printer friendly versionEmail a Colleague Star IP Cores Target ASIC/FPGA Implementation Rate Amphion Semiconductor has announced the development of ASIC- and FPGA-targeted versions of the company’s hardware-accelerator cores for MPEG-4, MPEG-2, and JPEG2000 compression applications. The new “Star IP” cores are also equipped with AHB interfaces that are compatible with the AMBA specification for on-chip system bus connectivity.
Chinese JPEG2000 business on runway Rate This article in EE Times describes an effort to steer the Chinese digital camera business onto the JPEG-2000 road. The goal is to create a chip that can be inserted into cameras for less than $10. The supplier of the algorithm used in the chip is WIS Technologies.
Lossless Compression

Hi/fn, Inc. Rate
Hi/fn makes lossless compression hardware and software. They have a bunch of chips that implement LZS and MPCC compression, plus a library that does the same thing. I have been led to believe that these algorithms are partially or completely protected by patents.
Real-Time Lossless Compression Systems Rate
Some folks at Loughborough U. are working on attempts to integrate data compression more closely with computer hardware. This page has reports on their progress, as well as links to some of their papers.
DCP Research Rate
DCP’s unique compression algorithm, the GCA, achieves significantly higher compression ratios than Stac Electronics’ LZS–typically 20% to 80% better. This difference is only a total of tens to hundreds of dollars for storage situations, but it can save hundreds of dollars a month on a leased communication link.
GEMAC Rate This company sells an IP core that performs lossless data compression. Not sure what algorithm they are using, it is described as “GEMAC’s data compression algorithm.” This algorithm was first published at DCC ’95, and is described as a hybrid of ZL1 and ZL2, created with the goal of maximizing compression rate.
X-Match Pro Rate A fast ASIC core designed for lossless compression.
Data compression technology in ASIC cores Rate A paper from the IBM R&D group discussing the use of lossless compression in hardware.
SA-Comp/1 and SA-Comp/4 Data Compression SA Rate Cisco makes a box you can attach to their routers. The box performs lossless data compression.
IBM research breakthrough doubles computer memory Rate IBM has created a chip that appears to be able to dynamically compress data as it is being written to RAM. Details sketchy in this news release.
Parallel Implementation of Data Compression Technologies for Multi-Gbit/s Networks Rate This group at Loughborough University in the UK would like to use sophisticated compression techniques in high speed networks. To make it all happen, they need to do it in hardware, and do it in parallel. This page has information about their efforts, along with links to papers and other information.
MP3/MPEG Audio

WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
Hardware Support for MP3Pro Rate EE Times reports that both TI and SMT are making chips that support the new MP3Pro format, clearing the way for its inclusion in portable audio devices.
Stream Machines Selling MPEG-2 Chip Rate Stream Machines is selling a dedicate chip that will decode MPEG-1, -2, and -3, along with MP3 and other standards. The chip will be roughly $35 in quantity.
OpenJaz Rate Driver and software for the jazPiper(tm) MP3 player.
MP3elf – Network MP3 Player Rate The MP3elf is a low-cost Ethernet connected MP3 player that receives a MP3 stream from a local area network server and delivers it to amplified speakers or a Hi-Fi system. You can have a single source of MP3 files in your home or office, and browse through playlists from any MP3elf. The Universal IR receiver allows the MP3elf to respond to one of your existing Remote Controls (or use the on-board pushbuttons) and the LCD interface can display your very own choice of information. The elfServer software design allows compatibility with a range of different front-end options. As it is Java based, it can run on Windows, Macintosh, or Linux machines.
MPEG

Agilent (formerly HP) Rate
MPEG test equipment. The test/measurement arm of HP was spun off into a new company called Agilent. They make test gear so you can check your MPEG compliance.
Pentamedia Rate
Among other things, these folks make a MPEG 1/2 A/V encoder board for your PC. As an added bonus, their site comes in English, Spanish, and Korean versions.
DSPWorx Cheetah – DSW2000S Chip Rate
This System-on-chip provides you with all the building blocks you need to perform several different kinds of compression and decompression, including MPEG, JPEG, and JPEG2000.
Matsushita MPEG-4 chip encodes/decodes multiple objects Rate
EE Times reports on a hardware implementation of the MPEG-4 standard.
TI releases DSP Developer Support for JPEG2000 Rate
Texas Instruments announced the release of a DSP based Image Developer’s Kit, with support coming for JPEG2000, MPEG-4, and other standards.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
Toshiba licensing MPEG-2 Codec Rate EETimes has an article about this new single-chip MEPG-2 codec built around Toshiba’s Media Embedded Processor architecture.
TI sampling encoding chips for digital cameras Rate TI is pushing its ARM and DSP cores into the digital camera market, with chips that support conventional imaging as well as MPEG-2 and MPEG-4 video.
Breathe MPEG-4 life into antique computers Rate Want to play MPEG-4 videos on that creaky old P166 collecting dust in some corner of your office? It’s not as crazy as you might think. This article from Tom’s Hardware shows you exactly how to go about it. The secret isn’t some hot new codec. Rendering MPEG-4 streams at high resolutions requires a CPU that’s peeking up into GigaHertz territory, and nothing is going to change that. Nope, what you need is a relatively inexpensive hardware decoder from Sigma Designs. This board uses a RealMagic decoder chip on PCI card, and makes the whole thing happen for under $100
Motorola MPEG-2 Encoders Rate This page details products from Motorola’s Broadband Communications Sector, which includes MPEG-2 encoders used in satellite broadcast technology.
VisionTech Ltd. Rate MPEG encoding hardware, chips and boards.
LSI Logic / C-Cube Microsystems. Rate C-Cube makes hardware and software encoder and decoders for MPEG video and audio.
C-Cube was engulfed by LSI Logic in 2001, you can now find all of their products here, probably under Professional Codecs and Consumer Products.
Sigma Designs Rate Sigma makes hardware MPEG decoders. You might need one of these if you’re designing a set-top box or a new PC video card.
Stream Machines Selling MPEG-2 Chip Rate Stream Machines is selling a dedicate chip that will decode MPEG-1, -2, and -3, along with MP3 and other standards. The chip will be roughly $35 in quantity.
Toshiba VideoPhone MPEG-4 IC Rate Toshiba announces silicon suitable for building an MPEG-4 based videophone. Pretty nice looking piece of work, shipping in Q42K.
Zapex Rate Zapex makes chips, chip cores, and boards dedicated to real time compression, including MPEG-2 and AC3.
Precision Digital Images Rate This company makes digital video streaming hardware and software. Although it looks like maybe they don’t actually make the hardware, they help you design it.
Tiernan Communications, Inc. Rate These folks sell a couple of boxes that do MPEG-2 encoding. Looks like they are oriented towards the video broadcasting business.
Zoran Corporation Rate Zoran makes chips that do some MPEG decoding as well as JPEG codecs.
MagicEyes MMSP-2 Rate The MMSP-2 chip has been developed by MagicEyes for use in consumer products. It can decode MPEG-1, -2, and -4 as well as various audio codecs. While you’re asking, yes, it has an LCD controller, a Poly Wavetable sound synthesizer, and more.
DirectX VA Rate Microsoft is providing a Microsoft® DirectX® application programming interface (API) and a corresponding device driver interface (DDI) for acceleration of video codec processing. This API/DDI provides an interface definition focused on support of MPEG-2 “main profile” video (formally ITU-T H.262 | ISO/IEC 13818-2), but also intended to support other key video codecs (ITU-T Recommendations H.263 and H.261, and MPEG-1 and MPEG-4). The interface is designed to extract the most basic computationally-intensive building-blocks of these various codec designs and support their acceleration in hardware.
Conexant Intros Low Power MPEG-2 Encoder Rate Conexant Systems has introduced new low power MPEG-2 audio/video encoder that incorporates the functionality of up to three different chips in a single device, a feat that the company claims will enable designers to improve video quality while simplifying their designs and reducing manufacturing costs.
FREE Print Subscriptions Printer friendly versionEmail a Colleague Star IP Cores Target ASIC/FPGA Implementation Rate Amphion Semiconductor has announced the development of ASIC- and FPGA-targeted versions of the company’s hardware-accelerator cores for MPEG-4, MPEG-2, and JPEG2000 compression applications. The new “Star IP” cores are also equipped with AHB interfaces that are compatible with the AMBA specification for on-chip system bus connectivity.
XCode Video Networking Processor Rate ViXS Systems from Toronto, Ontario has announced the XCode chip, which they say will adjust MPEG formats, bit rates, and resolutions on the fly as data moves through an IP network. At a minimum, this means the part can format MPEG1 to MPEG2 to MPEG4, and change resolutions from QCIF to standard to high definition and back again, depending on network bandwidth availability.
divio Rate Self-described leader in digital video and imaging technology, divio has a product line that includes hardware that implements MPEG-4, AAC, M-JPEG, and JPEG. Suitable for inclusion in both digital still and movie cameras.
Speech

Digital Voice Systems Inc. Rate
This company makes the AMBE-2000, a Vocoder chip that compresses speech down to a miniscule 4 Kbps. They have an additional product library of low bit-rate codes both in hardware and software.
Nuera Products Rate
Nuera makes a couple of speech multiplexers that use CELP compression. You probably won’t be interested in these unless you’ve got a T1 line that is bursting at the seams.
Video

VisioWave Rate
VisioWave is offering simple, modular, integrated and open-ended high-quality and reliable hardware and software solutions for compression, processing and real-time transmission of very high quality video over any network (IP, ATM, ADSL, cable, wireless, …).
Nancy codec to give MPEG-4 a run for its money Rate
Nancy is the name of a lightweight video codec being used to send video email in the J-Phone design in Japan. The proprietary algorithm uses something called the Structured Meta Scale Polygon to compress data with fewer MIPS than its competition. Nancy can compress and decompress 30 fps at QCIF resolution with as little as 50 MIPS, using on ly 30-49Kbytes of memory.
4i2i Communications Systems Rate These folks make H.261 and H.263 codecs for applications that need video compression. They have source and object software for the PC, as well as IP versions of their hardware design. The web site is reputed to have demo versions of some of their software.
STMicro and 8×8 to team on video chips Rate EE Times reports that Europe’s ST Microelectronics is teaming up with 8X8 Inc. to produce chips aimed at the IP Telephony market. They are hoping to create chips that will be used in network video applications.8X8 will be supplying advanced compression and decompression algorithms for the chip vendor to sell in silicon.
Pulsent promises bang-up video compression Rate Privately held Pulsent is promising a new video compression technique that can stream video across the net with only half the bandwidth of MPEG2. They’ve not only created a new algorithm but are also developing the chips to support it.
Sorenson Vision Rate Sorenson makes hardware and software for video conferencing and other video streaming apps.
Precision Digital Images Rate This company makes digital video streaming hardware and software. Although it looks like maybe they don’t actually make the hardware, they help you design it.
WIS Technologies announces PC Video chip Rate EE Times carries this announcement of a new PC video encoder chip from WIS Technologies. The chip is designed to do the heavy lifting that is real trouble for a host CPU, by taking care of things like DCTs and motion estimation. It relies on that same host CPU to do format conversion and other more mundane tasks. The chip currently supports video formats that include DiVX, H.261, H.263, MPEG-2, and more
DemoGraFX to offer imaging IP cores in strategy shift Rate DemoGraFX Inc. is going to be selling their video compression technology to semiconductor companies and system vendors. EE Times has the scoop.
Wavelets

VisioWave Rate
VisioWave is offering simple, modular, integrated and open-ended high-quality and reliable hardware and software solutions for compression, processing and real-time transmission of very high quality video over any network (IP, ATM, ADSL, cable, wireless, …).
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
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Huffman Coding

David Huffman developed a form of encoding that creates the most efficient set of prefix codes for a given text. The ease with which Huffman codes can be created and used makes this still an extremely popular tool for compression code.
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Commercial Libraries

UPL Compression : the complete professional toolkit Rate
The UPL Compression Library is a high-performance professional compression library. It offers the ability to compress and decompress data, buffers, strings or single files and features the latest innovations in data compression. The library offers eight extremely powerful compression algorithms. Dynamic Huffman, Arithmetic, BWT, Ppm and several Lempel Ziv flavors.
DataCompression.info user John G. had this to say: I was looking for adding a better compression to my Visual Basic project and it worked like a charm. The compression ratio is really good, better than Zip!
Italian

C Library to search over compressed texts Rate
A team from the University of Pisa in Italy have created a set of two libraries to demonstrate the ability to perform searches in compressed text. The code is packaged as two LGPL libraries: HuffwLib and CGrepLib, and sample programs are available on the site for demonstration purposes.
Links

One to One Compression This site discusses a characteristic of some compression algorithms that the author refers to as One to One compression. In a nutshell, this property means that for any file X, F( F'( X ) ) == X. (F is either the compressor or decompressor, and F’ is its opposite number.) This is definitely not the case for most conventional compression algorithms.
Shannon-Fano Coding Rate
The definition from the NIST Dictionary of Algorithms and Data Structures.
K-ary Huffman Encoding Rate The definition from the NIST Dictionary of Algorithms and Data Structures.
Newsgroup Posts

Huffman codes and Fibonacci numbers by Alex Vinokur Rate
A careful analysis of degenerate Huffman trees created when input counts follow a Fibonacci sequence, by Alex Vinokur. This post is from sci.math.
Canonical Huffman Coder Construction Rate
The first time I ever heard the phrase Canonical Huffman Coder was in reference to the technique used in PKZip to store Huffman tables. I don’t know where the technique originated, but it is basically a way to construct a Huffman table so that the actual codes don’t have to be stored when storing the table. This makes for some nice space savings when compared to a first-pass naïve implementation. (Like the ones I’ve done in the past.)
It turns out that somebody named Gareth was attempting to implement this code but was having a bit of trouble. His post to comp.compression brought out some useful help from some of the newsgroup regulars, and did a lot to shed light on the topic, and includes a reference to the paper that actually gave birth to the concept.

Alex Vinokur Newgroup Posts Rate Alex has collected a series of newsgroup discussions on Huffman coding.
Non-Commercial Libraries

C Library to search over compressed texts Rate
A team from the University of Pisa in Italy have created a set of two libraries to demonstrate the ability to perform searches in compressed text. The code is packaged as two LGPL libraries: HuffwLib and CGrepLib, and sample programs are available on the site for demonstration purposes.
Basic Compression Library Rate
Marcus Geelnard has created a batch of compression routines that you can plug and ply into your programs at will. Marcus is using the wonderfully open zlib license, which means thare are just about no reason you can’t use this code. The 1.0.5 added an LZ77 codec to the RLE, Huffman, and Rice coders
Satisfied user Todd W said: I needed a simple set of compression routines for use in an embedded system. I must be able to store a fair amount of information in a small EEPROM as a generic database. The Huffman coder works very well in the application and has met my needs exactly! Very nice!

Huffman Compression Engine Rate
Huffman Compression Engine with Turbo Pascal Interface.
Huffman.java Rate
Advertises itself as “A dirty but free implementation of a huffman encoder/decoder in Java.” Not completely free, it is covered by the GLPL, and naturally includes fully documented source.
libhuffman – Huffman encoder/decoder library Rate
libhuffman is a Huffman encoder/decoder library and a command line interface to the library. The encoder is a 2 pass encoder. The first pass generates a huffman tree and the second pass encodes the file. The decoder is one pass and uses a huffman code table at the beginning of the compressed file to decode the file.
Beta 3 shipped in October, 2003.
Huffman Compression Engine Rate This program is currently capable of reading and extracting files made with LHA and other utilities that generate .lzh files, from -lh4- to -lh7-. The foundation of the algorithm for this program like ARJ is based on Haruhiko Okumura’s work on ar002, which was the foundation of LHA. Unlike Haruhiko’s work however, the dictionary size is dynamic and currently allows for dictionary sizes of up to 64KB. On larger files, compression of files is usually 0.5% to 5% tighter than PKzip, and work in progress will likely yield even better results. Files created with this utility natively create -lh7- signed archives, which on larger files results in slightly better compression than that of lha32 by Haruyasu Yoshizaki.
Non-Commercial Programs

David Scott’s Bijective Static Entropy Compression Rate
This compressor is designed to operate on English text – it has a static probability table configured for written English.
The shcodec Home Page Rate
shcodec is order-0 32-bit canonical static huffman codec. It encodes an alphabet of 256 symbols with minimum-redundancy or length-restricted codes (basic method: Alistair Moffat and Jyrki Katajainen, modified by Artur A. Pessoa). shcodec uses efficient method for tree packing: on text files packed tree size is approx 68 bytes, on binary files this value is about 132 bytes. Memory requirements are very small: 1280 bytes for encoding and only 574 bytes for decoding! shcodec uses extremely fast and simple SHIFT-OR method for encoding, and CANONICAL-DECODE with a cache for small codewords for decoding.
Update: Alexander has added SH-SFX to the web page – a program for creating Win32 SFXs from files compressed with shcodec.
Image Compression Using Huffman Coding Rate
Tim’s Home Page has three different programs that attempt to compress images using Huffman coding.
HFFzip Rate
A Huffman file compressor for *NIX platforms. The author admits that the compression is perhaps not the best, but says it’s going to be just right for embedded programming because of its miniscule footprint and high speed.
Version 1.01 was shipping in June, 2003.
McKee’s Directed Acyclic Graph Compression Rate Will McKee has released this as freeware – includes complete source to a string substitution compressor. From the description it sounds as though it’s variant on LZSS, but I’ll defer to anyone willing to do a real analysis.
BAR Rate BAR Archiver is a free, cross-platform file compression and archiving tool written in Java. It outperforms most of the popular file compression tools available as commercial utilities. Compression is based on Burrows Wheeler Transformation and modified Huffman entropy coder. The compression ratio is in par with most of the commercial grade compression utilities.
bwtzip: A Linear-Time Portable Research-Grade Universal Data Compressor Rate bwtzip is an ongoing project, distributed under the GNU General Public License, to implement a Burrows-Wheeler compressor in standard, portable C++. It is research-grade in that it is highly modularized and abstracted, so that it is simple to swap out parts of the compressor without affecting anything else. This makes it easy to experiment with different algorithms at different stages of compression.
Looks like Steven T. Lavavej released a new version of bwtzip in early February, 2003. A wide variety of improvements, most of them in implementation – not visible to the end user. A description of recent changes is found here
Papers/Documentation

A Method for the Construction of Minimum-Redundancy Codes Rate
The famous paper by David Huffman, as originally published in the Proceedings of the I.R.E.
In-Place Calculation of Minimum-Redundancy Codes Rate
The abstract for a paper on calculation of Huffman codes. The paper isn’t here, but the source code is. Alistair says that if you sort your array of counts, you can create the Canonical Huffman tree in memory.
Welcome to the Binary Huffman Coding demonstration Rate
Another java graphical demonstration of Huffman tree building.
Proof of Theorem 3.7 The Huffman tree is optimal. Rate
A nice tidy proof that the Huffman tree is an optimal prefix code for a given message. Note that a library reader finds that there is an error in the fixed-length codes listed in Table 1, a and b have duplicate values.
Huffman encoding Rate
The definition from Paul E. Black’s dictionary.
Huffman Coding of ACIS Pixel Data Rate ACIS, the AXAF CCD Imaging Spectrometer, is an instrument being built by a team from the Massachusetts Institute of Technology’s Center for Space Research and the Pennsylvania State University for the Chandra X-ray Observatory (formerly, AXAF), scheduled for launch in 1999.
This is a good paper discussing practical implementation of data compression in a real world project with interesting parameters.

Optimized Morse Armor Rate John Savard develops an algorithm for optimally encoding messages when forced to use nothing but Morse code.
Sub-Linear Decoding of Huffman Codes Almost In-Place Rate A paper by Andrej Brodnik and Svante Carlsson. A data structure that lets you decode Huffman streams super-duper quick.
Parallel Lossless Image Compression Using Huffman and Arithmetic Coding Rate by P. G. Howard and J. S. Vitter. This paper shows how images can be encoded and decoded using parallel processing. Both Huffman and arithmetic coding are examined.
Fyffe Codes for Fast Codelength Approximation Rate Graham Fyffe proposes a variable length integer code that he says is easier to compute than Huffman codes.
Selective Extension Coding Rate Graham Fyffe proposes an alternative type of variable length coding that he claims will offer improved efficiency. Full description, no implementation.
Huffman-Ricardo Coding Rate Daniel Ricardo has a new algorithm for generation of Huffman codes. He claims superior performance and small memory footprint. Algorithm description here, but no code.
Improved Huffman coding using recursive splitting. Rate This page contains a paper that describes a program that attempts to improve on Huffman compression by manipulation of the data stream.
People

David A. Huffman Rate
One of the faculty pages at UC Santa Cruz, the late David A. Huffman.
Eminent UCSC computer scientist David Huffman dies at age 74 Rate
David A. Huffman, the founding faculty member of the Computer Science Department and a pioneer in the field, died at a local hospital on Thursday, October 7, after a 10-month battle with cancer. He was 74.
Russian

Compression and Encryption Sources Rate Links to a variety of lossless coders, includes source for Huffman, arithmetic, LZSS, and other compressors.
Source Code

Huffman Coding with Priority Queues This article is really about using the priority queue containers that are part of the standard C++ library. The example program implements a Huffman Encoder using the queues, showing how they can do a fairly complex piece of work without too much coding on your part.
David’s Compression Page This page has a some Huffman compression code that has been adapted to implement a unique property that author refers to as one to one compression. In a nutshell, this property means that for any file X, F( F'( X ) ) == X. (F is either the compressor or decompressor, and F’ is its opposite number.)This is definitely not the case for most conventional compression algorithms.
Michael Dipperstein’s Huffman Code Page Michael Dipperstein describes his personal quest for understanding an implementation of Huffman coding. Full source included.
The page was updated with new source December, 2002.
Context-based, Adaptive, Lossless Image Coder (CALIC) (Huffman) Rate
Xiaolin Wu’s static Huffman coding version of this program. Free of charge for research and non-commercial use. A total of 1.2 MBytes in a dozen or so files.
David Scott’s Bijective Static Entropy Compression Rate
This compressor is designed to operate on English text – it has a static probability table configured for written English.
Basic Compression Library Rate
Marcus Geelnard has created a batch of compression routines that you can plug and ply into your programs at will. Marcus is using the wonderfully open zlib license, which means thare are just about no reason you can’t use this code. The 1.0.5 added an LZ77 codec to the RLE, Huffman, and Rice coders
Satisfied user Todd W said: I needed a simple set of compression routines for use in an embedded system. I must be able to store a fair amount of information in a small EEPROM as a generic database. The Huffman coder works very well in the application and has met my needs exactly! Very nice!

n-ary Huffman Template Algorithm Rate
Some C++ template code implementing a Huffman algorithm by Alex Vinokur.
DMC.C Rate
Software implementing a complete DMC codec, plus code for a couple of different arithmetic encoders, and a linear time Huffman tree builder.
This program implements Dynamic Markov Compression (DMC) as described in “Data Compression using Dynamic Markov Modelling”, by Gordon Cormack and Nigel Horspool in Computer Journal 30:6 (December 1987). The Guazzo arithmetic coder is used here.

The shcodec Home Page Rate
shcodec is order-0 32-bit canonical static huffman codec. It encodes an alphabet of 256 symbols with minimum-redundancy or length-restricted codes (basic method: Alistair Moffat and Jyrki Katajainen, modified by Artur A. Pessoa). shcodec uses efficient method for tree packing: on text files packed tree size is approx 68 bytes, on binary files this value is about 132 bytes. Memory requirements are very small: 1280 bytes for encoding and only 574 bytes for decoding! shcodec uses extremely fast and simple SHIFT-OR method for encoding, and CANONICAL-DECODE with a cache for small codewords for decoding.
Update: Alexander has added SH-SFX to the web page – a program for creating Win32 SFXs from files compressed with shcodec.
Dynamic Huffman Coder Rate
This dynamic Huffman coder from Karl Malbrain is written in C and includes weight scaling. It is modeled on the Vitter algorithm.
A DataCompression.info user notes that this site has been undergoing continual changes, and perhaps would benefit from some sort of “last modified on” field.
Statistical Coders Rate
A group of statistical coders from Charles Bloom. This includes several different entropy encoders, including Huffman, Adaptive Huffman, CACM Arithmetic coding, and a Skew Coder.
Will’s Huffman Demo Rate
Will McKee wrote some Huffman code in C++. Take a look.
Update: Will reports that he has improved the documentation in this package, as well as adding a new function.
In-Place Calculation of Minimum-Redundancy Codes Rate
The abstract for a paper on calculation of Huffman codes. The paper isn’t here, but the source code is. Alistair says that if you sort your array of counts, you can create the Canonical Huffman tree in memory.
Huffman.java Rate
Advertises itself as “A dirty but free implementation of a huffman encoder/decoder in Java.” Not completely free, it is covered by the GLPL, and naturally includes fully documented source.
libhuffman – Huffman encoder/decoder library Rate
libhuffman is a Huffman encoder/decoder library and a command line interface to the library. The encoder is a 2 pass encoder. The first pass generates a huffman tree and the second pass encodes the file. The decoder is one pass and uses a huffman code table at the beginning of the compressed file to decode the file.
Beta 3 shipped in October, 2003.
In-place Huffman code length calculation Rate
An in-place Huffman code length calculation demonstration from Alistair Moffat. The abstract of that paper may be fetched from this location.
An Algorithm for Online Data Compression Rate
The code from an article from by Sergey Ignatchenko from the October 1998 C User’s Journal. (see ignatch.zip)
Text compression for embedded controllers Rate Some simple BASIC routines to compress data without extravagant data or code space. The author seems to indicate this isn’t Huffman coding, but doesn’t say what it is.
Huffman Coding Class Rate This version of file encoder and decoder program is based on the Huffman coding method. It explicitly demonstrates the details of the files during the encoding and decoding. The algorithm is encapsulated in a class En_Decode in standard C++.
Compression and Encryption Sources Rate Links to a variety of lossless coders, includes source for Huffman, arithmetic, LZSS, and other compressors.
McKee’s Directed Acyclic Graph Compression Rate Will McKee has released this as freeware – includes complete source to a string substitution compressor. From the description it sounds as though it’s variant on LZSS, but I’ll defer to anyone willing to do a real analysis.
Johan Wahlin’s Huffman Tool Rate A Java program that prints javacode for coding and decoding the characters through a Huffman tree.
Improved Huffman coding using recursive splitting. Rate This page contains a paper that describes a program that attempts to improve on Huffman compression by manipulation of the data stream.
The Huffman Compression Algorithm Rate Yet another description of Huffman coding. Comes with a couple of lovely diagrams and some Delphi code.
bwtzip: A Linear-Time Portable Research-Grade Universal Data Compressor Rate bwtzip is an ongoing project, distributed under the GNU General Public License, to implement a Burrows-Wheeler compressor in standard, portable C++. It is research-grade in that it is highly modularized and abstracted, so that it is simple to swap out parts of the compressor without affecting anything else. This makes it easy to experiment with different algorithms at different stages of compression.
Looks like Steven T. Lavavej released a new version of bwtzip in early February, 2003. A wide variety of improvements, most of them in implementation – not visible to the end user. A description of recent changes is found here
Tutorials, Reference, Presentations

Huffman Coding with Priority Queues This article is really about using the priority queue containers that are part of the standard C++ library. The example program implements a Huffman Encoder using the queues, showing how they can do a fairly complex piece of work without too much coding on your part.
David’s Compression Page This page has a some Huffman compression code that has been adapted to implement a unique property that author refers to as one to one compression. In a nutshell, this property means that for any file X, F( F'( X ) ) == X. (F is either the compressor or decompressor, and F’ is its opposite number.)This is definitely not the case for most conventional compression algorithms.
One to One Compression This site discusses a characteristic of some compression algorithms that the author refers to as One to One compression. In a nutshell, this property means that for any file X, F( F'( X ) ) == X. (F is either the compressor or decompressor, and F’ is its opposite number.) This is definitely not the case for most conventional compression algorithms.
Michael Dipperstein’s Huffman Code Page Michael Dipperstein describes his personal quest for understanding an implementation of Huffman coding. Full source included.
The page was updated with new source December, 2002.
Static Huffman Coding Arturo Campos describes one of the simplest yet often effective compression algorithms. Believe it or not, Huffman coding with an order-0 model is nearly 50 years old!
When Fibbonaci and Huffman Met Arturo Campos describes the circumstances that lead to a Huffman tree with the worst possible code lengths.
Canonical Huffman Coding Arturo Campos descrives Canonical Huffman Coding, the technique used in the deflate algorithm made popular by PKZip. This type of Huffman coding follows some specific rules regarding the structure of the Huffman tree that simplify the process of transmitting the tree.
Data Compression – Static Defined-Word Schemes Rate
A very nice description of Huffman coding, as well as a few other types of coding. I believe this is part of a survey paper by Debra A. Lelewer and Daniel S. Hirschberg.
Shannon Fano Coding Rate
An overview of Shannon Fano coding from the folks at the DataCompression Reference Center. This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Video and Audio Compression Rate
Class notes on lossless compression algorithms. Quick info on Huffman, Adaptive Huffman, and LZW.
The Lossless Compression (Squeeze) Page Rate
This page is designed made to teach people about Lossless compression algorithms through the use of text graphics and Java Applets! Dominik Szopa has created pages that demonstrate Huffman, Adaptive Huffman, and LZW compression.
DCL reader SF has this to say: While the site itself is rather quick, it’s disorganized…the Java applets really don’t show what’s going on at all. They show only the external effects…This site has definate potential, and I do recommend people see it. However, it’s also got a ways to go yet. .
Practical Huffman Coding Rate
A page by Michael Schindler that describes Huffman coding in a fair amount of detail. Also includes links to other information resources. This page also has an explanation of the canonical huffman table storage algorithm.
Data Compression Algorithms Rate
by Jeffrey N. Ladino. His description of the page: This page is a research project in the field of data compression algorithms. It is intended to be an informative overview for a beginner in the field of computer science. Mostly talks about lossless compression, with an explanation of Huffman coding.
Huffman Coding Rate
The Data Compression Reference Center talks about Huffman coding. A short but fairly succint explanation. This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Huffman Compression Rate
A straightforward discussion of Huffman compression. Written at a level so that it can be understood without much experience in data compression or programming.
Lossless Compression Algorithms (Entropy Encoding) Rate
An overview of the basics, including Shannon-Fano, Huffman, Arithmetic coding, and a section on LZW for good measure.
Shannon-Fano Coding Rate
The definition from the NIST Dictionary of Algorithms and Data Structures.
EGI compression schemes Rate
This page discusses the various compression schemes used by EGI, Shannon-Fano, BWT, and RLE. EGI is a player of animation sequences.
Self-similar Huffman Trees with Extreme Guessing Propertie Rate An article by John Pliam. Needs a better summary, but I don’t quite get it, other than the fact that there is some cryptographic thinking going on here.
K-ary Huffman Encoding Rate The definition from the NIST Dictionary of Algorithms and Data Structures.
Huffman Coding: A CS2 Assignment Rate Some good introductory explanation here.
Wikipedia Entry: Huffman Coding Rate The Wikipedia entry for Huffman Coding. A fairly terse definition.
The Huffman Compression Algorithm Rate Yet another description of Huffman coding. Comes with a couple of lovely diagrams and some Delphi code.
bwtzip: A Linear-Time Portable Research-Grade Universal Data Compressor Rate bwtzip is an ongoing project, distributed under the GNU General Public License, to implement a Burrows-Wheeler compressor in standard, portable C++. It is research-grade in that it is highly modularized and abstracted, so that it is simple to swap out parts of the compressor without affecting anything else. This makes it easy to experiment with different algorithms at different stages of compression.
Looks like Steven T. Lavavej released a new version of bwtzip in early February, 2003. A wide variety of improvements, most of them in implementation – not visible to the end user. A description of recent changes is found here
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Image Compression

Compression that is specifically oriented towards still images is given here. Note that the more specialized compression algorithms such as JPEG and JBIG have their own sections, this tends to collect everything else.
[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Books

Image and Video Compression Standards Algorithms and Architectures, Second Edition Rate
by Vasudev Bhaskaran, Kluwer Academic Publishers, Boston Hardbound, ISBN 0-7923-9952-8, 472 pp., $97.50. This book describes the various standards in use today, including MPEG, JPEG, H.261, and so on.
Please use the link on this page to purchase the book through Amazon.com. Your purchase will help support this web site.
Managing Gigabytes, 2nd Edition – Witten, Moffat, and Bell Rate
The second edition of Managing Gigabytes: Compressing and Indexing Documents and Images by Ian H. Witten, Alistair Moffat, and Timothy C. Bell, is now available (May 1999), published by Morgan Kaufmann Publishing, San Francisco, ISBN 1-55860-570-3.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Sample pages on DCT Rate
Sample pages on line from the book Discrete Cosine Transform: Algorithms, Advantages, Applications by Kamisetty Ramamohan Rao, P. Yip. The first 6 pages of the book are excerpted here, giving a complete history of the DCT.
Compressed Image File Formats: JPEG, PNG, GIF, XBM, BMP by John Miano Rate
“Compressed Image File Formats is an appealingly compact and useful guide to some of today’s most popular file formats used for image data. For any programmer who needs to know how images are stored, this concise reference can serve as a really invaluable resource.”
Note that the source code for this book includes an independent implementation of a PNG codec, which may be one of a kind. Link to the source code on this page.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Bilddatenkompression/Image Data Compression Rate
Subtitled Basics, Standards and Wavelet-Based Algorithms for Image and Video Coding. This German-language textbook contains full source code (ANSI-C) of a wavelet-based image coder.
Image Compression Algorithms Rate
The book that accompanies the course of the same name. Russian-language submitter reports that the book has info on RLE, LZW, CCITT Group 3, Jpeg, Wavelet, and Fractal compression.
Digital Image Compression Techniques (Tutorial Texts in Optical Engineering, Vol 7) Rate by Majid Rabbani and Paul W. Jones. This book shows up in at least one bibiblography, I would appreciate reviews from a reader.
Digital Compression for Multimedia: Principles & Standards Rate Jerry Gibson, Toby Berger, Tom Lookabaugh, Rich Baker and David Lindberg. Drawing on their experience in industry, research, and academia, this powerful author team combines their expertise to provide an accessible guide to data compression standards and techniques and their applications
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Commercial Libraries

RICAZip.com Rate
RICAZip.com has proprietary lossless image compression technology called RICA (Reversible Image Compression Algorithm). RICA retains original file formats (e.g. TIFF, DICOM, BMP, TGA, PGM etc.). RICACom says We have yet to find any method that provides better compression ratios (for truly lossless), including wavelet. On a PII 450MHz RICA compresses @ 6MB per second and decompresses at 12MB per second.
Available as a standalone image archive app, Adobe Photoshop Plugin, Browser Plugin, and RICA SDK.
DCL reader Karen H. says: Evaluation of this product demonstates excellent compression ratios and it is also very fast compared to other methods I have used.
BitJazz Rate
A company that makes PhotoJazz, a lossless compression plug in package that they describe as having Breakthrough lossless photo-quality compression of stills and movies for archival, print, and the Internet. Version 2.0 supports Mac and Windows, Photoshop, QuickTime, and Quark. You can download the Reader for free and try it out.
ImageGear Rate ImageGear from Accusoft is a super-capable imaging library, available in four different varieties. It supports the normal roster of file types, but also includes some more advanced image and file formats, such as PDF and JPEG-2000.
Version 13 is shipping as of October, 2003.
Intel Integrated Performance Primitives Rate Intel has created a new library designed to deal with varous primitives used in Data Compression. Intel says: Intel® Integrated Performance Primitives (IPP) is a software library which provides a range of library functions for multimedia, audio codecs, video codecs (for example H.263, MPEG-4), image processing (JPEG), signal processing, speech compression (i.e. G.723, GSM ARM*) plus computer vision as well as math support routines for such processing capabilities.Unlike their previous libraries, this is now a commercial product which is going to cost you as much as $199. Works with Windows and Linux.
The GSLib image compression library Rate Alexander Simakov has created a streaming, DCT-based, lossy compression library that works on gray scale images. This is a shareware library that works with Win32 programs. Registered users get source code, samples in several languages, and help files in English and Russian.
ImagXpress Standard Rate This imaging library from PegasusImaging supports reading and writing of a wide variety of compressed image formats, including JPEG, GIF, and PNG. JPEG2000 and Lossless JPEG are advertised as available with add-on packages.
PDF Creator Pilot Rate This library is able to product PDF documents from VB, Delphi, and Visual C++. This naturally includes the ability to create compressed images using jpeg, zlib, and CCITT formats.
LuraWave OCX-SDK Rate The LuraWave OCX is an OLE-Control ready to be integrated into numerous development environments such as MS Visual C++, MS Visual Basic, Borland Delphi, and several of the MS Office components. This product allows you to easily load and decompress Lurawave images, as well as converting to/from TIFF and BMP formats. A demo version is available which limits you to 640×480 pixels.
Commercial Programs

Where can I get image compression programs? Rate
The comp.compression FAQ attempts to answer this question.
Blaze MediaConvert Rate
This product performs a huge number of conversions among different media types. Want to convert your huge collection of MP3 files to WMA? No problem. MPEG-2 to AVI? No problem. MediaConvert even handles some unusal conversions, such as video to animated GIF. And naturally, a huge number of conversions between various image formats, including GIF, JPG, PNG, and a host of additional types.
Release 2.3 shipped in Julyy, 2003.
MrSID by LizardTech Rate
LizardTech has developed a portable image format called MrSID that is used by people who have huge files and want to render them in a nearly lossless manner. I think the idea is to render it on a given output device using just as many pixels as is absolutely necessary. Looks like they are pitching this stuff to the mapping and medical industries.
Miliki Super Compressor Professional Rate
This product is advertised as a revolutionary compression package from QuickCAT Technologies. It comes in two versions: a Pro package that compresses documents and images, and a Basic version that compresses only images.
ReaConverter Pro Rate
This nifty program performs batch conversions of programs from a wide variety of types, including JPEG, BMP, TIF, PNG, and the usual other suspects. Lots of other features are added to the mix, including such goodies as watermark insertion, cropping, sharpening, blurring, etc.
Version 3.0 shipped in April, 2003.
RICAZip.com Rate
RICAZip.com has proprietary lossless image compression technology called RICA (Reversible Image Compression Algorithm). RICA retains original file formats (e.g. TIFF, DICOM, BMP, TGA, PGM etc.). RICACom says We have yet to find any method that provides better compression ratios (for truly lossless), including wavelet. On a PII 450MHz RICA compresses @ 6MB per second and decompresses at 12MB per second.
Available as a standalone image archive app, Adobe Photoshop Plugin, Browser Plugin, and RICA SDK.
DCL reader Karen H. says: Evaluation of this product demonstates excellent compression ratios and it is also very fast compared to other methods I have used.
DAX source code Rate
This code is reputedly good for compressing B/W images. The web site refers to it as Difference Adaptive compression. It’s patented.
MyPhotoZip Rate
These guys are claiming a quantum leap in image compression! It looks like you can get a 30 day free trial of this product. The affiliate marketing program for MyPhotoZip is kind of goofy, see more about it at ecomecom.net.
Visitor Tim A had this to say: A demo of MyPhotoZip is available on CNET, ZDNet (possibly others). My first impression is that it’s very similar to JP2. Lossless compression performance is virtually identical on a few test images. Nothing special to talk about :(
Donald J. was a bit more enthusiastic: I have run several tests on this product and the quality compared to JPEG is far superior. For a raw TIFF image of 10 MB or more the file size can be compressed as much as 1000 to 1 while still maintaining decent quality if you adjust the color portion to a higher number.
Power Compressor Rate Image Power makes this product which compresses documents using JBIG, GIF, and JPEG2000 encoders. This product is supposed to help you with web publishing, archiving, and image management.
ACDZip Rate ACDZip is a zipping and unzipping program that gives you the power to compress image, audio, video and document files. It includes fast image previews and is ideal for opening zip files, backing up files, saving hard disk space, preparing files for distribution and protecting them with encryption and passwords.
AutoImager Rate Full-featured batch image processing and conversion software. Over 70 image formats are supported, and the software provides an extensive array of image enhancement, editing, and processing operations. All processing and conversion operations have numerous options that can be optionally set for maximum control. The entire application is highly customizable. AutoImager also offers complete command-line support. With over 130 configurable command-line choices, it’s easy to create batch files to perform image processing tasks which may need to be done routinely. A list of available features far too long to list here.
MediaZip Rate MediaZip is a Windows program that performs lossless compression/decompression and manages archives of media files (Sound and Picture). Welcome to the MediaZip home page.
Zip-I-Mage Rate This archiver is built specifically for support of image archiving. Supports popular formats such as JPG and BMP.
BMPSqueezer Rate An interesting program that takes an image and squeezes it down into a Java applet. Shareware, so you can give it a spin for free.
ReaCompressor Rate ReaCompressor is an image compression tool that is designed to assist you in preparing images for the web, emailing, etc. It lets you choose from various formats: JPEG, PNG, GIF, and TIFF, and shows you the results of the compression on screen.
Version 1.8 shipped in October, 2003, and added support for JPG region specific compression and over 340 input formats.
http://www.barrt.ru/parshukov/imcomp.htm Rate A shareware image compression program that supports a ton of different formats.
Companies/Organizations

Pegasus Imaging Corporation Rate
Pegasus Imaging Corporation has their fingers in many different pies, mostly related to imaging and image compression. This home page has links to many of their diffferent products, a variety of programs and libraries.
RICAZip.com Rate
RICAZip.com has proprietary lossless image compression technology called RICA (Reversible Image Compression Algorithm). RICA retains original file formats (e.g. TIFF, DICOM, BMP, TGA, PGM etc.). RICACom says We have yet to find any method that provides better compression ratios (for truly lossless), including wavelet. On a PII 450MHz RICA compresses @ 6MB per second and decompresses at 12MB per second.
Available as a standalone image archive app, Adobe Photoshop Plugin, Browser Plugin, and RICA SDK.
DCL reader Karen H. says: Evaluation of this product demonstates excellent compression ratios and it is also very fast compared to other methods I have used.
Tak’Asic Rate
Tak’Asic provides Lossless/Lossy still image compression/decompression ICs solution.
. Our ICs support JBIG, MH, MR, MMR and JPEG standards.
Our latest product, Tak’B3, is the world fastest JBIG codec available. It is able to process images at 133Mpixel/sec minimum and up to 2128Mpixel/sec. It also provides code conversion (MR/MR/MMR <-> JBIG) and scaling functionality.
KT-Tech Incorporated Rate KT-Tech seems to be active in various compression areas, developing their own algorithms rather than implementing standards. Their web site has demos of their latest still image and video technologies. One interesting product is software to improve the performance of other encoders, such as those used by Microsoft’s Windows Media codecs.
Update: the web site now offers online demos of sound compression as well!
DAKX LLC Home Page Rate DAKX is claiming a new method of lossless data compression that is fast and patented. It works on audio and video data. The method is called difference-adaptive compression. DAKX supplies a bit of source code that you can experiment with, and will be happy to license the technology to you or your company.
Accusoft Rate Accusoft makes a variety of imaging products, including a nice commercial imaging library.
FMA&H Rate This page is a mystery to me.
LEAD Technologies, Inc. Rate These guys are big in the world of software that does image processing. What does this have to do with data compression? Well, they do have products that render, convert, and create compressed formats such as JPEG, TIFF, and GIF.
IBM Research – Image application solutions Rate The image application group at IBM’s Watson Research Center works on quite a few different topics related to digital imaging, including image capture, color science, printing and displaying images, and so on. Of course, part of that is image compression, which is why we’re interested in them.
Courses/Seminars

Multimedia Computing and Networking 2002 Rate The term “Multimedia” obviously covers a lot of different topics. Compression is one of them, and there is certainly a great deal to learn about compression and media formats at this conference.
TSBK01 Image Coding and Data Compression Rate A course being given by the Image Coding Group at Linköping University. Contains a few useful links plus some course material.
Files

The USC-SIPI Image Database Rate
The USC-SIPI image database is a collection of digitized images. It is maintained primarily to support research in image processing, image analysis, and machine vision. Contains copies of the mystical goddess Lenna.
CCITT standard fax images Rate
TIFF versions of the CCITT images.
Waterloo BragZone test suite Rate
In the BragZone you will find the following:
A suite of test images, the “Waterloo Repertoire”.
Rate-Distortion plots for various compression codecs.
The data from which the above plots are derived.
Sample images at selected compression ratios.
Image set used in ACT Rate
A SET of 23 images totalling 27,133,146 bytes. The file type is RAS, does that mean that the files are a simple raster dump? I’m not sure. These files are listed in a few different places as being used in benchmarks.
CCITT standard images (Bilevel) Rate Images commonly used in compression tests are stored here in Sun raster format. At this time I believe that all you will find here are gray scale images.
Computer Vision Test Images Rate A list of links to test images. Utopia for the benchmark junkie.
Compression Technology in Multimedia Rate Lots of information on this site concerning compression of still pictures, moving pictures, and audio. Much of the site is devoted to comparisons of a few different algorithms. A report section draws a few conclusions about the whole thing.
Standard Test Images and Sequences Rate This site has links to a few standard test images and sequences, including 512×512 8 bit images, and a good selection of QCIF sequences.
Image & Video Quality Assessment at LIVE Rate The folks at LIVE conducted a subjective test of images at various compression levels, and have made the results available here. The images and results are both available here.
Google – Compression Test Images Rate Google’s directory entry point for test images used in data compression.
Finnish

Yleisimpiä kuvanpakkausmenetelmiä ja niiden vertailua Rate
This appears to be an overview of various data compression methods applied to image compression, both lossy and lossless. The page is entirely in what appears to be Finnish.
French

Compression des images (et autres documents) Rate
This site has pointers to various sits related to image compression. The entire site is written in French.
German

Bilddatenkompression/Image Data Compression Rate
Subtitled Basics, Standards and Wavelet-Based Algorithms for Image and Video Coding. This German-language textbook contains full source code (ANSI-C) of a wavelet-based image coder.
Hardware

Tak’Asic Rate
Tak’Asic provides Lossless/Lossy still image compression/decompression ICs solution.
. Our ICs support JBIG, MH, MR, MMR and JPEG standards.
Our latest product, Tak’B3, is the world fastest JBIG codec available. It is able to process images at 133Mpixel/sec minimum and up to 2128Mpixel/sec. It also provides code conversion (MR/MR/MMR <-> JBIG) and scaling functionality.
Links

The Art Of Lossless Data Compression Rate
A comprehensive set of tests on lossless data compression.
Image Compression with Set Partitioning in Hierarchical Trees Rate
Welcome to the WWW home page that describes Set Partitioning in Hierarchical Trees (SPIHT): the powerful new wavelet-based image compression method.
Vladimir Valenta’s Home Page Rate
Vladimir has pointers to a batch of his papers here, which seem to concentrate on image compression, including VQ and Wavelet based compression. Plus many links to image compression, fractal, and wavelet pages.
Compression des images (et autres documents) Rate
This site has pointers to various sits related to image compression. The entire site is written in French.
David Clunie’s Medical Image Format Site Rate
David Clunie is the chair of the DICOM standards committee, and has a wealth of links on this page to information related to medical imaging.
Compression with Reversible Embedded Wavelets Rate CREW is a compression algorithm developed by RICOH that has been offered up to the JPEG working group as a potential standard. This page contains a description of the algorithms, along with samples and related documents.
Binary Tree Predictive Coding Rate John Robinson’s page on BTPC, which includes documentation, samples, links, and source. BTPC is designed to do both lossy and lossless compression of images.
John updated this package to version 5 in March, 2003.
Avideh Zakhor’s Home Page Rate Avideh Zakhor has links to many of her papers on image compression.
Image Compression Research Rate A page devoted to image compression research at the University of Joensuu, which would appear to be in Finland. Links to more research and a PhD thesis.
Medical Image Format FAQ – Part 7 Rate Lots of pointers here. Relevant to compression because of the wealth of pointers to various formats used in medical imaging, such as JPEG-LS and Lossless JPEG.
3DCompression.com Rate A directory of links and resources on compressing the 3D models used for computer graphics and other large geometric datasets. This is a replacement for the site at http://www.cc.gatech.edu/~kingd/3Dcompression.html.
The DICOM Standard Rate This page gives a short introduction to the DICOM standard, commonly used for medical imaging. It has a lengthy set of links to DICOM viewers, images, and other resources.
Compression Research Rate This page contains information and links which are small a sampling of compression research that has been performed using the Lena image.
Newsgroup Posts

Where can I get image compression programs? Rate
The comp.compression FAQ attempts to answer this question.
Where can I find Lenna and other images? Rate
The comp.compression FAQ attempts to answer this for you.
Image compression hardware Rate
The comp.compression FAQ provides a pointer or two.
Tell me about Fast DCT (Discrete Cosine Transform) algorithms Rate
The comp.compression FAQ attempts to do just that.
Why Can’t One Image Coder Rule? Rate Alex Ng posed the question on comp.compression: “In general, you cannot have one image coder can compress well for ALL images. Why?”
This set off a lively and somewhat useful discussion, with lots of thoughtful posts from Thomas Richter and others. Always good to find some intelligent thought on the compression newsgroup.

Non-Commercial Libraries

CXImage Rate
Yet another image library! This one promises to load, save, and display BMP, JPEG, GIF, PNG, MNG, and J2K compressed images.
Version 5.9 of this library shipped in February, 2004.
Java Image Coding Rate
Java libraries to read various image formats, including many which are compressed. Hence its appearance here.
QccPack — Quantization, Compression, and Coding Library Rate
James E. Fowler at Mississippi State University has created this library, which is an open source collection of routines that are useful for people interested in data compression research. The distribution includes QccSPIHT.
Version 0.45 is available as of December, 2003.
DjVu – Next generation image compression technology Rate
DjVu is an image compression technique that is meant to be used on scanned documents. AT&T has created a browser plugin that supports DjVu files. AT&T claims that DjVu files are 5 to 8 times smaller than GIF or JPEG images of similar quality. Some public source code is provided here, but the exciting parts of DjVu are not available.
Update: I believe this project has morphed away from AT&T and into the Open Source World. The AT&T site has been gone since 6/2002, I hope that this represents its new incarnation. I’m also moving the project status from Commercial to Non-Commercial
IMAGELIB from Colosseum Builders, Inc – V 4.0 Rate
Due to the overwhelming number of requests for JPEG code that works with Borland C++Builder we have put out an Alpha version of the Colosseum Builders’ Image Library for C++. The latest version includes encoders and decoders for JPEG, GIF, Windows BMP, XBM, and PNG. It also includes an interface to VCL so that these image formats can be used at design-time with C++Builder. The current version now works with MSVC++.
TIFF Software Rate
A library that supports reading and writing of TIFF files.
Dali Rate Dali is a project at Cornell that aims to create a programming environment dedicated to the manipulation of video, audio, and image data. Naturally, this includes multiple codecs for various data types.
Imagero Rate A Java library that can read a few different image file types. Currently that includes BMP, some TIFF, PNG, JPEG, and more, along with metadata from a few different file types,
Version 1.30 is shipping as of January, 2004
OpenTiff Rate OpenTiff is an object-oriented interface to TIFF formated image files. Unlike other Tiff toolkits, it allows an arbitrary set of tags to be defined and used in a Tiff file.
An Image Decoder Based on IImgCtx Rate This article shows how to decode images with IImgCtx interface provided by IE. In addition to the image types decoded with the IPictur einterface, IImgCtx also decodes TIFF and PNG.
JXPM – XPM processing library for Personal Java Rate This library lets you read XMP image files using Personal Java – a defunct standard targeted at handhelds and other slighly constrained platforms.
Animal – AN IMAging Library Rate Yet another imaging library that claims to support over 80 image formats under Win32. This is listed as an Alpha status project that is shipping version 0.14.0 as of July, 2004.
FreeImage Rate FreeImage is yet another free library for image reading, writing, and manipulation. FreeImage supports a long list of compressed formats, including JPEG, PNG, TIFF, and more. Claims to support multiple platforms, but it does apear that most of the experience with this project is on Win32 systems.
Version 3.4.0 is shipping in July, 2004.
JIU – The Java Imaging Utilities – An image processing library Rate JIU, the Java Imaging Utilities, is a library which offers functionality to load, analyze, process and save pixel images. It is written in Java and comes with full source code under the GNU General Public License (GPL) version 2.
dcm4che – DICOM in Java Rate This open source project is an implementatoin of DICOM in Java. DICOM refers to the Digital Imaging and Communications in Medicine standard, which provides standards for moving pictures around in medical applications.
Netpbm Rate Netpbm is a C package of routines for conversion, rendering, and manipulation of graphics files. The program understands a wide array of image formats, and best of all, is completely free.
The 10.22 release shipped in May of 2004.
ImageMagick Rate ImageMagick is a robust collection of tools and libraries offered under a free license to read, write, and manipulate an image in many image formats (over 87 major formats) including popular formats like TIFF, JPEG, PNG, PDF, PhotoCD, and GIF. Programming interfaces are provided for C/C++, Java, Perl, VB, and more.
Version 6.0.3 is shipping in July, 2004.
FreeImage Rate The Free, Quality Image library for Windows. This library decodes quite a number of image formats, but don’t expect to see GIF in there anytime soon. Perhaps after the patent expires…
GraphicsMagick Image Processing System Rate GraphicsMagic is a branch off of the ImageMagick project. I suppose there are some interesting political machinations behind all that, but for right now you should just know that GraphicsMagick is attempting to provide a stable set of code that can be used in other free and proprietary products. This consists of a big batch of image processing library functions, as well as a command line tool that lets you easily exercise some of those functions.
Version 1.1.2 shipped in June, 2004.
DevIL – A full featured cross-platform image library Rate DevIL provides the code needed to load a wide variety of images into your program. A nice long list of images that can be loaded are listed here, and a smaller but still quite nice list of formats that can be written to. Displaying images is currently supported under OpenGL, Windows GDI, SDL, DirectX, and Allegro,
Version 1.6.7 shipped in June, 2004.
DjVuLibre Rate This is an open-source package of DjVu programs and libraries, including encoders, viewers, browser plugins, and various utlities. The DjVu standard for document encoding was once an ATT research project, but now has been commercialized by LizardTech. This project is an attempt to popularize and evangelize the DjVu technology, with at least the benign awareness of LizardTech.
Release 3.5.13 shipped in April of 2004.
In Memory Image Compression Rate This article by Amer Gerzic uses GDI+ to load an image, then compresses it into memory. In the sample code he loads a BMP file and converts it to an in-memory JPEG file.
Java and Windows Pdf Extraction Decoding Access Library Rate A Java library released under the LGPL license for extracting text and images from pdf files, with full source code and examples. It also provides a rasterizer.
A commercial product called WinPedal is also available. WinPedal is an EXE that has grouping functionality that converts PDF text into XML.
Non-Commercial Programs

VcDemo – Image and Video Compression Learning Tool VcDemo is an interactive image and video compression (freeware) software package for Windows. It is intended as a tool for learning about compression techniques: from basic sampling and PCM to today’s most advanced scalable embedded zerotree wavelet image compression technique and the MPEG video compression standard. VcDemo is an ideal tool for students to explore the possibilities of compression theory using textbook algorithms on real images. The package is also very suitable for on-line demonstrations in lectures. A user manual is available, as well as a set of exercises that can serve as home work.
BMF Rate
BMF program is lossless/near-lossless image compression utility. It supports true colour, high colour, greyscale and paletted images compression.
Where can I get image compression programs? Rate
The comp.compression FAQ attempts to answer this question.
MG Pages Rate
Some pages that go along with the book “Managing Gigabytes”, by Witten et.al. These pages are devoted to MG, “an open-source indexing and retrieval system for text, images, and textual images.”
(X)MedCon – Medical Image Conversion Utility Rate
A free program to deal with image formats in popular medical formats, including DICOM, SPM, PNG, and GIF.
Version 0.9.1 of (X)MedCon shipped in January, 2004.
DjVu – Next generation image compression technology Rate
DjVu is an image compression technique that is meant to be used on scanned documents. AT&T has created a browser plugin that supports DjVu files. AT&T claims that DjVu files are 5 to 8 times smaller than GIF or JPEG images of similar quality. Some public source code is provided here, but the exciting parts of DjVu are not available.
Update: I believe this project has morphed away from AT&T and into the Open Source World. The AT&T site has been gone since 6/2002, I hope that this represents its new incarnation. I’m also moving the project status from Commercial to Non-Commercial
Image Compression Using Huffman Coding Rate
Tim’s Home Page has three different programs that attempt to compress images using Huffman coding.
Bernie’s TMW0.51 Page Rate
TMW is a program for losslessly compressing greyscale images that gives world class compression ratios, at the cost of being tremendously CPU intensive. The current version is TMW_0.51, and is still completely experimental.
Advanced Image Coding Rate Advanced Image Coding (AIC) is an experimental still image compression system that combines algorithms from the H.264 and JPEG standards. More specifically, it combines intra frame block prediction from H.264 with a JPEG-style discrete cosine transform, followed by context adaptive binary arithmetic coding as used in H.264. The result is a compression scheme that performs much better than JPEG and close to JPEG-2000.
The Glicbawls page Rate Glicbawls is a lossless and/or near-lossless image compression algorithm that apparently does really well on gray-scale images but perhaps not as well on color. This link points to an archived page, as the original has disappeared from the net. As a result, links on the page may or may not work propery
pbmplus – image file format conversion package Rate Pbmplus is a toolkit for converting various image formats to and from portable formats, and therefore to and from each other. The idea is, if you want to convert among N image formats, you only need 2*N conversion filters, instead of the N^2 you would need if you wrote each one separately.
This software isn’t necessarily related to image compression, but it is often quite useful when working with images.

Epic24 Rate From the site: Epic24 is a GUI program that I wrote to interactively compare graphic compression codecs against each other. It currently contains JPG, Lossless JPG, JPEG 2000, (Jasper Library Implementation), PNG, John Robinson’s BTP and ATP, and finally my own lossless graphics compression called IMPLODE (IMage Predictive LOssless Decoder Encoder).
APT Rate APT (Adaptive Prediction Trees) image coding supersedes BTPC (Binary Tree Predictive Coding). It is a general-purpose compression scheme for all types of still image. It does both lossless and lossy compression of monochrome and color images from 1 to 16 bits per component. Its performance on all image types is often close to that of the best alternative.
Binary Tree Predictive Coding Rate John Robinson’s page on BTPC, which includes documentation, samples, links, and source. BTPC is designed to do both lossy and lossless compression of images.
John updated this package to version 5 in March, 2003.
Eri32 High Performance Freeware Multimedia Archiver Rate This web page shows a set of images that the author uses to demonstrate the performance of the Eri compressor. The claim is that Eri32 does better on these 24 bit color images than any other lossless compressor.
Scilab Image Processing Toolbox Rate SIP intends to do imaging tasks such as filtering, blurring, edge detection, thresholding, histogram manipulation, segmentation, mathematical morphology, color image processing, etc. These operations are useful for problem solving in real-world applications ranging from car motion planning to automatic diagnosis of medical images.
Version 0.3.1 is shipping as of May, 2004.
imgtops Rate This open source Linux project converts image files (JPEG, GIF, PNG, etc.) to Encapsulated PostScript, in what is supposed to be an efficient manner.
kdc2tiff Rate Software to convert the proprietary KDC files produced by Kodak digital cameras into JPEG or TIFF format. Appears to work under Linux only.
iRad: DICOM viewer for OS X Rate iRad is an open source project written to view DICOM files on your Mac systems running OS X. For those of you not in the know, DICOM is a set of standards for storing and accessing medical imagery. It is written to help with the unique requirements that the medical industry has for imaging.
Version 1.4 is shipping in a beta version in May, 2003.
ImageMagick Rate ImageMagick is a robust collection of tools and libraries offered under a free license to read, write, and manipulate an image in many image formats (over 87 major formats) including popular formats like TIFF, JPEG, PNG, PDF, PhotoCD, and GIF. Programming interfaces are provided for C/C++, Java, Perl, VB, and more.
Version 6.0.3 is shipping in July, 2004.
GraphicsMagick Image Processing System Rate GraphicsMagic is a branch off of the ImageMagick project. I suppose there are some interesting political machinations behind all that, but for right now you should just know that GraphicsMagick is attempting to provide a stable set of code that can be used in other free and proprietary products. This consists of a big batch of image processing library functions, as well as a command line tool that lets you easily exercise some of those functions.
Version 1.1.2 shipped in June, 2004.
DjVuLibre Rate This is an open-source package of DjVu programs and libraries, including encoders, viewers, browser plugins, and various utlities. The DjVu standard for document encoding was once an ATT research project, but now has been commercialized by LizardTech. This project is an attempt to popularize and evangelize the DjVu technology, with at least the benign awareness of LizardTech.
Release 3.5.13 shipped in April of 2004.
Papers/Documentation

Image Compression – from DCT to Wavelets : A Review Rate
by Subhasis Saha. A survey paper on various techniques of image compression.
Woontack Woo – Publications Rate
Woontack Woo has published quite a few papers dealing with coding and compression of stereo images. This is one of the few places you can find information on this somewhat esoteric subject.
Image Compression using Backprop Rate
From the site: Computer images are extremely data intensive and hence require large amounts of memory for storage. As a result, the transmission of an image from one machine to another can be very time consuming. By using data compression techniques, it is possible to remove some of the redundant information contained in images, requiring less storage space and less time to transmit. Neural nets can be used for the purpose of image compression, as shown in the following demonstration.
NASA Vision Group Publications Rate
A big batch of image compression papers are on line here. I guess the entire contents of all the papers is online thanks to the contributions of the US government. For image compression, this is a fantastic resource.
Jeff Vitter’s Recent Papers Rate
Jeff Vitter is a publishing machine. A substantial subset of is work deals with data compression and/or information theory. On top of all that, he’s good enough to keep most of his work online in ps and pdf format.
Stuart Inglis Rate
Home page for Stuart Inglis, maintainer of the Compression Links page. Stu’s thesis is online, along with the source code used during his study. Stuart says that it achieves the world’s best image compression!
Digital Image Compression Rate
An article by Giovanni Motta and friends that appears in the Encyclopedia of Computer Science. Packs a lot of information into a short 8 or so pages.
Reader sreenu says: excellent article.
Vladimir Valenta’s Home Page Rate
Vladimir has pointers to a batch of his papers here, which seem to concentrate on image compression, including VQ and Wavelet based compression. Plus many links to image compression, fractal, and wavelet pages.
EPIC (Efficient Pyramid Image Coder) Rate
EPIC is a lossy image compression program. It uses subband decomposition followed by an entropy encoder to get its job done. This page has links to the code, papers, references, and more.
Robert Estes Rate
Robert Estes (UCDavis – image compression research). Robert has pointers to many of his papers on this page. He has info on Wavelet-based image compression, image compression, plus some peripherally related topics such as image quality.
Efficient Quadtree Code: Spatial Linear Quadtree Rate
Laurent Balmelli from the neutral country of Switzerland has some C++ code to do some interesting quadtree processing. He would like you register if you are going to use the code, but this is not mandatory. This code is being used by over 100 registered users, and has at least been accessed by as many as 2500 others.
Yleisimpiä kuvanpakkausmenetelmiä ja niiden vertailua Rate
This appears to be an overview of various data compression methods applied to image compression, both lossy and lossless. The page is entirely in what appears to be Finnish.
DjVu Technical Papers Rate This page has a number of papers related to the DjVu compression format. Papers are all posted in ps.gz and DjVu formats. Note that you’ll need the DjVu plugin to read them in that format.
Lossless Compression of Continuous-Tone Images via Context Selection, Quantization, and Modeling Rate by Xiaolin Wu, University of Western Ontario. A paper on high performance lossless image compression. I’m not sure if this paper was a predecessor to CALIC/JPEG-LS or not.
Real-Time Imaging Rate An academic journal focusing on imaging and compression. It appears that all the papers published in this journal are available on line in PDF format!
Compression with Reversible Embedded Wavelets Rate CREW is a compression algorithm developed by RICOH that has been offered up to the JPEG working group as a potential standard. This page contains a description of the algorithms, along with samples and related documents.
The Design and Analysis of Efficient Lossless Data Compression Systems Rate by Paul Glor Howard, Brown University, 1993. This thesis looks at statistical methods for performing data compression.
Binary Tree Predictive Coding Rate John Robinson’s page on BTPC, which includes documentation, samples, links, and source. BTPC is designed to do both lossy and lossless compression of images.
John updated this package to version 5 in March, 2003.
Graphics and Image File FTP Archives and WWW Pages Rate A collenction of links to graphics file format information.
http://www.ora.com/centers/gff/index.htm Rate The home page of the Encyclopaedia of Graphics File Formats.
Tiling and Adapative Image Compression Rate This paper appears to discuss the concept of compressing images by breaking them down into small pieces and doing some sort of optimal compression on each piece. I assume the trick here is to locate the point of diminishing returns.
Rate Scalable Color Image Compression Rate Edward J. Delp describes his wavelet-based coding system for color images using a luminance/chromanance color space.
Papers of Edward J. Delp Rate Edward J. Delp has a big batch of papers on line. This includes a big batch that deal with Image and Video compression.
Avideh Zakhor’s Home Page Rate Avideh Zakhor has links to many of her papers on image compression.
Stack-run Image Coding Rate First sentence of the abstract says it all: We describe a new image coding approach in which a 4-ary arithmetic coder is used to represent significant coefficient values and the lengths of zero runs between coefficients
A Two-Stage Modelling Method for Compressing Binary Images by Arithmetic Coding Rate A paper describing a compression scheme for bitonal images. Complete text of paper in compressed postscript.
Pierre Moulin’s Papers Rate Pierre Moulin has authored quite a few papers on video and image compression. Unfortunately, the full text is available for only a few papers. Perhaps you could send Pierre an email asking him to put more stuff online.
Compression Technology in Multimedia Rate Lots of information on this site concerning compression of still pictures, moving pictures, and audio. Much of the site is devoted to comparisons of a few different algorithms. A report section draws a few conclusions about the whole thing.
Publications of Pamela C. Cosman Rate A bibliography of Pamela C. Cosman’s papers, with links to many that are available on line. Many papers on wavelet-based and VQ image compression, along with a few miscellaneous others.
Lossless Compression of Grayscale Medical Images – Effectiveness of Traditional and State of the Art Approaches Rate The very long title of this PDF format paper pretty much obviates the need for any more description on my part.
Learning Random Networks for Compression of Still and Moving Images Rate A paper describing the use of neural networks to do image compression.
Parallel Lossless Image Compression Using Huffman and Arithmetic Coding Rate by P. G. Howard and J. S. Vitter. This paper shows how images can be encoded and decoded using parallel processing. Both Huffman and arithmetic coding are examined.
Error Modeling for Hierarchical Lossless Image Compression Rate by P.G> Howard and J.S. Vitter. This paper from DCC ’92 describes an improved method for error modeling in hierarchical lossless image compression.
Fast Progressive Lossless Image Compression Rate P. G. Howard and J. S. Vitter. “Fast Progressive Lossless Image Compression,” Proceedings of the 1994 IST/SPIE International Symposium on Electronic Imaging Science and Technology, San Jose, CA, February 1994. This paper describes a technique that combines the author’s previously published FELICS algorithm with the progressivity of the MLP method.
FELICS – Fast and Efficient Lossless Image Compression Rate P. G. Howard and J. S. Vitter. “Fast and Efficient Lossless Image Compression,” Proceedings of the 1993 IEEE Data Compression Conference (DCC ’93), Snowbird, UT, April 1993. The abstract describes this as a lossless compression algorithm that provides results as good as JPEG in lossless mode with five times the speed.
Image Compression – from DCT to Wavelets : A Review Rate by Subhasis Saha. A typical overview article, devoted to image compression, concentrates on JPEG and Wavelet-based methods. I don’t know where this article appeared, but it looks to be peer-reviewed quality.
An Error-Controlled Octree Data Structure for Large-Scale Visualization Rate An article in the Spring 2K issue of Crossroads, the ACM student publication.
People

Stuart Inglis Rate
Home page for Stuart Inglis, maintainer of the Compression Links page. Stu’s thesis is online, along with the source code used during his study. Stuart says that it achieves the world’s best image compression!
Results

The Art Of Lossless Data Compression Rate
A comprehensive set of tests on lossless data compression.
Epic24 Rate From the site: Epic24 is a GUI program that I wrote to interactively compare graphic compression codecs against each other. It currently contains JPG, Lossless JPG, JPEG 2000, (Jasper Library Implementation), PNG, John Robinson’s BTP and ATP, and finally my own lossless graphics compression called IMPLODE (IMage Predictive LOssless Decoder Encoder).
Image & Video Quality Assessment at LIVE Rate The folks at LIVE conducted a subjective test of images at various compression levels, and have made the results available here. The images and results are both available here.
Russian

Image Compression Algorithms Rate
The book that accompanies the course of the same name. Russian-language submitter reports that the book has info on RLE, LZW, CCITT Group 3, Jpeg, Wavelet, and Fractal compression.
The GSLib image compression library Rate Alexander Simakov has created a streaming, DCT-based, lossy compression library that works on gray scale images. This is a shareware library that works with Win32 programs. Registered users get source code, samples in several languages, and help files in English and Russian.
Source Code

CPicture – The Yovav (Horror) PictureShow Rate
Straightforward code compatible with Visual C++ and MFC for decoding and displaying JPEG, GIF, BMP, and a few other types of files.
MG Pages Rate
Some pages that go along with the book “Managing Gigabytes”, by Witten et.al. These pages are devoted to MG, “an open-source indexing and retrieval system for text, images, and textual images.”
Context-based, Adaptive, Lossless Image Coder (CALIC) (Huffman) Rate
Xiaolin Wu’s static Huffman coding version of this program. Free of charge for research and non-commercial use. A total of 1.2 MBytes in a dozen or so files.
QccPack — Quantization, Compression, and Coding Library Rate
James E. Fowler at Mississippi State University has created this library, which is an open source collection of routines that are useful for people interested in data compression research. The distribution includes QccSPIHT.
Version 0.45 is available as of December, 2003.
IMAGELIB from Colosseum Builders, Inc – V 4.0 Rate
Due to the overwhelming number of requests for JPEG code that works with Borland C++Builder we have put out an Alpha version of the Colosseum Builders’ Image Library for C++. The latest version includes encoders and decoders for JPEG, GIF, Windows BMP, XBM, and PNG. It also includes an interface to VCL so that these image formats can be used at design-time with C++Builder. The current version now works with MSVC++.
Image Compression with Set Partitioning in Hierarchical Trees Rate
Welcome to the WWW home page that describes Set Partitioning in Hierarchical Trees (SPIHT): the powerful new wavelet-based image compression method.
EPIC (Efficient Pyramid Image Coder) Rate
EPIC is a lossy image compression program. It uses subband decomposition followed by an entropy encoder to get its job done. This page has links to the code, papers, references, and more.
Quad Tree Bit Determination Rate
A program to compress images, plus a write up from author Doug Houghton. Doug says its simple and fast, and does pretty well on 24 bit color images. New release from Doug as of 3/2002
Efficient Quadtree Code: Spatial Linear Quadtree Rate
Laurent Balmelli from the neutral country of Switzerland has some C++ code to do some interesting quadtree processing. He would like you register if you are going to use the code, but this is not mandatory. This code is being used by over 100 registered users, and has at least been accessed by as many as 2500 others.
Advanced Image Coding Rate Advanced Image Coding (AIC) is an experimental still image compression system that combines algorithms from the H.264 and JPEG standards. More specifically, it combines intra frame block prediction from H.264 with a JPEG-style discrete cosine transform, followed by context adaptive binary arithmetic coding as used in H.264. The result is a compression scheme that performs much better than JPEG and close to JPEG-2000.
Cquantizer Rate This code project piece uses the octree algorithm to reduce the number of colors in a bitmap. Like most of the code project stuff, it is implemented as a class compatible with Visual C++ and MFC.
Last update of this article was September, 2003.
An Image Decoder Based on IImgCtx Rate This article shows how to decode images with IImgCtx interface provided by IE. In addition to the image types decoded with the IPictur einterface, IImgCtx also decodes TIFF and PNG.
Lossless Image Coding Using Minimum-Rate Predictors Rate This page presents the source code from the paper of the given name. The software at this time only supports eight-bit grayscale, but is free for research purposes.
Netpbm Rate Netpbm is a C package of routines for conversion, rendering, and manipulation of graphics files. The program understands a wide array of image formats, and best of all, is completely free.
The 10.22 release shipped in May of 2004.
Loading JPG & PNG resources using GDI+ Rate An article on the CodeProject detailing a user’s troubles with GDI+. In particular, he found that he was unable to load JPG or PNG files stored as resources with GDI+. This article presents a way to make it happen.
This article was updated June 17, 204.
Standards

CCITT standard fax images Rate
TIFF versions of the CCITT images.
Windows GDI Bitmap Compression Rate
A description of the format used to implement bitmap compression under Windows.
Tutorials, Reference, Presentations

VcDemo – Image and Video Compression Learning Tool VcDemo is an interactive image and video compression (freeware) software package for Windows. It is intended as a tool for learning about compression techniques: from basic sampling and PCM to today’s most advanced scalable embedded zerotree wavelet image compression technique and the MPEG video compression standard. VcDemo is an ideal tool for students to explore the possibilities of compression theory using textbook algorithms on real images. The package is also very suitable for on-line demonstrations in lectures. A user manual is available, as well as a set of exercises that can serve as home work.
Image Compression with Set Partitioning in Hierarchical Trees Rate
Welcome to the WWW home page that describes Set Partitioning in Hierarchical Trees (SPIHT): the powerful new wavelet-based image compression method.
Image Compression with Vector Quantization Rate
This is billed as an introductory article with illustrations. I haven’t seen it – it requires free registration with this game development site. If you’re interested, please check it out and send me your thoughts.
Quad Tree Bit Determination Rate
A program to compress images, plus a write up from author Doug Houghton. Doug says its simple and fast, and does pretty well on 24 bit color images. New release from Doug as of 3/2002
Advanced Image Coding Rate Advanced Image Coding (AIC) is an experimental still image compression system that combines algorithms from the H.264 and JPEG standards. More specifically, it combines intra frame block prediction from H.264 with a JPEG-style discrete cosine transform, followed by context adaptive binary arithmetic coding as used in H.264. The result is a compression scheme that performs much better than JPEG and close to JPEG-2000.
I need specs for graphics formats Rate Links found in the comp.compression FAQ that help with this question
APT Rate APT (Adaptive Prediction Trees) image coding supersedes BTPC (Binary Tree Predictive Coding). It is a general-purpose compression scheme for all types of still image. It does both lossless and lossy compression of monochrome and color images from 1 to 16 bits per component. Its performance on all image types is often close to that of the best alternative.
Binary Tree Predictive Coding Rate John Robinson’s page on BTPC, which includes documentation, samples, links, and source. BTPC is designed to do both lossy and lossless compression of images.
John updated this package to version 5 in March, 2003.
Accusoft’s Image Compression Stable Rate A list of the various types of image compression that Accusoft supports, along with a little detail on each type.
Going from a JPG/GIF/BMP File to a HBITMAP File Using Plain API Rate This article on the Codeguru site by Michael Chourdakis demonstrates how to use the Windows IPicture interface to quickly load a JPEG, GIF, or BMP file into an easy to use HBITMAP. This is of course assuming you are using C on the Win32 platform.
Colour metric Rate A good explanation on color perception. This isn’t truly a data compression topic, but it actually plays a very important role in lossy image compression schemes, so I though the library ought to have at least one or two points.
3DCompression.com Rate A directory of links and resources on compressing the 3D models used for computer graphics and other large geometric datasets. This is a replacement for the site at http://www.cc.gatech.edu/~kingd/3Dcompression.html.
The DICOM Standard Rate This page gives a short introduction to the DICOM standard, commonly used for medical imaging. It has a lengthy set of links to DICOM viewers, images, and other resources.
The Golomb/Rice Image Compression Web Page Rate A senior project whose goal was to design a hardware compressor for continuous tone images. Contains a description of the algorithm, Matlab implementations, chip designs, and more.
Technical Overview of Cartesian Perceptual Compression Rate This is a bi-level image compression scheme designed to be used for scanned images of books, faxes, etc. It is a non-degrading scheme, but not lossless. The company reports that their current customer list includes GetThePatent.com, FIS|Online, JSTOR, and Kurzweil. More information about clients and partners can be found here.
Image Compression – from DCT to Wavelets : A Review Rate by Subhasis Saha. A typical overview article, devoted to image compression, concentrates on JPEG and Wavelet-based methods. I don’t know where this article appeared, but it looks to be peer-reviewed quality.
Loading JPG & PNG resources using GDI+ Rate An article on the CodeProject detailing a user’s troubles with GDI+. In particular, he found that he was unable to load JPG or PNG files stored as resources with GDI+. This article presents a way to make it happen.
This article was updated June 17, 204.
MrSID – searchStorage Definition Rate A definition from searchStorage.com. MrSID is an image compression format used primarily in mapping/GIS applications.
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Incredible Claims

Compression claims that defy conventional theory and/or practice.
Companies/Organizations

Pixelon Bites the Dust Rate
Pixelon shows what happens when technology gets mixed up with big bucks and shady characters. The Industry Standard ran a great story on it, but as they have gone belly up this link may not work any more. So this CNet news article will have to do.
Reader Tim A. points out that they also claim that ‘No longer is it necessary to produce complex waveforms by summing sinusoidal signals at varying frequencies’, yet later call their process an ‘additive reconstruction process’. Sounds much like the same process to me, just with different starting waveforms..
Web Technologies Rate
Byte looks back at the amazing compression claims of a company named Web Technlogies.
Wired Interviews ZeoSync CEO Rate Wired Magazine got ZeoSync CEO Peter St. George to sit down for a little chat. They posted the article here.
Slashdot Discusses Zeosync Rate The folks at Slashdot having their typical discussion re: the incredible claims from ZeoSync.
PCWorld: Questions Dog ZeoSync’s Compression Claim Rate PCWorld takes a skeptical look at Zeosync’s claims, and looks askance at the felony conviction of a key employee.
Take A HyperDrive On The Internet Super Highway Rate Pegasus Web Services has a new compression algorithm that they say can put 1.2GB on a floppy disk! No demo software yet, but if you’re interested in licensing the technology they are ready to talk.
Chaotic Compression? Rate Kevin Short at the University of New Hampshire has created a company called Chaoticom that is raising money to develop his new idea called Chaotic Compression Technology. Until we see some papers, algorithms, or products this is going to have to be categorized as an Incredible Claim.
Adam Clark Finds a Buyer Rate It appears that the technology promised by Adam Clark has found a buyer. MWC is paying $11 million for the IP that is reputed to be able to create a full-screen video experience over normal voice lines.
The Data Compression Newsletter #8 Rate This issue of the Data Compression Newsletter from DDJ highlights a few of the better Incredible Claims to come along – including the biggest of all, the Pixelon fraud case.
Newsgroup Posts

Compression of Random Data Rate
The comp.compression FAQ addresses this topic, reluctantly.
Fake Compression Programs Rate
Sadly, people will sometimes attempt to dupe the public. The FAQ chronicles some of these attempts.
Jules Gilbert Rate
Jules Gilbert has made a number of interesting and provocative posts to comp.compression. His claims have been met with vocal objections, but lack of public resolution will hamper the interested researcher.
No Magic Compressors Rate Charles Bloom explains why there is no Santa Claus.
Lynn Lantz Rate “I do believe that my product is superior to all other compression algorithms to date. It is lossless, works on any file type on any platform, is recursive (ie, the compressed file can be compressed again, and then again, and so on) so that ANY size file can be compressed to 16 bytes or less. I know this sounds like “perpetual motion” but it does work and I can prove it.”
Radpack.c Rate Charles Bloom works up a quick coder that will compress random bytes down to about 6 bits per byte. Quite a feat, but it doesn’t stand up to close scrutiny.
Teddy Turner Mixed Up In Compression Lawsuit Rate Teddy Turner, son of CNN mogul Ted Turner, was apparently named in a lawsuit in 1999 over an alleged misrepresentation of compression claims. A Florida company named Vision Tek claimed it could pump video over normal phone lines at high speeds, but was not able to satisy its investors, leading to a court case.
Mathematical Combinations and Compression Rate The comp.compression newsgroup regularly sees posts from folks with incredible compression claims. This one, started by Itai Bar-Haim, is remarkable not so much for its claims, but rather for the incredible length of the thread it spawned. All Atai said was that mathematical combinations have nothing to do with compression. So there.
Non-Commercial Libraries

Lzip Rate
Lossy data compression which can reduce input files to 0% of their size. Hint: product was released April 1, 2000.
DCL reader Tim A. marvels: Wow! it’s even faster than tarring to /dev/null!
Non-Commercial Programs

Hash Zip Rate
Hash Zip attempts to store 256 byte blocks by hashing them down to 30 byte blocks. Decompression seems problematic.
Demasoni Rate Demasoni is working on a revolutionary new data compression method, using something called the Starr Transform.
Papers/Documentation

Data Compression Newsletter #20 – Randomness and Complexity Rate This issue of the newsletter talks about randomness, complexity, and a long-time favorite, recursive compression.
Autosophy Information Theory Rate Klaus Holtz has some interesting ideas about compression theory.
Patents/Licenses

Relational Differentiation Encoding Patent App from Zeosync Rate
The folks at Zeosync have been making some pretty bold claims regarding their yet-to-be-shown compressin tools. This patent application might open the door a bit.
People

The $5000 Compression Challenge Rate
Patrick Craig has an interesting tale to tell. Without being a data compression expert, he managed to beat the $5000 compression challenge. You won’t see him taking an ocean cruise with his winnings, though. DCL reader commented: The challenge was obviously met.
Florida Compression Scheme Nets Millions Rate
This isn’t a new story, but the Florida Times-Union of Jacksonville gives a lot of detail in this treatment. A fellow named Madison Priest seems to have pulled in millions with his promises of hardware that can push high quality movies over conventional phone lines. Lots of interesting details, including the famous coax line hidden in the power cord! The second part of this story can be found here.
Sending TV Down the Phone Line Rate
ADAM CLARK could be sitting on an invention with the potential to turn the computer world on its head, not to mention the worlds of telecommunications and broadcasting. The 22-year-old Knoxfield developer claims to have cracked a conundrum that has stumped researchers for years – how to deliver broadcast quality sound and video down plain old telephone line.
Note: there is a $1AUS charge for viewing this article. :-(
Results

Tolly Group Report on Adams Platform Rate Miracle video encoding technology verified by this Australian testing firm.
Source Code

Radpack.c Rate Charles Bloom works up a quick coder that will compress random bytes down to about 6 bits per byte. Quite a feat, but it doesn’t stand up to close scrutiny.
Tutorials, Reference, Presentations

Magic Function Theory This is a recurring theme in comp.compression, which I call “The Magic Function Theory.” It sounds like a good idea, but analysis shows that it won’t work.
Ultimate Recursive Lossless Compression Research Rate
The name says it all. A research project dedicated to recursive compression.
Data Compression Newsletter #13 Rate
This issue of the Data Compression Newsletter from Dr. Dobb’s Journal looks at an idea for compression that doesn’t quite pan out.
MINC Lossless Digital Data Compression System Rate Back in 1998 I heard from a poor soul who was being encouraged to put some money into the Premier America, makers of the MINC Compression System. Seeing that MINC promised an iterative compression system that guaranteed any ratio you cared to dial in, I encouraged him to run, not walk, away from this opportunity. This led to an email conversation with someone from the company, assuring me that they would have a real product on the market quite soon now.
I haven’t heard a peep out of Premier America since then, so hopefully they have stopped raising funds for their unlikely system. Fortunately, a good soul named Chez DuLac has preserved MINC’s manifesto on his web site, along with his reasoned rebuttal.

HoloDynamic Compression: Mapping Miracles into the Machine Rate A great example of an incredible compression claim. There’s just a teeny tiny bit good thinking in here, and a huge amount of tangential speculation attempting to walk upright on two legs. Read it and just be glad the author doesn’t seem to be raising funds.
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Information Theory

Information Theory is an umbrella term for the scientific disciplines that attempt to codify the mathematical underpinnings of data. In particular, Information Theory is interested in topics such as data compression, data communications, and error correction
[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Books

Introduction to Information Theory and Data Compression (Discrete Mathematics and Its Applications Series) Rate by Hankersson et. al. Hardcover – 330 pages (November 1997) CRC Press; ISBN: 0849339855. A textbook for upper-level or graduate course on compression. Please use the link on this page to purchase this book, it will help support the Data Compression Library.
Introduction to Information Theory and Data Compression Rate Home page for the book: Introduction to Information Theory and Data Compression Darrel Hankerson, Greg A. Harris, and Peter D. Johnson Jr.
Buy from Amazon.com
Bibliography of Claude Elwood Shannon Rate This bibliography is the best attempt at a complete record of all the written works of Claude Shannon, father of Information Theory.
Elements of Information Theory Rate by Thomas M. Cover, Joy A. Thomas. This is an introductory text on Info Theory, covering all the basics, which of course includes coding and data compression.
Claude Elwood Shannon : Collected Papers Rate According to the publisher, this contains all of Shannon’s published works, plus papers that were previously unpublished for various reasons, including wartime secrecy.
Data Compression Bibliography Rate The University of Washington has a nice bibliography here, with pointers to books on Data Compression, VQ, Wavelets, and Information Theory.
Information Theory Rate by Robert B. Ash. This book gets a couple of five star ratings on Amazon.com. If you’re the type to pay close attention to your budget, you’ll like the fact that it sells for under $10!
Information Theory, Inference and Learning Algorithms Rate This book by David MacKay can be downloaded chapter by chapter and printed out for free. No indication that you can buy a hardcopy, although Amazon.com claims it will be published in January, 2002. Please read this 600 page tome and provide a review for this space!
Update: The author tells me this book will be published in November, 2003. The book will remain viewable on his website!
Companies/Organizations

IEEE Information Theory Society Web Portal Rate
The home page for the society. Links to newsletters, conferences, tutorials, abstracts, and other miscellaneous fun things.
Quantum Random Number Generation Rate This web site offers you random numbers generated using quantum process, which sounds like the gold standard to me.
Courses/Seminars

A Short Course in Information Theory Rate
8 lectures by David J.C. MacKay January 1995. Cavendish Laboratory, Cambridge, Great Britain. All of these lectures are available as PostScript files. The eight lectures cover data compression, coding, arithmetic coding, noisy channel coding, and much more
International Symposium on Information Technology: Coding and Computing ITCC 2000 Rate
Sponsored by IEEE Computer Society March 27-29, 2000, Las Vegas, Nevada
Topics include, but are not limited to, the following:

Digital Image Processing Data Storage Platforms
Document Image Analysis Optical Data Transmission
Data Compression New Architectures for Multimedia
Authentication of Video and Audio Processing
Data Graphics and Video Hardware
Multimedia Computing Error Control Codes
Hybrid Source/Channel Coding Video and Audio Codec Design
Systems Interfacing and Enterprise Architectures
Integration Enterprise-wide Information
Information Databases Management
Information Theory Research Group Rate
Home page for John C. Kieffer, Dept. of EE, University of Minnesota. Includes course descriptions for classes on data compression and information theory. The course descriptions have links to some papers.
EE376B/Statistics 376B: Information Theory Rate
A course outline from Stanford.
Information Theory Rate Lecture notes for a course on Information Theory, by John Lafferty, School of Computer Science, Carnegie Mellon University. Includes handouts, problem sets, code, additional lectures, and a page of links.
CMPE 263 Handouts by Glen Langdon Rate A set of handouts for a survey course on Data Compression, inlcuding papers on various types of coding, information theory, and more. An academic approach to the topics but quite accessible.
German

AG Information und Komplexität Rate A nice set of links to various resources related to info theory and data compression. German language.
Japanese Language Resources

Mitsuharu ARIMURA’s Bookmarks on Source Coding/Data Compression Rate
An enormous page of data compression links, well organized by type. Although this page is hosted in Japan, nearly all of the links are described in English.
Links

The Green Tree Of Compression Methods Rate
A Practical Introduction To Data Compression by Alexander Ratushnyak. A Data Compression mini-FAQ with a good set of links.
Mitsuharu ARIMURA’s Bookmarks on Source Coding/Data Compression Rate
An enormous page of data compression links, well organized by type. Although this page is hosted in Japan, nearly all of the links are described in English.
Entropy-Related Software Rate
Links to software, organized into three categories: Tutorials, Freeware, and Payware. Organized by Chris Hillman.
University of Washington Data Compression Laboratory Rate
Current research projects in our lab include research into vector quantization (VQ), wavelets, image compression, edge detection using VQ, VQ for image browsing, VQ design for noisy channels, halftoning, and color palette management.
Information Theory Research Group Rate
Home page for John C. Kieffer, Dept. of EE, University of Minnesota. Includes course descriptions for classes on data compression and information theory. The course descriptions have links to some papers.
Information Theory, Pattern Recognition and Neural Networks Rate
Some sort of class outline, including lots of links and references.
Entropy on the World Wide Web Rate Chris Hillman’s page of links to Information Theory pages, papers, etc.
Entropy in Information and Coding Theory Rate Like all of Chris Hillman’s pages, a nice set of links.
Gerry Wolf’s home page, Rate Gerry Wolf’s home page, including links to “Language Learning as Compression”, “Computing as Compression”, and “Cognition as Compression”
AG Information und Komplexität Rate A nice set of links to various resources related to info theory and data compression. German language.
Incompressible String Rate The definition from the NIST Dictionary of Algorithms and Data Structures.
Entropy on the web Rate Describe as Some resources of information theory and entropy concepts on the Internet.
Newsgroup Posts

More than one bit per bit? Rate Charles Bloom discusses the hopelessness of thinking you can get something for nothing.
The 2nd law of stat-mech in info-theory Rate Charles Bloom puts that physics background into play in the world of information theory.
Shannon’s derivation of the entropy function Rate Charles Bloom with his take on the work of Our Founder.
Mathematical Combinations and Compression Rate The comp.compression newsgroup regularly sees posts from folks with incredible compression claims. This one, started by Itai Bar-Haim, is remarkable not so much for its claims, but rather for the incredible length of the thread it spawned. All Atai said was that mathematical combinations have nothing to do with compression. So there.
Minimum Entropy Rate Charles Bloom discusses just what Minimum Entroyp should mean to you.
Blocked Entropy Rate More thoughts about entropy shared with us from Charles Bloom.
How Big is Nothing? Rate Charles Bloom puts the noggin to work on this question. It’s not as foolish as the title might make it sound.
Non-Commercial Programs

Ent Rate This page describes a program, ent, which applies various tests to sequences of bytes stored in files and reports the results of those tests. The program is useful for those evaluating pseudorandom number generators for encryption and statistical sampling applications, compression algorithms, and other applications where the information density of a file is of interest
Papers/Documentation

An Entropy Primer Rate
An introduction to Shannon’s notion of probabilistic entropy, from the viewpoint of ergodic theory and dynamical systems theory. Includes a complete proof a reasonably general (and useful!) version of the Asymptotic Equipartition Principle (AEP). Includes figures.
Symbol Ranking Text Compression with Shannon Recodings Rate
by Peter Fenwick, Department of Computer Science, The University of Auckland.
In his work on the information content of English text in 1951, Shannon described a method of recoding the input text, a technique which has apparently lain dormant for the ensuing 45 years. Whereas traditional compressors exploit symbol frequencies and symbol contexts, Shannon’s method adds the concept of “symbol ranking”, as in `the next symbol is the one third most likely in the present context’.

University of Washington Data Compression Laboratory Rate
Current research projects in our lab include research into vector quantization (VQ), wavelets, image compression, edge detection using VQ, VQ for image browsing, VQ design for noisy channels, halftoning, and color palette management.
Information Theory, Pattern Recognition and Neural Networks Rate
Some sort of class outline, including lots of links and references.
A Mathematical Theory of Communication by Claude E. Shannon Rate A reprint of an important paper. This site has links to the paper in PDF and Postscript formats. Claude E. Shannon is widely acknowledged to be the father of Information Theory. The publication of this paper established that reputation and gave birth to this area of scientific endeavor.
Lectures on Statistical Modeling Theory Rate A paper by Jorma Rissanen, IBM Almaden Research Center.
Entropy on the World Wide Web Rate Chris Hillman’s page of links to Information Theory pages, papers, etc.
Information and Computation Rate A journal that publishes papers dealing with randomness, pseudorandomness, and Kolmogorov complexity, among other things. Their home page features an on line listing of every paper published in this journal since 1957, with a search tool.
Information Theory Primer Rate A very gentle introduction to Shannon’s discrete entropy, written for moleculary biologists.
Reader Mike said To the point explanation of the “why” of some of the math. This allows you to look a symbols and understand the _meaning_ not just the math..
Bibliography of Claude Elwood Shannon Rate This bibliography is the best attempt at a complete record of all the written works of Claude Shannon, father of Information Theory.
Claude Elwood Shannon : Collected Papers Rate According to the publisher, this contains all of Shannon’s published works, plus papers that were previously unpublished for various reasons, including wartime secrecy.
A Mathematical Theory of Communication Rate by Claude Shannon. This paper is generally credited with being the opening kickoff of the science of Information Theory.
IEEE Transactions on Information Theory Rate The whole contents of the journal, dating back to 1953. If only you were a member of the society, you could read all these great papers.
CMPE 263 Handouts by Glen Langdon Rate A set of handouts for a survey course on Data Compression, inlcuding papers on various types of coding, information theory, and more. An academic approach to the topics but quite accessible.
IEEE Transactions on Information Theory Rate Links to the articles from this journal dating back to 1988. If you’re not an IEEE member, you only get to see the abstracts! Membership in the IEEE plus a few extra bucks lets you download here to your heart’s content.
Update: Site has moved due to redesign.
Data Compression Newsletter #20 – Randomness and Complexity Rate This issue of the newsletter talks about randomness, complexity, and a long-time favorite, recursive compression.
People

Claude Shannon (1916 – ) Rate
A short but informative thumbnail of Claude Shannon, along with a few links.
Jeff Vitter Rate Email address for Jeff Vitter, prolific author of papers which frequently include data compression topics
G J Chaitin Rate G.J. Chaitin seems to be interested in complexity and information theory.
Claude Shannon – Bit Player Rate An article in the New York Times that gives a thumbnail description of Claude Shannon. You will need to register with the Times in order to read the article.
Claude Shannon (1916 – ) Rate Shannon’s entry in the Information Science Hall of Fame web page.
The significance of Shannon’s Work Rate A salute to Claude Shannon from Bell Labs.
Claude Shannon Rate A bio on Shannon, plus some links.
Claude Elwood Shannon Rate A short bio, plus some links to more information on Shannon.
Information Theory – Who Created It? Rate A small web page with some info about Claude Shannon and what he meant.
Shannon Statue Rate A bronze statue of Claude Shannon will be unveiled on Friday, October 6, 2000 in his hometown, Gaylord, Michigan. This sculpture by Eugene Daub was commissioned by the Information Theory Society of the Institute of Electrical and Electronics Engineers (IEEE). It will be installed in the recently named Shannon Park in downtown Gaylord.
Bibliography of Claude Elwood Shannon Rate This bibliography is the best attempt at a complete record of all the written works of Claude Shannon, father of Information Theory.
Claude Who? Rate Robert X. Cringely waxes on a bit about the death of Claude Shannon. Bob definitely gives the Father his props.
Claude Shannon: Reluctant Father of the Digital Age Rate Loving article about the father of Information Theory in MIT’s Technology Review.
Tjalling J. Tjalkens Rate Tjalling is on the faculty of Technische Universiteit Eindhoven, which appears to be located in Eindhoven, The Netherlands. He is involved in research of various aspects of Information Theory, including Context Tree Weighting and Coding.
Tutorials, Reference, Presentations

The Green Tree Of Compression Methods Rate
A Practical Introduction To Data Compression by Alexander Ratushnyak. A Data Compression mini-FAQ with a good set of links.
Information Content and Compression Limit FAQ Rate
How much can a given piece of data be compressed? This FAQ addresses that question, including some necessary critiques of the question itself. Graham Fyffe apparently spends some time thinking about complexity.
Maximum Entropy and Overlapping Events Rate
The purpose of this applet is to help develop intuition about maximum entropy distributions. A central advantage of the maximum entropy framework is its ability to model overlapping events without increasing the number of parameters or fragmenting the training data. Using maximum entropy techniques, it is possible to model a probability distribution on 2n elements using only n free parameters.
Generating random numbers Rate An article by Eric Uner talks a bit about generating reandom numbers, something we all want to do from time to time.
Introduction to Data Compression Rate A set of slides, maybe to accompany a lecture. Covers basic info theory and data compression.
Wikipedia entry: Information Theory Rate The Wikipedia entry for Information Theory. The basic “Claude Shannon invented all this stuff” overview.
Incompressible String Rate The definition from the NIST Dictionary of Algorithms and Data Structures.
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Info-ZIP

Info-ZIP is a group of programmers that have created and now maintain two free programs: Zip and UnZip. These two programs perform canonical archive functions on Zip format archives that are compatbile with those created by PKWARE’s commercial PKZip line of products.
[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Companies/Organizations

Info-ZIP Rate
Info-ZIP is a diverse, Internet-based workgroup of about 20 primary authors and over one hundred beta-testers, formed in 1990 as a mailing list hosted by Keith Petersen on the original SimTel site at the White Sands Missile Range in New Mexico.
Info-ZIP’s purpose is to provide free, portable, high-quality versions of the Zip and UnZip compressor-archiver utilities that are compatible with the DOS-based PKZIP by PKWARE, Inc.

Non-Commercial Libraries

Zippity Do Dah Rate
Al Williams wrote an excellent article on using the Info-Zip DLLs to manipulate Zip files. There are lots of commercial libraries that let you access Zip files, but your choices in free software are few and far between. So if you need a free solution, Al’s article is a must-read. Many thanks to Al for getting this back on line after Visual Developer’s web site disappeared.
Non-Commercial Programs

Zip 2.3 Rate
The InfoZip project’s page for Zip, their free archive program that creates PKZip compatible archives
UnZip Rate
Everything you wanted to know about UnZip, one of the two great Info-ZIP programs.
UnZIp 5.51 shipped in May, 2004/
Zip for Macintosh Rate A port of the InfoZip programs to the Macintosh.
WiZ 5.02 Rate A graphical front end for Zip and UnZip. Binaries available for multiple varieties of Windows.
Zip and Unzip Using VB5 or VB6 Rate This code shows how to use the freeware InfoZip Zip32.DLL and Unzip32.DLL files from the http://www.cdrom.com/pub/infozip/ website. The InfoZip DLL’s are open-source DLL’s that are available for programmers to utilise free of charge. They are standard C DLLs and were very tricky/impossible to interface with VB until VB5/6 offered the ‘addressof’ operator.
Papers/Documentation

Recent Info-ZIP News and Ancient Info-ZIP History Rate
Info-ZIP News, History and Other Stuff
Source Code

Zip and Unzip Using VB5 or VB6 Rate
Some sample code and a tutorial explaining how to use the InfoZip DLLs with VB.
WiZ 5.02 Rate A graphical front end for Zip and UnZip. Binaries available for multiple varieties of Windows.
Zip and Unzip Using VB5 or VB6 Rate This code shows how to use the freeware InfoZip Zip32.DLL and Unzip32.DLL files from the http://www.cdrom.com/pub/infozip/ website. The InfoZip DLL’s are open-source DLL’s that are available for programmers to utilise free of charge. They are standard C DLLs and were very tricky/impossible to interface with VB until VB5/6 offered the ‘addressof’ operator.
Tutorials, Reference, Presentations

Zip and Unzip Using VB5 or VB6 Rate
Some sample code and a tutorial explaining how to use the InfoZip DLLs with VB.
Zippity Do Dah Rate
Al Williams wrote an excellent article on using the Info-Zip DLLs to manipulate Zip files. There are lots of commercial libraries that let you access Zip files, but your choices in free software are few and far between. So if you need a free solution, Al’s article is a must-read. Many thanks to Al for getting this back on line after Visual Developer’s web site disappeared.
Info-ZIP Frequently Asked Questions (FAQ) Rate
The FAQ for the Info-ZIP project.
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Internet

Compression techniques oriented specifically towards networking techniques, such as accelerating Web Browsers.
[ Deja News ] Search compression newsgroups for references to this topic
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Amazon Honor System
Commercial Programs

Artera Turbo Rate
These guys describe their product as Virtual Broadband, implying that it speeds up your dialup connection to the point that you can’t believe it’s not broadband! It appears that the product routes requests for web pages through their network, sending you to pages that have been compressed using their proprietary techniques.
User Paul was quite pleased with the service, saying All in all I was suitably impressd especially when I tried in on my lap top with my GSM connection. Cute to see everything speed up the way it did. .
w3compiler Rate
This is a compiler for web pages, that uses various techniques to squeeze the fat out of your web pages. This includes things a simple as white-space reduction and as complex as JavaScript compression.
Ron M. had this to say: This is a great program, very highly recommended for Web developers. It lets you write your code full of comments and extra space for readability, and then strips it all out automatically for the live site. My pages have been noticeably faster & very hard to decipher the code on the other end. It’s been reliable and easy to get used to.
TurboIIS Rate
A server and download accelerator for your Microsoft web server. The site says that TurboIIS is an advanced component for Microsoft Internet Information Servers, designed specifically with the aim of lowering band consumption, accelerating download times of static and dynamic content, and preventing redundant access to database resources. 30 day trial download available!
Reader Alfred S. had this to say: Very impressive performance compared to other similar products.
Version 4.0 is shipping as of December, 2003.
TIS Turbo Virtual Broadband Rate This system uses data compression and other optimization techniques to speed up your dialup Internet connection. This sytem works with any ISP or provider.
SlipStream Internet Acceleration Rate SlipStream Data, using our patented proprietary data compression algorithm, provides Service Providers and Corporations with solutions that reduce bandwidth and increase the speed of Internet access using dial-up and wireless connections.
Version 3.0 of SlipStream is shipping in May, 2003.
HTML2Zip Rate This product compresses your web pages using the gzip format, which is readable by virtually every modern browser. Compressing the pages this way can do a lot to improve your page loading times.
Version 2.0 is shipping in April, 2003.
HTMLCompact Rate HTMLCompact is a commercial program that squeezes your HTML pages, giving you faster downloads and increased user retention. It appears that this is done using some sort of compression that is executed in JavaScript.
Version 2.0 of this product is shipping as of August, 2003.
HTML-Optimizer Rate This program is designed to optimize your HTML source files by removing unnecessary characters, duplicated tags, and so on. Yes, this counts as Data Compression! Note that this link points to the Windows version of the program, but there are also two different Mac versions which you can easily find.
Version 7.82 was shipping in october of 2003.
WebWrap Rate WebWrap is a small 3-in-1 utility program to compress and/or code your HTML web files. It uses either a modified LZSS algorithm or the URL encryption procedure, and can reduce the size of your files by more than 50%. It also renders the source of any HTML pages you have created, your design features and your scripts for example, inaccessible to easy viewing or simple clip and paste procedures. The “WebWrapped” files you create are self-extracting and do not require any third-party software. In addition to compressing and coding your HTML files, you also have the opportunity to add automatically a password protection script.
Advanced HTMLCoder Rate This product is designed to optimize, compress, and encrypt your HTML pages, which makes them load more quickly and protects them from casual copying.
HTML Page Guardian Rate This product is used to protect the source of your HTML pages, which it does using “three layers of encryption.” I don’t know how that works, but they do advertise that LZW compression is an optional part of the process, so they earn a spot in DataCompression.info.
httpZip Rate httpZip uses standard algorithms to compress web pages streaming out of your IIS server. This commercial software adds support, installation programs, and administration to provide you with something a cut above some of the free alternatives.
WebZIP Rate This commercial product will zip up entire web sites and download them to your PC. You can then view them off line, at your leisure.
Attachments Zip Compressor Rate This commercial product takes care of managing your attachments. It appears to do this transparently, so you don’t even have to think about zipping up a big attachment before sending.
ZipEnable for IIS Rate Unlike the compression built into IIS 4 and 5 (Windows NT/2000), IIS 6.0 offers out-of-the-box compression embedded into the core Web server code itself, allowing for extremely fast HTTP compression with minimal resource penalties.
Version 2.0 is shipping as of May, 2004.
OutlookZIP Rate The OutlookZIP it’s an Add-On for Microsoft® Outlook. It makes easy for you to compress the files that you attach to Microsoft® Outlook e-mail messages. OutlookZIP adds three buttons to Outlook toolbar making the usage simple easy. OutlookZIP works only with Outlook 2000, Outlook XP (2002), and Outlook 2003. It does not work with Outlook Express.
VIGOS Website Accelerator Rate Vigos makes software that lets you compress web pages before delivering them to your customers.
Companies/Organizations

Expand Networks Rate
Expand makes a series of Network Accelerators. These are black boxes that perform lossless compression on packets being shipped across our WAN. Lots of competition in this area, so companies like Expand depend on innovative and proprietary techniques to give them an edge.
Peribit Rate
These folks make a box that transparently compresses network traffic. Designed to work on any sort of WAN interface, including T1, E1, ATM, etc. The web site includes an ROI calcuator that will convince you this box will pay for itself!
Talleo Rate Talleo advertises themselves as an international telecommunications consulting firm that provides Network Engineering, WAN optimization, and data compression. They are a reseller of Peribit’s products.
German

Zipserver Rate Zipserver is a little HTTP server that serves up static documents from inside Zip files. Great way to put manuals or archived documents on line, don’t you think?
Hardware

Expand Networks Rate
Expand makes a series of Network Accelerators. These are black boxes that perform lossless compression on packets being shipped across our WAN. Lots of competition in this area, so companies like Expand depend on innovative and proprietary techniques to give them an edge.
Peribit Rate
These folks make a box that transparently compresses network traffic. Designed to work on any sort of WAN interface, including T1, E1, ATM, etc. The web site includes an ROI calcuator that will convince you this box will pay for itself!
ITWorx Rate These folks make NetCelera, a WAN compression product.
Links

Webcompression.org Rate This site is dedicated to discussion and explanation of HTTP compression with the Apache web server. Looks to me like the first place to go for information.
Non-Commercial Libraries

Flatcompression Rate This open source project is working on an ISAPI compression filter, designed for use with IIS. The project is listed as being in beta status by the maintainer, with hopeful comments for the future in the SourceForge discussion forums.
ModZipRead Rate Mod ZipRead is an Apache 2 module to browser Zip Archives. It uses zziplib.
Non-Commercial Programs

Javascript Compression Rate
Another compressor for HTML or Javascript files. This looks to be a Javascript implementation. Looks free.
GrepMail Rate This nifty program searches through a normal or compressed mailbox looking for strings. Supports Gzip, Bzip2, and tzip formats.
LightSpeed Website Optimizer Rate This program does as much optimization of your web pages as possible, all in an effort to reduce its size and hence the time it takes users to D/L the page. Free!
HTML Compressor Rate A program that mungs HTML files in order to make them smaller. Some safe optimizations, some unsafe. Not really compression so much as optimization. Note: I’ve classified this as non-commercial, because the web site makes no mention of any kind regarding payment. I might be wrong.
Zipserver Rate Zipserver is a little HTTP server that serves up static documents from inside Zip files. Great way to put manuals or archived documents on line, don’t you think?
GNUNetPress Network Compression Rate GNUNetPress – Network compression client/server software. Compresses data over slow networks to save on the cost of bandwidth. Server is developed for Unix platforms, The client will run on Linux or Windows based PCs.
Ziproxy Rate This is a web proxy that compresses pages using standard gzip compression, making them a lot smaller for serving up over low-speed connections. Not only does it convert text to gzip encoding, it also converts images to low-quality JPEGs for maximum space savings.
Version 1.3b is shipping as of November, 2003.
WebGraph Rate This project aims to compress the graph created by spidering the web. They claim 3.8 bits per link, which seems pretty incredible to me.
Compreso Rate Compreso implements compressed sockets using an LZH algorithm, as implemented by Rolando Herrero. It does this cooperatively with the Win32 socket library, so you can only run this code under Windows. Freeware.
MngZilla Rate The project to maintain a version of Mozilla that supports MNG format animated graphics.
Source Code

A JavaScript Compression Tool for Web Applications Rate A CodeProject article which includes working code. Compression here consists of removal of comments, extra line feeds, white space, etc.
Standards

Delta encoding in HTTP Rate A draft proposal for delta encoding for text sent via HTTP.
Tutorials, Reference, Presentations

Why use HTTP Compression? Rate A quick tutorial on how and why to use HTTP compression when delivering your web pages.
HTTP Compression Speeds up the Web Rate An article describing the way compression can speed up the web, along with a nifty demo. Unfortunately, links to the demo seem to be broken.
HTTP Compression Rate Brian Livingston’s short article on HTTP compression provides some pointers detailing how to configure your server to serve compressed content.
Compressing Web Content Rate Compressing Web content can produce a much faster site for users. Here’s how to set it up and measure your success.l
A JavaScript Compression Tool for Web Applications Rate A CodeProject article which includes working code. Compression here consists of removal of comments, extra line feeds, white space, etc.
Webcompression.org Rate This site is dedicated to discussion and explanation of HTTP compression with the Apache web server. Looks to me like the first place to go for information.
Compress Your PHP4 Pages Rate Gzip encoding is a great way to serve up your web pages, because all modern browsers can render this format. If you’re creating pages with PHP4, it turns out to be really easy to compress your pages this way and get a bit of speedup.
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Italian

Resources in the Italian Language.
Backup

ZipGenius Rate Zipgenius is yet-another-archiver. Supports 21 different compression formats, plus a pretty long list of extras, such as FTP support, email, backup functions, and more. The long list of features might make you expect a price tag, but ZipGenius is in fact free!
Version 5.5.1.440 of ZipGenius is shipping as of June, 2004.
Burrows-Wheeler Transform/Block Sorting

Giovanni Manzini Rate
Giovanni Manzini has published papers covering a few different topics in Data Compression, including several recent works on Burrows-Wheeler algorithms. He is currently an Associate Professor of Computer Science at the Universita degli Studi del Piemonte Orientale in the the most northern reaches of Italy.
Paolo Ferragina Rate
Paolo Ferragina’s research in data structures and string matching naturally lends itself to Data Compression and to the problem of indexing compressed data. See the link to his recent papers on indexing BWT compressed files. He is currently an Associate Professor of Computer Science at the University of Pisa.
Data Compression

Giovanni Manzini Rate
Giovanni Manzini has published papers covering a few different topics in Data Compression, including several recent works on Burrows-Wheeler algorithms. He is currently an Associate Professor of Computer Science at the Universita degli Studi del Piemonte Orientale in the the most northern reaches of Italy.
Paolo Ferragina Rate
Paolo Ferragina’s research in data structures and string matching naturally lends itself to Data Compression and to the problem of indexing compressed data. See the link to his recent papers on indexing BWT compressed files. He is currently an Associate Professor of Computer Science at the University of Pisa.
Esoterica/Miscellany

C Library to search over compressed texts Rate
A team from the University of Pisa in Italy have created a set of two libraries to demonstrate the ability to perform searches in compressed text. The code is packaged as two LGPL libraries: HuffwLib and CGrepLib, and sample programs are available on the site for demonstration purposes.
Huffman Coding

C Library to search over compressed texts Rate
A team from the University of Pisa in Italy have created a set of two libraries to demonstrate the ability to perform searches in compressed text. The code is packaged as two LGPL libraries: HuffwLib and CGrepLib, and sample programs are available on the site for demonstration purposes.
Lossless Compression

Telvox Software Shop Rate
This site has links to Telvox’s CODEC package, which appears to ship in both free and commercial versions. CODEC uses proprietary lossless compression, and is ported to a wide variety of platforms. Telvox is located in Bologna, Italy, and has duplicate web pages in English and Italian.
MPEG

Flask MPEG Rate
The home site for the Flask MPEG conversion program. A program that can convert back and forth between MPEG-1 and MPEG-2. Change parameters such as frame rate, etc. Free!
Speech

Compressione della voce a 2.4 Kbit/s Rate Part of a Master’s Thesis on voice compression, in Italian.
Zip

PentaZip Rate
PentaZip has a very nice feature set, supports advanced encryption, large archives, Windows shell integration, and all the other good stuff you’ve come to expect. Also supports a wide variety of languages.
Release 6.0.1.190 shipped in November, 2003
ZipCentral Rate
ZipCentral is a free and easy to use zip file manager with all the utilities you need to manage your zip files. The goal of ZipCentral is to be the most robust freeware zip-package you can find today. It is a great tool for the beginner as well as the expert. Working with zip files has never been easier!
ZipGenius Rate Zipgenius is yet-another-archiver. Supports 21 different compression formats, plus a pretty long list of extras, such as FTP support, email, backup functions, and more. The long list of features might make you expect a price tag, but ZipGenius is in fact free!
Version 5.5.1.440 of ZipGenius is shipping as of June, 2004.
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Japanese Language Resources

References to sites that provide data compression information in Japanese
Archiving

Common Archives Library Project Rate
Home page for the Common Archivers Library project. This page is completely in Japanese, but an English version of the index is available at a single click. The goal of this project appears to be to provide standard library software that works with any and all archives. Good idea.
Compact Pro Rate Compact Pro is a shareware file compression and archival utility for the Mac. It compresses and stores files in “archives” which may span multiple diskettes. Compact Pro supports data encryption (US and Canadian users only) and self-extracting archives.
Audio

TwinVQ Rate
An audio compression format invented at NTT’s Cyber Space Laboratories. Get your player and compressor right here. (English avaible by following the sharp-eyed link.)
Data Compression

Mitsuharu ARIMURA’s Bookmarks on Source Coding/Data Compression Rate
An enormous page of data compression links, well organized by type. Although this page is hosted in Japan, nearly all of the links are described in English.
Data Compression Pointers Rate A set of data compression links maintained by Haruhiko Okumura. Many of the links here point to Japanese language sites. Even if you cannot read Japanese, you may still profit from the profusion of links on this page. Just be sure your browser is set to render Shift-JIS.
Data Compression in Japan Rate I need a translation of this page from any interested volunteer.
Unknown Rate I need a translation of this page from any Japanese speaking volunteers.
Bibliography on Source Coding/Data Compression Rate Mitsuharu Arimura’s page of links and references to a wide variety of papers and books on lossless compression. Some of the links are listed in English, others in Japanese.
Gzip

Easy-GZ Rate Easy-GZ is a compression tool which allows extremely tight compression and quick decompression. Based on the GZip standard and optimized for the Macintosh platform, an easy-to-use, effective GZ compressor has finally been brought to the Mac OS. Is this software free or not? I’m putting it in the free category – if you find out otherwise please send me an email.
Information Theory

Mitsuharu ARIMURA’s Bookmarks on Source Coding/Data Compression Rate
An enormous page of data compression links, well organized by type. Although this page is hosted in Japan, nearly all of the links are described in English.
LHA

Micco’s Home Page Rate
Home of LHMelt, UNLHA32.DLL, UNARJ32.DLL. All text on this page is in Japanese, except for a single link pointing to English information on UNLHA32.DLL.
LHA Source code site Rate FTP site that contains LHA source code. Most of this page is in Japanese.
MacLHA support Rate This web site is run by the author of MacLHA, a drag and drop version of LHA for Mac OS. You can also get access to a drag and drop LHA expander for Mac OS here.
DropLHA for Mac OS/X Rate A site that has a port of a drag and drop version of LHA to Mac OS X. My Japanese referrer tells me this version does not support MacBinary so resource forks will be lost by this program.
LZ78/LZW and derivatives

Unisys LZW Page Rate
Some information on LZW, it looks as though this has info on Licensing, but I’m not sure. All information is in Japanese.
PNG

Taking Advantage of libpng Rate Reputedly an excellent set of resources for using libpng – but don’t take my word for it – my Japanese is non-existent.
Quantization

TwinVQ Rate
An audio compression format invented at NTT’s Cyber Space Laboratories. Get your player and compressor right here. (English avaible by following the sharp-eyed link.)
zlib

Zlib Rate A Japanese language site that is somehow related to zlib.
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JBIG

JBIG is a standard algorithm for lossless compression of still images. JBIG and JPEG were contemporaries, but JPIG never achieved the popularity of JPEG. It remains to be seen whether lossless JPEG2000 will succeed in popularizing a standard form of lossless image compression.
[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Commercial Libraries

Image Power Downloads Rate
Image Power has their products available for download here, which includes the commercial version of PowerCompressor, and a beta copy of Jasper, a JPEG2000 codec.
Companies/Organizations

The JBIG Home Page Rate
Home page for the members of the JBIG committee, as well as a place for links and information about the Bi-Level Image coding standard.
Home site of the JPEG and JBIG committees Rate
As it says, this is the home site of the committees. You need to be a member to access some areas, but there is plenty of information here for the common man as well.
Tak’Asic Rate
Tak’Asic provides Lossless/Lossy still image compression/decompression ICs solution.
. Our ICs support JBIG, MH, MR, MMR and JPEG standards.
Our latest product, Tak’B3, is the world fastest JBIG codec available. It is able to process images at 133Mpixel/sec minimum and up to 2128Mpixel/sec. It also provides code conversion (MR/MR/MMR <-> JBIG) and scaling functionality.
Hardware

The Qx-coder Rate
IBM’s implementation of arithmetic coding known as the Q-coder is a well-known piece of work. (Patented, unfortunately.) This paper discusses an implementation of the Q coder in hardware.
Tak’Asic Rate
Tak’Asic provides Lossless/Lossy still image compression/decompression ICs solution.
. Our ICs support JBIG, MH, MR, MMR and JPEG standards.
Our latest product, Tak’B3, is the world fastest JBIG codec available. It is able to process images at 133Mpixel/sec minimum and up to 2128Mpixel/sec. It also provides code conversion (MR/MR/MMR <-> JBIG) and scaling functionality.
Links

The JBIG Home Page Rate
Home page for the members of the JBIG committee, as well as a place for links and information about the Bi-Level Image coding standard.
The DICOM Standard Rate This page gives a short introduction to the DICOM standard, commonly used for medical imaging. It has a lengthy set of links to DICOM viewers, images, and other resources.
Medical Image Format FAQ – Part 7 Rate Lots of pointers here. Relevant to compression because of the wealth of pointers to various formats used in medical imaging, such as JPEG-LS and Lossless JPEG.
Newsgroup Posts

Introduction to JBIG Rate
The comp.compression FAQ gives you this introduction.
Non-Commercial Libraries

JBIG Kit Rate Markus Kuhn has this to say about it: I wrote the freely available JBIG-KIT 1.2 portable ANSI C library, which implements a highly effective lossless bi-level image compression algorithm based on context sensitive arithmetic coding. The JBIG algorithm (specified in ITU-T Recommendation T.82), which is implemented in this library, is especially suitable for compressing scanned documents and fax pages. You can also download the (unfortunately German) project report (Studienarbeit) that I wrote about JBIG-KIT (abstract).
Release 1.6 available as of 6/2004.
JBIG2DEC Rate A JBIG2 decoder open source project, described as being O/S independent. The alpha releases are capable of decoding some JBIG2 documents but aren’t ready for prime time yet.
Version 0.4 was released July 31, 2003.
Non-Commercial Programs

JBIG files Rate
Here you will find information and tools related to the JBIG arithmetic lossless bi-level image compression algorithm. This includes the JBIG kit, which is a free C lossless image compresion library that conforms to the JBIG specification.
Papers/Documentation

Signal Processing and Multimedia Group – Univ. of British Columbia Rate
Software for H.263, JPEG-LS, and JBIG-2. Follow the links to Software. Many publications as well.
JBIG files Rate
Here you will find information and tools related to the JBIG arithmetic lossless bi-level image compression algorithm. This includes the JBIG kit, which is a free C lossless image compresion library that conforms to the JBIG specification.
The Qx-coder Rate
IBM’s implementation of arithmetic coding known as the Q-coder is a well-known piece of work. (Patented, unfortunately.) This paper discusses an implementation of the Q coder in hardware.
Home site of the JPEG and JBIG committees Rate
As it says, this is the home site of the committees. You need to be a member to access some areas, but there is plenty of information here for the common man as well.
Fast Progressive Lossless Image Compression Rate P. G. Howard and J. S. Vitter. “Fast Progressive Lossless Image Compression,” Proceedings of the 1994 IST/SPIE International Symposium on Electronic Imaging Science and Technology, San Jose, CA, February 1994. This paper describes a technique that combines the author’s previously published FELICS algorithm with the progressivity of the MLP method.
A JBIG-ABIC compression engine for digital document processing Rate A paper describing the creation of a compression engine that was later implemented in firmware.
Performance as a function of compression Rate This IBM research paper looks into the performance of compressors in relation to the compressibility of the the objects they are compressing. At least I think that’s what it is talkinga bout.
FELICS – Fast and Efficient Lossless Image Compression Rate P. G. Howard and J. S. Vitter. “Fast and Efficient Lossless Image Compression,” Proceedings of the 1993 IEEE Data Compression Conference (DCC ’93), Snowbird, UT, April 1993. The abstract describes this as a lossless compression algorithm that provides results as good as JPEG in lossless mode with five times the speed.
Source Code

Signal Processing and Multimedia Group – Univ. of British Columbia Rate
Software for H.263, JPEG-LS, and JBIG-2. Follow the links to Software. Many publications as well.
JBIG files Rate
Here you will find information and tools related to the JBIG arithmetic lossless bi-level image compression algorithm. This includes the JBIG kit, which is a free C lossless image compresion library that conforms to the JBIG specification.
JBIG Kit Rate Markus Kuhn has this to say about it: I wrote the freely available JBIG-KIT 1.2 portable ANSI C library, which implements a highly effective lossless bi-level image compression algorithm based on context sensitive arithmetic coding. The JBIG algorithm (specified in ITU-T Recommendation T.82), which is implemented in this library, is especially suitable for compressing scanned documents and fax pages. You can also download the (unfortunately German) project report (Studienarbeit) that I wrote about JBIG-KIT (abstract).
Release 1.6 available as of 6/2004.
Standards

JBIG Standard – ITU T.82 Rate
This is the ITU page where you can purchase a copy of the JBIG specification for the modest price of 29 CFH. (You don’t really expect them to give this stuff away, do you?)
JBIG files Rate
Here you will find information and tools related to the JBIG arithmetic lossless bi-level image compression algorithm. This includes the JBIG kit, which is a free C lossless image compresion library that conforms to the JBIG specification.
Home site of the JPEG and JBIG committees Rate
As it says, this is the home site of the committees. You need to be a member to access some areas, but there is plenty of information here for the common man as well.
Tutorials, Reference, Presentations

The DICOM Standard Rate This page gives a short introduction to the DICOM standard, commonly used for medical imaging. It has a lengthy set of links to DICOM viewers, images, and other resources.
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JPEG

JPEG is a standard method of lossy image compression based on the DCT transform. JPEG’s support by standard Internet browsers led to its becoming a highly adopted standard.
[ Deja News ] Search compression newsgroups for references to this topic
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Amazon Honor System
Books

Sample pages on DCT Rate
Sample pages on line from the book Discrete Cosine Transform: Algorithms, Advantages, Applications by Kamisetty Ramamohan Rao, P. Yip. The first 6 pages of the book are excerpted here, giving a complete history of the DCT.
Bilddatenkompression/Image Data Compression Rate
Subtitled Basics, Standards and Wavelet-Based Algorithms for Image and Video Coding. This German-language textbook contains full source code (ANSI-C) of a wavelet-based image coder.
Compressed Image File Formats: JPEG, PNG, GIF, XBM, BMP by John Miano Rate
“Compressed Image File Formats is an appealingly compact and useful guide to some of today’s most popular file formats used for image data. For any programmer who needs to know how images are stored, this concise reference can serve as a really invaluable resource.”
Note that the source code for this book includes an independent implementation of a PNG codec, which may be one of a kind. Link to the source code on this page.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Commercial Libraries

Pegasus Medical Compression Toolkit Rate
Pegasus Imaging, a developer of high performance imaging software, today announced its new Medical Compression Toolkit product, a set of compression libraries intended to address specific needs in the medical imaging community. The Medical Compression Toolkit is a set of libraries for various image compression methods which have been adapted for medical use.
DCL reader reported: I used this tool for implementing Motion JPEG compression/decompression for 24-bit color, 800×600 medical images at frame rate of 30 on dual PIIIs. It is a good tool..
PICTools Imaging Library by Pegasus Imaging Rate
Pegasus Imaging Corporation, Tampa FL.announces the release today of new version of the PICTools imaging libraries for software developers.
PICTOOLS RAPIDVUE Rate The Fastest JPEG engine available! Pegasus high speed JPEG engine offering the fastest JPEG compression and decompression available based on algorithmic optimization, assembly level enhancements, Pentium II and Pentium III optimization.
Arcsoft Mobile Media Codecs Rate Arcsoft has a line of mobile media codecs that includes support for MIDI, JPEG, PNG, GIF, and speech.
Commercial Programs

JPEG Cruncher Pro Rate
JPEG Cruncher is a commercial app that lets you squeeze the heck out of your images while keeping them looking as nice as possible.
Advanced JPEG Compressor for Windows Rate
A program that helps you cook up the optimal version of your JPEG file.
Motion-JPEG CODEC Rate
MainConcept makes a codec that encodes things in the Motion-JPEG format.
JPEG Wizard by Pegasus Imaging Rate For those individuals looking for an application that deals with all aspects of JPEG imaging–The JPEG Wizard is it! The JPEG Wizard is based around the premise that altering and processing an image at the algorithmic level instead of the visual level greatly preserves the quality of an image.
2JPEG Rate 2JPEG is a graphics converter allowing you to convert images to jpeg format from 50+ image file types including conversions from bitmap to jpeg, from gif to jpeg, from tiff to jpeg and so on. The program has no windows interface and is fully optimized for working in background mode.
JPEG Enhancer Rate This product fixes artifacts and defects in your JPEG images.
Version 1.0 shipped in December, 2003.
JPEG Imager JPEG Imager Rate JPEG Imager is an interactive image compressor. It provides real-time preview of compressed image and handy means to compare it with original one. You can fiddle with various compression parameters and observe the effect of changes straight away. You also can specify a desired file size and let the program select the proper values automatically. It is perfect for “Quality vs. File Size” optimization.
PICPress Rate An image conversion program that does smoothing of JPEG images.
Interactive JPEG Optimizer Rate A tool to help you reduce the size of your image files with little or no reduction in image quality. Demo version available, fully functional but stamps output files with a “Demo” label.
Companies/Organizations

Pegasus Imaging Corporation Rate
Pegasus Imaging Corporation has their fingers in many different pies, mostly related to imaging and image compression. This home page has links to many of their diffferent products, a variety of programs and libraries.
Morgan Multimedia. Rate
This company makes a M-JPEG codec and would like to sell it to you. Much of the page is written in French.
Home site of the JPEG and JBIG committees Rate
As it says, this is the home site of the committees. You need to be a member to access some areas, but there is plenty of information here for the common man as well.
Independent JPEG Group Rate
The Independent JPEG Group is a source of free JPEG software. It is in wide use. Oddly enough, the groups home page doesn’t have anything interesting on it except a link to an ftp site, and a link to a couple of FAQs.
Tak’Asic Rate
Tak’Asic provides Lossless/Lossy still image compression/decompression ICs solution.
. Our ICs support JBIG, MH, MR, MMR and JPEG standards.
Our latest product, Tak’B3, is the world fastest JBIG codec available. It is able to process images at 133Mpixel/sec minimum and up to 2128Mpixel/sec. It also provides code conversion (MR/MR/MMR <-> JBIG) and scaling functionality.
Signal and Image Processing Group Rate The University of Bath has a group that is advertised as “world leaders in still image and video coding.” They appear to be interested in lossy compression based on DCT, Wavelets, and Fractal compression. This is their home page.
divio Rate Self-described leader in digital video and imaging technology, divio has a product line that includes hardware that implements MPEG-4, AAC, M-JPEG, and JPEG. Suitable for inclusion in both digital still and movie cameras.
Forgent’s Press Release on JPEG Patent Rate Forgent explains their position with respect to the infamous ‘672 patent.
Zoran Corporation Rate Zoran makes chips that do some MPEG decoding as well as JPEG codecs.
French

Morgan Multimedia. Rate
This company makes a M-JPEG codec and would like to sell it to you. Much of the page is written in French.
Digital Photography from Agfa Rate A complete short course on digital photography from Agfa. It shows up here because Lesson 6 is on The Right Compression. You get a discussion of various formats, including GIF, JPEG, JPEG2K, and PNG. Best of all, it looks like the entire page is available in English, German, Spanish, and Portuguese.
German

Bilddatenkompression/Image Data Compression Rate
Subtitled Basics, Standards and Wavelet-Based Algorithms for Image and Video Coding. This German-language textbook contains full source code (ANSI-C) of a wavelet-based image coder.
Digital Photography from Agfa Rate A complete short course on digital photography from Agfa. It shows up here because Lesson 6 is on The Right Compression. You get a discussion of various formats, including GIF, JPEG, JPEG2K, and PNG. Best of all, it looks like the entire page is available in English, German, Spanish, and Portuguese.
Hardware

DSPWorx Cheetah – DSW2000S Chip Rate
This System-on-chip provides you with all the building blocks you need to perform several different kinds of compression and decompression, including MPEG, JPEG, and JPEG2000.
Tak’Asic Rate
Tak’Asic provides Lossless/Lossy still image compression/decompression ICs solution.
. Our ICs support JBIG, MH, MR, MMR and JPEG standards.
Our latest product, Tak’B3, is the world fastest JBIG codec available. It is able to process images at 133Mpixel/sec minimum and up to 2128Mpixel/sec. It also provides code conversion (MR/MR/MMR <-> JBIG) and scaling functionality.
Oak Technology JPEG Image Processor Rate The PM-36 is a chip that is touted as processing up to 110 MB of data per second. Oak says it is suitable for copiers, printers, scanners, etc.
TI sampling encoding chips for digital cameras Rate TI is pushing its ARM and DSP cores into the digital camera market, with chips that support conventional imaging as well as MPEG-2 and MPEG-4 video.
divio Rate Self-described leader in digital video and imaging technology, divio has a product line that includes hardware that implements MPEG-4, AAC, M-JPEG, and JPEG. Suitable for inclusion in both digital still and movie cameras.
ViCAM®-III Digital Imaging Engine Rate Vista Imaging makes this chip, designed to do the image processing needed for several different types of digital cameras. Among many other features, it has a JPEG compression engine.
Zoran Corporation Rate Zoran makes chips that do some MPEG decoding as well as JPEG codecs.
Links

Signal and Image Processing Group Rate The University of Bath has a group that is advertised as “world leaders in still image and video coding.” They appear to be interested in lossy compression based on DCT, Wavelets, and Fractal compression. This is their home page.
Web Graphics Rate A tutorial page discussing the various image formats currently in use on the web. Nice comparisons and a good set of links.
JPEG – Information Links Rate A page of links from the JPEG committee.
Guido’s Tech Corner Rate Guido Vollbeding has posted a number of items related to the IGJ code. Includes ways to crop, rotate, and merge JPEG files.
Newsgroup Posts

Tell me about Fast DCT (Discrete Cosine Transform) algorithms Rate
The comp.compression FAQ attempts to do just that.
Introduction to JPEG Rate
The comp.compression FAQ provides you with an introduction.
What is JPEG? Rate
The comp.compression FAQ attempts to answer this question.
Non-Commercial Libraries

Corona Rate
Corona is an image input/output library that can read, write, and manipulate image files in just a few lines of code. It can write PNG files, and read PNG, JPEG, PCX, BMP, TGA, and GIF. Corona was designed to be easy to use, and exports a straightforward C++ API. With just a few lines of C++, you can add image loading to your application.
Corona 1.0.1 shipped in May, 2003, and added support for TGA images as well as a few more functions.
Data Compression Newsletter #12 – Using Intel’s JPEG Library Rate
This issue of the Data Compression Newsletter from Dr. Dobb’s has some sample code showing how one might use Intel’s JPEG library to display JPEG files under Win32.
JPEG Library Rate
Intel has a C/C++ JPEG library that works with Visual C++ under Win32. It would appear that their motivation is to distribute code that is optimized for the MMX extensions in their processor. License agreement has a few points that should be examined, but essentially it appears to be free. Please correct me if I’m wrong.
One reviewer of this site had this to say: I tried out the IJL library. It was slower than the Independent JPEG Group code. I was using IJL 1.5.
Vlandimire says: I use this library, v. 1.51 works very well.
Independent JPEG Group Rate
The Independent JPEG Group is a source of free JPEG software. It is in wide use. Oddly enough, the groups home page doesn’t have anything interesting on it except a link to an ftp site, and a link to a couple of FAQs.
A free C++/MFC source code image framework with jpeg and dib codecs Rate
Free MFC source code for displaying JPEG files. Completely free, can be used in commercial products.
DCL User Comment: Very slow and awkward to work with…
Common Lisp JPEG Library Rate JPEG compression and decompression routines in ANSI Lisp.
MMXDCT Rate MMXDCT is an implementation of 8×8 FDCT/IDCT with MMX technology. With the help of MMX, only about 1000 CPU cycles are needed to do an 8×8 IDCT.
Intel’s PII Inverse DCT Application Notes Rate Intel has a nice document showing how one can optimize the inverse DCT when running on processors with the MMX instructions, such as the Pentium II. Listings include code you can drop into the Independent JPEG Group’s library.
DCL reader Neil H. had this to say: The drop-in replacement for the iDCT of the IJG works fine for 8-bit data (not 12-bit). It reduced total compression time to 2/3 or so of the original cross-platform code. The iDCT itself is supposed to be 4x faster.
PASJPEG Rate PASJPEG is a port of the sixth public release of the IJG C source (release 6a of 7-Feb-96) [3], that implements JPEG baseline, extended-sequential, and progressive compression processes to Turbo Pascal 7.0 for DOS (TP). The code has been tested under Delphi 2.0 [6], it can be ported to other Pascal environments, since many compilers try to be compatible to TP.
libExif Rate A library that allows you to parse and read the meta-tag content in EXIF files. C code, but no comments regarding compilers or platforms.
The ExifReader class Rate A .NET library for reading EXIF metadata from JPEG files.
OpenExif Toolkit Rate This toolkit lets you access EXIF metadata that has been stored in JPEG files, typically from a digital camera.
libDSP Rate A C++ library of digital signal processing routines. We link to it here because it includes a DCT algorithm, plus a few other possibly interesting routines.
mjpgTools Rate mjpgTools is an encapsulation of the JPeGlib and MJPeGtools and several other useful routines into a single Win32 DLL. This is an Open Source project, so have at it.
jpg2html Rate jpg2html converts JPEG images into HTML. A series of jpg2html procedures are being written to explore different means and different effects.
codecs.org Rate codecs.org is a meta-project containing a wide range of tools and libraries designed to improve the state of codecs and their optimization. This includes libcodec, which contains routines for forward and reverse DCTs, MPEG motion compensation and estimation, block placement, etc.
Classes to read and write BMP, JPEG and JPEG 2000 Rate Tony Lin created some classes that can read these three popular image formats, and includes an MFC demo app. The Jasper coder is used for JEPG2K support.
Non-Commercial Programs

JPEGDUMP from Colosseum Builders, Inc. Rate
This application dumps the contents of JPEG blocks in a JFIF file.
JPEG Group free software – 32 Bit Versions Rate
This distribution contains MS-DOS 32 bit extended executable copies of version 6b of the Independent JPEG Group’s free JPEG software. Several different programs for conversion and manipulation of JPEG files.
Privacy For Pictures Rate This paper from Jürgen Abel and Bill Teahan presents several preprocessing algorithms for textual data, which work with BWT, PPM and LZ based compression schemes. The algorithms need no external dictionary and are language independent. The average compression gain is in the range of 3 to 5 percent for the text files of the Calgary Corpus and between 2 to 9 percent for the text files of the large Canterbury Corpus.
mjpeg-jpegs Rate mjpeg-jpegs is a tool for coverting Motion-JPEG files such as the short movies produced by digital cameras to JPEG files and back. Both AVI and QuickTime formats are supported, including audio tracks.
Release 0.1.0 is shipping as of March, 2004
Epic24 Rate From the site: Epic24 is a GUI program that I wrote to interactively compare graphic compression codecs against each other. It currently contains JPG, Lossless JPG, JPEG 2000, (Jasper Library Implementation), PNG, John Robinson’s BTP and ATP, and finally my own lossless graphics compression called IMPLODE (IMage Predictive LOssless Decoder Encoder).
The JPEG Online Laboratory Rate An online version of the jpegtran utility from the IJG. Upload an image and muck about with it.
Scilab Image Processing Toolbox Rate SIP intends to do imaging tasks such as filtering, blurring, edge detection, thresholding, histogram manipulation, segmentation, mathematical morphology, color image processing, etc. These operations are useful for problem solving in real-world applications ranging from car motion planning to automatic diagnosis of medical images.
Version 0.3.1 is shipping as of May, 2004.
Zip/JPEG Mask and Encryption Rate This cool program uses either Zip file or JPEG file to encrypt some of your data. I think it’s free, email me if I’m wrong.
An Image Viewer with Lossless Rotation, EXIF and Other Goodies Rate Frank Eden’s article on The Code Project web site is summed up quite well by the title. About the only thing I have to add is to point out that it is designed to work with JPEG images.
jpegpixi Rate “Jpegpixi” is short for “JPEG pixel interpolator”. It is a command-line utility which interpolates pixels in JFIF images (commonly refered to as “JPEG images”). This is useful to correct images from a digital camera with CCD defects. Jpegpixi is unique in that it tries to preserve the quality of the JFIF image as much as possible
Optimizer Rate A visual tool that lets you degrade image files with visual feedback on how you are doing. A good, easy way to minimize the size of files before using them on your web page, tec.
Jpegpixi Rate This open source Linux project performs a very specialized task. It is used to repair images that have single pixel errors, such as that you might get from a camera with a single bad spot on the CCD. It interpolates from the neighboring pixels to create a new value, then inserts it without a decompress/recompress cycle. Pretty neat!
JPEG Group free software Rate This distribution contains MS-DOS executable copies of version 6b of the Independent JPEG Group’s free JPEG software. Several different programs for conversion and manipulation of JPEG files.
JPEG to MJPEG-AVI converter Rate This Open Source Linux project does one thing and one thing only: it converts a series of JPEG files to an AVI MJPEG file. On the SourceForge tracking system this project is labeled as being Beta, but it is up to release 1.2, so I’m guessing this is no longer the case.
Version 1.2 is shipping as of March, 2003.
jpegrdf Rate This program is used to read and manipulate the RDF metadata that can be stored in JPEG images.
Version 2.0 is shipping as of February, 2004.
kdc2tiff Rate Software to convert the proprietary KDC files produced by Kodak digital cameras into JPEG or TIFF format. Appears to work under Linux only.
Papers/Documentation

Home site of the JPEG and JBIG committees Rate
As it says, this is the home site of the committees. You need to be a member to access some areas, but there is plenty of information here for the common man as well.
JPEG Compression Algorithm and Associated Data Structures Rate A paper by Mark D. Schroeder at the University of North Dakota. This paper talks a bit about implementation issues for JPEG.
A faster way to downscale during JPEG decoding to a fourth Rate A paper by Stefan Kuhr describing a technique that he developed. It improves performance when decoing using the IJG library.
Baseline JPEG and JPEG2000 Artifacts Illustrated Rate This paper by Aleks Jakulin discusses the artifacts that show up in images compressed using the JPEG and JPEG2000 algorithms. He includes some nice sample images to illustrate what he is talking about.
Smoothing DCT Compression Artifacts Rate A paper from SID Digest by Ahumada, A. J., Jr.and Rensheng Horng. Getting rid of those annoying DCT artifacts is obviously a big deal for those of you using JPEG and MPEG compression.
Perceptual Optimization of DCT Color Quantization Matrices Rate A paper by Andrew Watson from NASA Ames Research Center. This paper describes a procedure called DCTune which is claimed to create DCT quantization matrices superior to the default ones used in the JPEG algorithm.
Image Compression Using the Discrete Cosine Transfer Rate This paper from the Mathematica Journal gives some introductory material on using Mathematica to do a bit of image compression.
A Non Uniform Segmentation Optimal Hybrid Fractal/dct Image Compression Algorithm Rate by Gerry Melnikov, Aggelos K. Katsaggelos. In this paper a hybrid fractal and Discrete Cosine Transform (DCT) coder is developed.
Patents/Licenses

Forgent Network Inc. claims IP-rights for JPEG Rate
A position paper from Dr. Klaus Jung and Prof. RuediSeiler, representing Algo Vision LuraTech GmbH. They show in some detail that Forgent’s claims on a patent that covers JPEG are not valid.
Reader John F. said: Goodbye Forgent and your lawyer pals at Jenkens and Gilchrist! We’ll see who has the last laugh on this deal, in the early part of 2003 this story has been very quiet.
Patent Claim Strikes an Electronics Nerve Rate The New York Times covers the Forgent JPEG case. A good overview of the case.
Forgent’s Press Release on JPEG Patent Rate Forgent explains their position with respect to the infamous ‘672 patent.
Finding patent truth in JPEG claim Rate An article on CNET regarding the Forgent JPEG patent. This article brings up the allegation that one of the patent authors sat on a JPEG committee.
No more JPEGs – ISO to withdraw image standard Rate The Register UK reports that the ISO may withdraw the JPEG image format standard if the Forgent ‘672 patent holds up.
Update: Forgent Claims Rights To JPEG Patent Rate ExtremeTech reports on the Forgent JPEG patent case.
JPEG Patent Claim Sparks Concern Rate Wired reports on the Forgent JPEG patent case.
JPEG group seeks prior art Rate The ISO committee responsible for the JPEG standard would like to track down prior art that might invalidate the Forgent patent.
People

Tom Lane Rate email address for Tom Lane, organizer of the Independent JPEG group, omniscient poster to comp.compression on JPEG issues.
Portuguese

Digital Photography from Agfa Rate A complete short course on digital photography from Agfa. It shows up here because Lesson 6 is on The Right Compression. You get a discussion of various formats, including GIF, JPEG, JPEG2K, and PNG. Best of all, it looks like the entire page is available in English, German, Spanish, and Portuguese.
Results

Epic24 Rate From the site: Epic24 is a GUI program that I wrote to interactively compare graphic compression codecs against each other. It currently contains JPG, Lossless JPG, JPEG 2000, (Jasper Library Implementation), PNG, John Robinson’s BTP and ATP, and finally my own lossless graphics compression called IMPLODE (IMage Predictive LOssless Decoder Encoder).
Experiments in archival-quality image compression Rate Some image compression tests by Mike Muus, the author of ping.
Source Code

Data Compression Newsletter #12 – Using Intel’s JPEG Library Rate
This issue of the Data Compression Newsletter from Dr. Dobb’s has some sample code showing how one might use Intel’s JPEG library to display JPEG files under Win32.
JPEGDUMP from Colosseum Builders, Inc. Rate
This application dumps the contents of JPEG blocks in a JFIF file.
JPEG arithmetic encoding and decoding portable software implementation Rate
A back-end implemenation of arithmetic coding for JPEG as defined in the standard. It is distributed as an add-on that can be used with the Independent JPEG groups library. The work of Guido Vollbeding.
JPEG Group free software source Rate
Free, portable C code for JPEG compression is available from the Independent JPEG Group. Source code, documentation, and test files are included.
Privacy For Pictures Rate This paper from Jürgen Abel and Bill Teahan presents several preprocessing algorithms for textual data, which work with BWT, PPM and LZ based compression schemes. The algorithms need no external dictionary and are language independent. The average compression gain is in the range of 3 to 5 percent for the text files of the Calgary Corpus and between 2 to 9 percent for the text files of the large Canterbury Corpus.
IEEE Standard 1180-1990 accuracy test for IDCTs Rate From the archive: This archive contains a quick & dirty implementation of the IEEE Standard 1180-1990 accuracy test for inverse DCT. It is not guaranteed to be correct … but if you find any bugs, please let me know (by email totgl@cs.cmu.edu). Since the archive was created in 1993 I don’t know if you’ll have any luck with those bug reports!
Intel’s PII Inverse DCT Application Notes Rate Intel has a nice document showing how one can optimize the inverse DCT when running on processors with the MMX instructions, such as the Pentium II. Listings include code you can drop into the Independent JPEG Group’s library.
DCL reader Neil H. had this to say: The drop-in replacement for the iDCT of the IJG works fine for 8-bit data (not 12-bit). It reduced total compression time to 2/3 or so of the original cross-platform code. The iDCT itself is supposed to be 4x faster.
Standards

Home site of the JPEG and JBIG committees Rate
As it says, this is the home site of the committees. You need to be a member to access some areas, but there is plenty of information here for the common man as well.
OpenDML AVI File Format Extensions Rate
This document describes the proposed format of the OpenDML compliant AVI extensions, specifically for the Motion JPEG DIB AVI file. This format is an extension to the AVI M-JPEG DIB as defined in the JPEG DIB FORMAT technical note from Microsoft. The format is based on the ISO 10918 defined JPEG format.
Tutorials, Reference, Presentations

Data Compression Newsletter #12 – Using Intel’s JPEG Library Rate
This issue of the Data Compression Newsletter from Dr. Dobb’s has some sample code showing how one might use Intel’s JPEG library to display JPEG files under Win32.
JPEG FAQ Rate
The JPEG FAQ, as maintained by Tom Lane and the Independent JPEG group.
JPEG Compression Example Rate
An opportunity to look at a file when compressed with various JPEG quality factors.
JPEG Compression – Interactive Demo Rate
This page has a Java applet that lets you experiment a bit with different quantization schemes for JPEG. There is lots of information here, I highly recommend that you follow the Help link to see what’s going on.
Explanation of 2D DCT (Discrete Cosine Transform) Rate
Notes for an Info Theory course at MIT.
VIPER – The JPEG Tutorial Rate The Video and Image Processing Laboratory at Purdue has a tutorial page on JPEG. Good place to start when looking for introductory material.
Image Compression — JPEG Rate Class notes for a section on JPEG.
Web Graphics Rate A tutorial page discussing the various image formats currently in use on the web. Nice comparisons and a good set of links.
Functional Specification of the JPEG algorithm Rate A decoder for images compressed by the JPEG algorithm is stated in the pure functional programming language Gofer. The program can be regarded as a mathematical specification of the decompression algorithm; the concise description (which is included in full) is very suitable for learning about the algorithm. At the same time the `specification’ is an executable program, which shows the usefulness of a functional programming language as a prototyping tool for graphics algorithms
Wikipedia entry: JPEG Rate This Wikipedia entry describes JPEG image compression. A reasonable overview with helpful links.
JPEG baseline compression Rate A short description of JPEG baseline compression from the folks at DAKX, who offer a competing method of compressing analog data of all types.
Compression, Encoding and Graphics Files – A Practical Tutorial Rate Tutorial by Rich Holowczak from Rutgers U. A set of slides that would probably be really useful if you had the lecture to go with it. Without the lecture, not so hot.
Digital Photography from Agfa Rate A complete short course on digital photography from Agfa. It shows up here because Lesson 6 is on The Right Compression. You get a discussion of various formats, including GIF, JPEG, JPEG2K, and PNG. Best of all, it looks like the entire page is available in English, German, Spanish, and Portuguese.
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JPEG-2000

JPEG2000 is intended to be a new and improved image compression method that replaces both JPEG and JBIG. This next big thing uses wavelets as the basis for both lossy and lossless algorithms.
[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Books

Jpeg2000 : Image Compression Fundamentals, Standards, and Practice Rate
by David S. Taubman, Michael W. Marcellin. This rather pricey book is listed as a reference for engineers and researchers who want to understand the JPEG2000 standard. Taubman is the author of the Kakadu tools, which are included on the CD (licensing terms unknown.) Use the link on this web page to buy the book – you’ll help keep this site on line.
Commercial Libraries

Aware Inc. JPEG2000 Codec Rate
Aware makes a JPEG 2000 Codec and SDK, which includes libraries for both Win32 and UNIX. You can download a demo of their product from the web site should you be willing to provide a bit of contact data.
PICTools JPEG2000 Rate
This is the PicTools JPEG2000 SDK, which lets you drop JPEG2000 compression and decompression into your C/C++ programs. Pegasus Imaging makes quite a few compression library products. In this particular case, it appears they enlisted the help of Algo Vision plc to develop this product.
LEAD JPEG2000 Plugin for Adobe Photoshop Rate
Read and write JPEG2000 files from Photoshop with this plugin.
DataCompression.info reader Eric was disappointed with this product: Their plugin’s preview mode does not work. Without it, the plugin is horribly crippled. .
Kakadu Rate
The home page describes Kakadu thus: A comprehensive, heavily optimized, fully compliant software toolkit for JPEG2000 developers .
DataCompression.info user Tim A. gushed: A very fast implementation with a small memory footprint compared to Jasper and even other commercial implementations. Also handles large files better than all others I have tried. Very well done with motion JPEG2000, a viewer and a JPIP server to boot (and those are just the sample applications!). John J. added The best of any JPEG2000 compressors for lossless compression. Higher compression rates, and faster compression than Aware and Algo Vison Luratech.
Luratech Rate
Luratech has plugins and an SDK for both their proprietary format and JPEG2000. Products come in a dizzying array of options, ActiveX controls, C-SDK, Java-SDK, plugins for PhotoShop or browsers. Note that some of their products can now be downloaded as freeward!
Note: What was once LuraTech is now Algo Vision LuraTech.
Reader Tom H. says: Luratech is the fastest licensable SDK out there right now
TI releases DSP Developer Support for JPEG2000 Rate
Texas Instruments announced the release of a DSP based Image Developer’s Kit, with support coming for JPEG2000, MPEG-4, and other standards.
Image Power Downloads Rate
Image Power has their products available for download here, which includes the commercial version of PowerCompressor, and a beta copy of Jasper, a JPEG2000 codec.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
LEADTOOLS JPEG2000 Plugin Rate LEADTOOLS is now supporting JPEG2000 in their toolkits by means of this JPEG2000 plugin. Supports both file and stream formats, plus many additional features. Download of sample available.
THBJpeg2000 Rate This product is an addon to the THBImage Library. The Library is available as either a DLL or OCX, and supports a wide variety of image formats and operations. An 30-day evaluation version is available for download.
Commercial Programs

RomSoft JPEG2000 libraries and plugins Rate
JPEG200 products provided by RomSoft. Here you find a C++ DLL implementation of JPEG2000 Part 1 standard (ISO/IEC 15444-1) and a Photoshop plugin for JPEG2000 and J2K files
Reader Petrut D. had this to say:
One of the fastest JPEG2000 codecs out there. The Intel IPP library helped a lot with performance. I also tried the Photoshop plug-in, and managed to open all the test files from http://www.crc.ricoh.com/~gormish/jpeg2000conformance/J2KP4files/ part 0 and part 1. The plug-in handled JP2 and J2K images from 1 bit to 16 bit signed/unsigned flowlessly. Highly recomend the C++ DLL and the Photoshop plugin.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
LEADTOOLS JPEG2000 Plugin Rate LEADTOOLS is now supporting JPEG2000 in their toolkits by means of this JPEG2000 plugin. Supports both file and stream formats, plus many additional features. Download of sample available.
AMC-JPEG2000 Rate This product converts your photos to JPEG-2000 format to speed up the process of sending them by mail. And how do your friends view these photos when they get them? Well, it appears that AMC will be happy to give them a free JPEG 2000 viewer.
SouthDowns Rate SouthDowns is a set of Perl scripts for the creation of JPEG 2000 files from JPEG 2000 codestreams. If you’re interested in the format used by the standard, this might be an easy way to experiment with it. The sample program appears to insert some metadata into the image file.
Warning: this release has no release information and no licensing information!
PhotoNav Rate PhotoNav is a commercial optimized mega-image navigator system based on JPEG-2000. An alpha version of the PhotoNav client is now available for Palm handhelds. This software lets you browse JPEG-2000 images on your PDA.
JPEG 2000 Project Related Links Rate Links to several projects that are working with JPEG 2000 technology.
Companies/Organizations

WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
Migrator 2000 Rate This group says that they will develop, demonstrate and disseminate tools for the JPEG 2000 digital imaging standard. At this time that seems to include a couple of demonstration programs, some text and web pages, test images, and a link to a Perl package.
Files

JPEG 2000 Part 4 Conformance Test Files Rate Part 4 of the standard relates to conformance. The files on this site are used in conformance testing. This web site implies that this part of the standard will soon be available for free, but as of March, 2003, this is not the case.
JPEG 2000 Code and Test Data Rate This page contains links to sample code and test data for implementing the JPEG 2000 standard. Looking for conformance files? This is the place. Looking for working implementations? You can find several here.
French

Digital Photography from Agfa Rate A complete short course on digital photography from Agfa. It shows up here because Lesson 6 is on The Right Compression. You get a discussion of various formats, including GIF, JPEG, JPEG2K, and PNG. Best of all, it looks like the entire page is available in English, German, Spanish, and Portuguese.
German

JPEG 2000 Dropper Rate
A free Max OS X program that converts your images to JPEG 2000.
Luratech Rate
Luratech has plugins and an SDK for both their proprietary format and JPEG2000. Products come in a dizzying array of options, ActiveX controls, C-SDK, Java-SDK, plugins for PhotoShop or browsers. Note that some of their products can now be downloaded as freeward!
Note: What was once LuraTech is now Algo Vision LuraTech.
Reader Tom H. says: Luratech is the fastest licensable SDK out there right now
Digital Photography from Agfa Rate A complete short course on digital photography from Agfa. It shows up here because Lesson 6 is on The Right Compression. You get a discussion of various formats, including GIF, JPEG, JPEG2K, and PNG. Best of all, it looks like the entire page is available in English, German, Spanish, and Portuguese.
Hardware

DSPWorx Cheetah – DSW2000S Chip Rate
This System-on-chip provides you with all the building blocks you need to perform several different kinds of compression and decompression, including MPEG, JPEG, and JPEG2000.
TI releases DSP Developer Support for JPEG2000 Rate
Texas Instruments announced the release of a DSP based Image Developer’s Kit, with support coming for JPEG2000, MPEG-4, and other standards.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
JPEG2000 Bi-directional Image Coprocessor Chip Rate Analog Devices makes a JPEG2000 processor that can process better than 10 Megapixels per second. This chip is targeted towards the digital still camera market. You can find a press release on the page that says initial pricing is $14 in 10K quantities.
JPEG200 In Accelerator Chip Rate Analog Devices has announced an acceleratory chip that supports the JPEG2000 image compression format. The chip is targeted towards digital still cameras, and is available now for $14 in quantitites.
Chinese JPEG2000 business on runway Rate This article in EE Times describes an effort to steer the Chinese digital camera business onto the JPEG-2000 road. The goal is to create a chip that can be inserted into cameras for less than $10. The supplier of the algorithm used in the chip is WIS Technologies.
FREE Print Subscriptions Printer friendly versionEmail a Colleague Star IP Cores Target ASIC/FPGA Implementation Rate Amphion Semiconductor has announced the development of ASIC- and FPGA-targeted versions of the company’s hardware-accelerator cores for MPEG-4, MPEG-2, and JPEG2000 compression applications. The new “Star IP” cores are also equipped with AHB interfaces that are compatible with the AMBA specification for on-chip system bus connectivity.
Links

JPEG 2000 Tools 2.0 Rate
Developed in the scope of MIGRATOR 2000 project (www.migrator2000.org), this site presents a graphical user interface to the three currently available codecs (VM, JJ2000, Jasper) as well as validation and parsing services to J2k codestreams and JP2 files. It’s currently a widely used tool within WG1 (JPEG) to perform compliance tests on coders and codestreams. Site requires free registration for purposes of tracking stored images.
JasPer: A Software-Based JPEG-2000 Codec Implementation Rate
Jasper is a C-language implementation of the JPEG-2000 Part-1 standard. Michael Adams seems to run the show, with help from Image Power and a small team. This page gives you access to the software, documentation, and a nice set of links. Jasper is distributed under a free license.
Version 1.701.0 is shipping as of February, 2004.
Viper – The JPEG 2000 Resource Page Rate
A page of links and information from the image processing folks at Purdue.
JPEG – Information Links Rate A page of links from the JPEG committee.
JPEG 2000 – Links to Information Rate The JPEG 2000 committee uses this as the main source of links to the JPEG 2000-related pages on their site. It also includes a friendly plug for a book by committee members, with a “Buy Me” link to Amazon.com.
Non-Commercial Libraries

Almacom JPEG-2000 library Rate
The page says: The Almacom JPEG-2000 library was written in an effort to produce the cleanest and simplest implementation possible of the JPEG-2000 standard. We have put a particular emphasis on good architecture design and code simplicity, while at the same time providing an implementation as complete and efficient as possible.
DataCompression.info user Luca M. said I was looking for a good library of wavelets. Now I’ve found it !
jp2IE – JPEG2000 ActiveX Control for Internet Explorer Rate
The jp2IE control is an extension of Microsoft’s Internet Explorer and allows the display of JPEG/JPEG2000 compressed files. It is based on the IJG implementation of the JPEG Standard Part 1/2 (ISO/IEC 10918-1/2) and the JASPER implementation of the JPEG2000 Standards Part 1 (ISO/IEC 15444-1).
Luratech Rate
Luratech has plugins and an SDK for both their proprietary format and JPEG2000. Products come in a dizzying array of options, ActiveX controls, C-SDK, Java-SDK, plugins for PhotoShop or browsers. Note that some of their products can now be downloaded as freeward!
Note: What was once LuraTech is now Algo Vision LuraTech.
Reader Tom H. says: Luratech is the fastest licensable SDK out there right now
JPEG 2000 Browser Plugin Rate Elysium says that this product is the first publicly released JPEG 2000 plugin for the Windows platform. It works with Netscape, Opera, and IE browsers, and is free.
Classes to read and write BMP, JPEG and JPEG 2000 Rate Tony Lin created some classes that can read these three popular image formats, and includes an MFC demo app. The Jasper coder is used for JEPG2K support.
Non-Commercial Programs

JPEG 2000 Tools 2.0 Rate
Developed in the scope of MIGRATOR 2000 project (www.migrator2000.org), this site presents a graphical user interface to the three currently available codecs (VM, JJ2000, Jasper) as well as validation and parsing services to J2k codestreams and JP2 files. It’s currently a widely used tool within WG1 (JPEG) to perform compliance tests on coders and codestreams. Site requires free registration for purposes of tracking stored images.
JasPer: A Software-Based JPEG-2000 Codec Implementation Rate
Jasper is a C-language implementation of the JPEG-2000 Part-1 standard. Michael Adams seems to run the show, with help from Image Power and a small team. This page gives you access to the software, documentation, and a nice set of links. Jasper is distributed under a free license.
Version 1.701.0 is shipping as of February, 2004.
JPEG 2000 Dropper Rate
A free Max OS X program that converts your images to JPEG 2000.
Epic24 Rate From the site: Epic24 is a GUI program that I wrote to interactively compare graphic compression codecs against each other. It currently contains JPG, Lossless JPG, JPEG 2000, (Jasper Library Implementation), PNG, John Robinson’s BTP and ATP, and finally my own lossless graphics compression called IMPLODE (IMage Predictive LOssless Decoder Encoder).
JPEG 2000 Code and Test Data Rate This page contains links to sample code and test data for implementing the JPEG 2000 standard. Looking for conformance files? This is the place. Looking for working implementations? You can find several here.
JPEG 2000 Project Related Links Rate Links to several projects that are working with JPEG 2000 technology.
Papers/Documentation

A study of JPEG 2000 still image coding versus other standards Rate
by Diego Santa-Cruz and Touradj Ebrahimi. This paper is to-be-published.
JPEG 2000, More Than New Millennium Buzz Rate An article on JPEG 2000 in WebReview. A pretty good description of what’s going to be in the standard.
JPEG 2000: Worth the Wait? Rate A paper by Michael J. Gormish from Ricoh in Silicon Valley. History, rationale, results, and procedures.
An Overview of JPEG-2000 Rate A paper by Michael W. Marcellin, Michael J. Gormish, Ali Bilgin, Martin P. Boliek that was published in the 2000 Proceedings of the DCC. Good information of only moderate complexity in an academic format.
An analytical study of JPEG 2000 functionalities Rate by Diego Santa-Cruz and Touradj Ebrahimi. A paper to be published in Proc. of the IEEE International Conference on Image Processing (ICIP), September, 2000.
JPEG2000, the next millenium compression standard for still Rate by Maryline Charrier, Diego Santa Cruz and Mathias Larsson. This short paper gives an overview of the JPEG2000 standard, along with a java decoder.
Region of Interest Coding in JPEG2000 for interactive client/server applications Rate A paper by Diego Santa Cruz, Touradj Ebrahimi, Mathias Larsson, Joel Askelöf and Charilaos Cristopoulos. According to the abstract, this paper discusses ways to decode regions of an image on the fly without needing to do a complete decode of the entire image.
Baseline JPEG and JPEG2000 Artifacts Illustrated Rate This paper by Aleks Jakulin discusses the artifacts that show up in images compressed using the JPEG and JPEG2000 algorithms. He includes some nice sample images to illustrate what he is talking about.
Documents from JPEG Committee Members Rate The papers pointed to here provide useful background information on the standard. There are seminar papers, tutorials, and other background documents.
JPEG 2000 Committee Documents Rate The JPEG 2000 committee publishes links to some of their documents here. (Notably absent: the standards themselves.) This includes links to standard drafts, press releases, and requirements.
People

David Taubman Rate David Taubman is on the faculty of the University of New South Wales, in Sydney, Australia. Taubman is the author of the book JPEG2000: Image Compression Fundamentals, Standards and Practice and has been very influential in the current development of the standard. He is also the author of Kakadu, a commercial library that is advertised as a complete implementation of Part 1 of the standard.
Portuguese

Digital Photography from Agfa Rate A complete short course on digital photography from Agfa. It shows up here because Lesson 6 is on The Right Compression. You get a discussion of various formats, including GIF, JPEG, JPEG2K, and PNG. Best of all, it looks like the entire page is available in English, German, Spanish, and Portuguese.
Results

Epic24 Rate From the site: Epic24 is a GUI program that I wrote to interactively compare graphic compression codecs against each other. It currently contains JPG, Lossless JPG, JPEG 2000, (Jasper Library Implementation), PNG, John Robinson’s BTP and ATP, and finally my own lossless graphics compression called IMPLODE (IMage Predictive LOssless Decoder Encoder).
Source Code

Almacom JPEG-2000 library Rate
The page says: The Almacom JPEG-2000 library was written in an effort to produce the cleanest and simplest implementation possible of the JPEG-2000 standard. We have put a particular emphasis on good architecture design and code simplicity, while at the same time providing an implementation as complete and efficient as possible.
DataCompression.info user Luca M. said I was looking for a good library of wavelets. Now I’ve found it !
JasPer: A Software-Based JPEG-2000 Codec Implementation Rate
Jasper is a C-language implementation of the JPEG-2000 Part-1 standard. Michael Adams seems to run the show, with help from Image Power and a small team. This page gives you access to the software, documentation, and a nice set of links. Jasper is distributed under a free license.
Version 1.701.0 is shipping as of February, 2004.
JJ2000 – An Implementation of the JPEG2000 Standard in Java Rate
JJ2000 is a Java implementation of a JPEG 2000 codec. The web site states that JJ2000 is under consideration to be a reference implemenation of the standard. JJ2000 is now freely available to all, and may be freely used in products that implement JPEG 2000-Part I.
The page also includes links to a white paper, presentations, and other related web pages.
Standards

JPEG 2000 Tools 2.0 Rate
Developed in the scope of MIGRATOR 2000 project (www.migrator2000.org), this site presents a graphical user interface to the three currently available codecs (VM, JJ2000, Jasper) as well as validation and parsing services to J2k codestreams and JP2 files. It’s currently a widely used tool within WG1 (JPEG) to perform compliance tests on coders and codestreams. Site requires free registration for purposes of tracking stored images.
JPEG 2000 – The Committee Draft Specification Rate
The committee draft of the JPEG2000 specification. This is not the final specification, but it should be very close.
Note: the Zip file disappeared sometime in July 2002, this link has been updated to point to a PDF version of the draft.
JJ2000 – An Implementation of the JPEG2000 Standard in Java Rate
JJ2000 is a Java implementation of a JPEG 2000 codec. The web site states that JJ2000 is under consideration to be a reference implemenation of the standard. JJ2000 is now freely available to all, and may be freely used in products that implement JPEG 2000-Part I.
The page also includes links to a white paper, presentations, and other related web pages.
JPEG2000 wavelet compression spec approved Rate
At long last the JPEG 2000 spec has been approved. Developers can now start working on products that will support this quantum leap in image compression.
Call for Contributions for JPEG 2000 Rate The original call for contributions for JPEG 2000. This is of course way out of date, but it may be of historical interest.
JPEG 2000 Part 6 Final Committee Draft Rate JPEG 2000 Part 6 refers to the standard for compound documents.
JPEG 2000 Metadata Rate Links to information on JPEG 2000 metadata, include the XML DTD and Schema for the JPEX metadata set.
Tutorials, Reference, Presentations

Short course: JPEG 2000 image coding standard Rate
Course notes of a JPEG 2000 short course given at the International Conference in Image Processing (ICIP). By Dr. Majid Rabbani and Diego Santa-Cruz. The course covers image coding principles, a review of JPEG and all the main elements of JPEG 2000: wavelet transform, entropy coding, bitstream structure, error resilience, functionality, performance evaluation, etc.
Pandora – Markup metadata inside JPEG 2000 files Rate
Pandora is a web-oriented application of JPEG 2000. It uses web pages as a novel example of XML metadata. A multi-image, multi-page website can be stored within a single JPEG 2000 file, and viewed using an ordinary web-browser.
The JPEG 2000 Standard Rate
A presentation by Michael J. Gormish & Michael W. Marcellin, which was given at the DCC in 2000. Lots of information and figures, but as always, the slides without the talk leaves one wanting more.
Viper – The JPEG 2000 Resource Page Rate
A page of links and information from the image processing folks at Purdue.
Digital Photography from Agfa Rate A complete short course on digital photography from Agfa. It shows up here because Lesson 6 is on The Right Compression. You get a discussion of various formats, including GIF, JPEG, JPEG2K, and PNG. Best of all, it looks like the entire page is available in English, German, Spanish, and Portuguese.
Return to The DataCompression.info home page
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Copyright © 2005 Visicron Corp. All rights reserved.
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JPEG-LS

JPEG-LS is the basis for new lossless/near-lossless compression standard for continuous-tone images intended for JPEG2000. The standard is based on the LOCO-I algorithm (LOw COmplexity LOssless COmpression for Images) developed at Hewlett-Packard Laboratories
[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Companies/Organizations

HP Labs LOCO-I/JPEG-LS Home Page Rate
JPEG-LS is the new lossless/near-lossless compression standard for continuous-tone images developed by ISO/IEC JTC1/SC29/WG1 (final draft international standard FDIS14495-1 as of Novembr 1998). The standard is based on the LOCO-I algorithm (LOw COmplexity LOssless COmpression for Images) developed at Hewlett-Packard Laboratories
Update: The HP site has just added a JPEG-LS plugin for Photoshop, in addition to the HP implementation that has been there for some time.
Home site of the JPEG and JBIG committees Rate
As it says, this is the home site of the committees. You need to be a member to access some areas, but there is plenty of information here for the common man as well.
Links

Medical Image Format FAQ – Part 7 Rate Lots of pointers here. Relevant to compression because of the wealth of pointers to various formats used in medical imaging, such as JPEG-LS and Lossless JPEG.
Non-Commercial Libraries

Lossless JPEG Codec Rate
A freely redistributable lossless JPEG codec. Encoder, decoder, man pages, full C source, and some documentation.
LOCO-I/JPEG-LS Software Download Page Rate
HP offers some free JPEG-LS software, including a Windows DLL, PhotoShop plugin, and reference executables good on several platforms, including Windows, Linux, Solaris, and of course, HP-UX.
One anonymous reader dissed the package with this comment: Not particularly user friendly.
JPEG-LS Public Domain Code Rate A free implementation of the upcoming JPEG-LS compression standard.
Non-Commercial Programs

HP Labs LOCO-I/JPEG-LS Home Page Rate
JPEG-LS is the new lossless/near-lossless compression standard for continuous-tone images developed by ISO/IEC JTC1/SC29/WG1 (final draft international standard FDIS14495-1 as of Novembr 1998). The standard is based on the LOCO-I algorithm (LOw COmplexity LOssless COmpression for Images) developed at Hewlett-Packard Laboratories
Update: The HP site has just added a JPEG-LS plugin for Photoshop, in addition to the HP implementation that has been there for some time.
LOCO-I/JPEG-LS Software Download Page Rate
HP offers some free JPEG-LS software, including a Windows DLL, PhotoShop plugin, and reference executables good on several platforms, including Windows, Linux, Solaris, and of course, HP-UX.
One anonymous reader dissed the package with this comment: Not particularly user friendly.
JPEG-LS Software Rate by David A. Clunie. A preliminary implementation of JPEG-LS.
Papers/Documentation

HP Labs LOCO-I/JPEG-LS Home Page Rate
JPEG-LS is the new lossless/near-lossless compression standard for continuous-tone images developed by ISO/IEC JTC1/SC29/WG1 (final draft international standard FDIS14495-1 as of Novembr 1998). The standard is based on the LOCO-I algorithm (LOw COmplexity LOssless COmpression for Images) developed at Hewlett-Packard Laboratories
Update: The HP site has just added a JPEG-LS plugin for Photoshop, in addition to the HP implementation that has been there for some time.
Signal Processing and Multimedia Group – Univ. of British Columbia Rate
Software for H.263, JPEG-LS, and JBIG-2. Follow the links to Software. Many publications as well.
Home site of the JPEG and JBIG committees Rate
As it says, this is the home site of the committees. You need to be a member to access some areas, but there is plenty of information here for the common man as well.
An Algorithmic Study on Lossless Image Compression Rate
by Xiaolin Wu, University of Western Ontario. A paper on the CALIC algorithm, first presented at DCC 96. This file is in PS format.
Robert Estes Rate
Robert Estes (UCDavis – image compression research). Robert has pointers to many of his papers on this page. He has info on Wavelet-based image compression, image compression, plus some peripherally related topics such as image quality.
Source Code

Signal Processing and Multimedia Group – Univ. of British Columbia Rate
Software for H.263, JPEG-LS, and JBIG-2. Follow the links to Software. Many publications as well.
Lossless JPEG Codec Rate
A freely redistributable lossless JPEG codec. Encoder, decoder, man pages, full C source, and some documentation.
Standards

FCD 14495 – public draft Rate
A final draft of the JPEG-LS document. This is not the standard, but it is bound to be pretty close. The doc says:
This document is the final committee draft of CD 14495, Lossless and near-lossless coding of continuous tone still images (JPEG-LS) agreed by ISO/IEC JTC1/SC29 to be made available for public comment on WG1 web site, www.jpeg.org.
HP Labs LOCO-I/JPEG-LS Home Page Rate
JPEG-LS is the new lossless/near-lossless compression standard for continuous-tone images developed by ISO/IEC JTC1/SC29/WG1 (final draft international standard FDIS14495-1 as of Novembr 1998). The standard is based on the LOCO-I algorithm (LOw COmplexity LOssless COmpression for Images) developed at Hewlett-Packard Laboratories
Update: The HP site has just added a JPEG-LS plugin for Photoshop, in addition to the HP implementation that has been there for some time.
Home site of the JPEG and JBIG committees Rate
As it says, this is the home site of the committees. You need to be a member to access some areas, but there is plenty of information here for the common man as well.
Return to The DataCompression.info home page
Copyright © 2000-2002, Mark Nelson, All Rights Reserved.
Copyright © 2005 Visicron Corp. All rights reserved.
Hit count:
Sponsored by Visicron
LHA

LHA is an archiver that was written in Japan in the 1980s. LHA was incredibly influential, forming the basis for dozens of archivers based on its source code.
DCL reader Joe S. points out that the archivers in the LHA family are one of the few archivers that have been supported and seen use on Amiga systems. He credits this to the hard work of one Stefan Boberg.

[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Commercial Libraries

TCompLHA component set Rate A Delphi component. TCompLHA helps you create and manage archives compatible with the popular freeware LHArc and LHA utilities (these archives can also be processed by the popular WinZip program if you have LHA). Simple one-step methods such as Scan, Compress, Expand, Delete and Verify make archive management very easy. In addition it includes the TSegLHA component which allows for the creation of segmented (e.g. multi-disk) archives.
Japanese Language Resources

Micco’s Home Page Rate
Home of LHMelt, UNLHA32.DLL, UNARJ32.DLL. All text on this page is in Japanese, except for a single link pointing to English information on UNLHA32.DLL.
DropLHA for Mac OS/X Rate A site that has a port of a drag and drop version of LHA to Mac OS X. My Japanese referrer tells me this version does not support MacBinary so resource forks will be lost by this program.
MacLHA support Rate This web site is run by the author of MacLHA, a drag and drop version of LHA for Mac OS. You can also get access to a drag and drop LHA expander for Mac OS here.
LHA Source code site Rate FTP site that contains LHA source code. Most of this page is in Japanese.
Links

LHA Compression Rate This page has a good set of pointers to LHA programs and source code, including variants such as AR002, lz_comp2, and Lharc.
Newsgroup Posts

LHA History Lesson Rate A few notes about the ancient history of LHA on comp.compression.
Non-Commercial Libraries

Micco’s Home Page Rate
Home of LHMelt, UNLHA32.DLL, UNARJ32.DLL. All text on this page is in Japanese, except for a single link pointing to English information on UNLHA32.DLL.
LHA Library for Java Rate jLHA is a Java library that supports reading and writing of LHA archives. It attempts to use the same interface as the java.util.zip package. It looks like there was a burst of activity in the spring of 2002, not much activity since them.
Huffman Compression Engine Rate This program is currently capable of reading and extracting files made with LHA and other utilities that generate .lzh files, from -lh4- to -lh7-. The foundation of the algorithm for this program like ARJ is based on Haruhiko Okumura’s work on ar002, which was the foundation of LHA. Unlike Haruhiko’s work however, the dictionary size is dynamic and currently allows for dictionary sizes of up to 64KB. On larger files, compression of files is usually 0.5% to 5% tighter than PKzip, and work in progress will likely yield even better results. Files created with this utility natively create -lh7- signed archives, which on larger files results in slightly better compression than that of lha32 by Haruyasu Yoshizaki.
Non-Commercial Programs

Micco’s Home Page Rate
Home of LHMelt, UNLHA32.DLL, UNARJ32.DLL. All text on this page is in Japanese, except for a single link pointing to English information on UNLHA32.DLL.
LHA Compression Rate This page has a good set of pointers to LHA programs and source code, including variants such as AR002, lz_comp2, and Lharc.
DropLHA for Mac OS/X Rate A site that has a port of a drag and drop version of LHA to Mac OS X. My Japanese referrer tells me this version does not support MacBinary so resource forks will be lost by this program.
MacLHA support Rate This web site is run by the author of MacLHA, a drag and drop version of LHA for Mac OS. You can also get access to a drag and drop LHA expander for Mac OS here.
Results

LHZ Benchmark Rate A set of benchmark results that compare various versions of LHA and jLHA. (jLHA is an LHA library found on the same web site.)
Source Code

LHA Compression Rate This page has a good set of pointers to LHA programs and source code, including variants such as AR002, lz_comp2, and Lharc.
LHA Library for Java Rate jLHA is a Java library that supports reading and writing of LHA archives. It attempts to use the same interface as the java.util.zip package. It looks like there was a burst of activity in the spring of 2002, not much activity since them.
LHA Source code site Rate FTP site that contains LHA source code. Most of this page is in Japanese.
Standards

LHA Notes Rate Nice detailed documentation on the structure of an LHA file. If you’re going to attempt to support LHA files, you need a pointer to this doc.
Tutorials, Reference, Presentations

LHA Notes Rate Nice detailed documentation on the structure of an LHA file. If you’re going to attempt to support LHA files, you need a pointer to this doc.
Return to The DataCompression.info home page
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Links

Pages of web links.
Archiving

Common Archives Library Project Rate
Home page for the Common Archivers Library project. This page is completely in Japanese, but an English version of the index is available at a single click. The goal of this project appears to be to provide standard library software that works with any and all archives. Good idea.
RAR 2.70 Rate
This site appears to have a massive number of links to the current versions of RAR. The entire site is written in Dutch.
Yahoo UNIX Archiving Links Rate Yahoo links to UNIX archiving software sources.
Archivers.8m.com Rate This site promises to deliver links and copes of every archiver know to man, along with news, polls, and more. The usual disclaimer apologizes for not being quite there due to a recent change in management.
Amiga compression formats Rate A good resource for anyone using compression or writing compression code for the Amiga platform. Includes tutorial and background information as well as links to code.
Archivers to download Rate A big list of pointers to archive programs for the Amiga platform.
Arithmetic Coding

Arithmetic Coding Rate The NIST page on arithmetic coding from their Dictionary of Algorithms and Data Structures. A terse definition and a couple of links.
Audio

StreamingMediaLand.com Portal site labels itself as a place with Resources for Engineers, Researchers, and Marketing People in the Streaming Media Field. The Knowledge Base has a good selection of links to standards, tutorials, code, etc. of interest to compression aficionados.
AudioCodingWiki Rate
A nice set of links to AudioCoding information. Since this is a Wiki site, it is highly collaborative – registered users can provide updates and modifications to the site at will. (I think.)
Lossless Compression of Audio Rate
My particular interest is in delivery of music via the Net – with compression which does not affect the sound quality at all. I am primarily interested in compression ratios, not speed of the programs. I think this is the first web site devoted to listing all known lossless audio compression algorithms and software – please email your suggestions and I will try to keep it up-to-date.
A comparison of Internet audio compression formats Rate
A good comparsion chart showing the relative merits of various audio formats. Includes links to definitions and other support information for each format.
MPEG Audio Resources and Software Rate
Links to lots of info regarding the audio compression portions of the MPEG standards. This includes an overview, the MPEG Audio FAQ, pointers to resources, some free software, and test bitstreams.
Audio Signal Processing Software Rate
Includes editing software, file formats and converters, codecs, and links. This page is at the University of Hannover, Germany. While there appears to be a wealth of software on this site, it would appear that you need special privileges to get access to ti.
ASF vs. MP3 vs. RA-G2 vs. VQF Rate
A comparison of various lossy audio compression schemes. Panos Stokas provides his take on the whole situation, and includes tons of links to files, articles, and more food for thought. Most readers seem to like this web page, but one reader had this negative comment: This website is patently and fatally flawed to the nth degree. Nothing but misconception and conjecture with no real basis in scientific analysis. Very misleading to the uneducated in audio compression.. Another reader says Just reading “However, we have not found a single implementation that did not produce serious amounts of distortion in our testing sample. Nobody seems interested any longer.” about AAC of all things, makes it apparent that this guy has no idea what he’s talking about or what he’s doing.
VQF.COM Rate This web site is dedicated to the support of VQF, a new audio compression format.
Compression Codecs Rate This site has a nice collection of codecs, including DirectShow filters, MPG4, MJPEG, and other video codecs. A few audio codecs and AVI test sequences as well.
The CWI Audio File Formats Guide Rate Useful links to information describing audio file formats.
Apple’s AAC Site Rate QuickTime 6 was an early adopter of MPEG-4 technology, and they seem to be big believers in the standard. This is in contrast to Microsoft’s Windows Media 9, which uses proprietary codecs to compete with the open standards of MPEG-4. The MPEG-4 standard uses AAC for encoding audio, and Apple has a site with a few links and information about this audio encoder. Alas, they don’t have a date when AAC will be included in the iPod!
Rarewares Rate A nice collection of pointers and links to audio/music compression software.
ReallyRareWares Rate From the launch:
Hello, and be welcome to ReallyRareWares, a site for researchers (or nostalgic people like me) that miss the old days of multimedia encoding. Here you’ll find reviews and history of old software (encoders and decoders), deceased codecs (VQF, ePAC), oddities (AUPECg2, Astrid AAC), and so on, as well as downloads.
Audio File Format FAQ Rate This FAQ provides good information about various audio file formats, which naturally includes quite a few compressed formats. It also has a few links to other relevant pages.
Backup

Delphi Programming – Backup and Data Compression Rate The About.com guide to Delphi Programming has a section on Data Compression and Backup software that looks pretty useful. About.com is a search engine and link site that features pages edited and maintained by real live humans.
Benchmarks

The Art Of Lossless Data Compression Rate
A comprehensive set of tests on lossless data compression.
Benchmark Images and Files Rate David Cary is a major link farmer. One of the sections of his massive Data Compression page has links to various images and files that are used in various benchmarks.
Burrows-Wheeler Transform/Block Sorting

Burrows-Wheeler Transformation / Block Sorting (BWT) Jürgen Abel has done an enormous amount of research on the Burrows-Wheeler Transform, and has published the results on his web site. On this page you will find:
A summary of this compression technique.
Links to over 70 online papers.
Links to at least that many people involved in BWT research or development.
Extensive links to BWT source code.
This web page may now be the definitive source of information for this field.
The Sort Transformation by Michael Schindler Rate Michael Schindler’s page describing a sorting algorithm that was presented in a poster session at DCC ’97. Links to his source code, plus links to the paper and poster in postscript format. Update: Michael has made additional source code available.
Michael Walden’s Compression Pointers Rate A comprehensive set of compression pointers. Unfortunately, Michael is using some sort of software that makes bookmarking into his index impossible. So instead, you must link to the main page, shown here, and locate the links to “Data Compression”. Under that he has links to General Resources, Software, and Theory.
Coding

Prefix Code Rate The definition from the NIST Dictionary of Algorithms and Data Structures.
Complexity

Kolmogorov Complexity Rate The definition from the NIST Dictionary of Algorithms and Data Structures.
Data Compression

BitJazz Compression Software Links The folks at BitJazz maintain a nice list of links to data compression directories. That makes this page sort of a meta-directory.
Mitsuharu ARIMURA’s Bookmarks on Source Coding/Data Compression Rate
An enormous page of data compression links, well organized by type. Although this page is hosted in Japan, nearly all of the links are described in English.
David Pereira Coutinho Rate
Personal page of David Pereira Coutinho, Professor at Instituto Superior de Engenharia de Lisboa. This page contains links to several compression-related abstracts and papers, as well as links to the Data Compression Framework developed with his students. (Indexed here as The DCG Framework.) The majority of the page is available in English and Portuguese.
Data Compression Site Rate
This site is in Russian, so I am not able to tell you much about it. It has links to some papers, and seems to have a link to PDF files that comprise much of a book on compression.
Reader Dan L. says The best site about comression!
Markus F.X.J. Oberhumer: Data Compresson Links Rate
Just what it says. A massive set of links.
AOL.COM search: Home > Computers > Algorithms > Compression Rate
The compression algorithms page under AOL.COM’s search engine.
David Cary’s Data Compression Links Rate
A huge number of links, thoughts, and documentation on a wide variety of data compression topics.
The Green Tree Of Compression Methods Rate
A Practical Introduction To Data Compression by Alexander Ratushnyak. A Data Compression mini-FAQ with a good set of links.
Data-compression.com Rate
The title says A website devoted to the principles and practices of data compression. Can’t ask for anything better than that. Appears to be run by Nam Phamdo from SUNY Stony Brook. Links to papers, explanations, and software.
User comment:Gives technical explanations and animated examples of a small number of compression methods. The explanations are good, but the amount of coverage of the field overall is small.
Maxime Zakharov – Compression Links Rate
Compression links to papers and web sites, mostly in Russian language.
Data Compression – Definition in the PC Webopedia Rate
The definition also has links to some keyword definitions.
Secção de Análise de Sinais Rate
A set of links that includes a few data compression sites. This page is from Instituto Superior de Engenharia de Lisboa (a Lisbon Polytechnic school), Portugal, and is in Portuguese. This page contains a link to the Data Compression Group object oriented framework for teaching C++. (Indexed here as The DCG Framework.
Compression des images (et autres documents) Rate
This site has pointers to various sits related to image compression. The entire site is written in French.
Welcome to ItComputing Online Research and Development Resources Rate
A page of links, with a substantial number dedicated to data compression.
Yahoo links to compression companies Rate
Links to companies engaging in commerce related to data compression. A moderate-sized set of links. At last check, in addition to direct listings, contains subtress for Commercial Products, Fractal Compression, and a couple of others.
Information Theory Research Group Rate
Home page for John C. Kieffer, Dept. of EE, University of Minnesota. Includes course descriptions for classes on data compression and information theory. The course descriptions have links to some papers.
Free Compression and Archiving Libraries and Source Code Rate
This web site keeps links to free libraries and source code. If you like this, you might want to browse around in some of their other areas as well.
DataCompression.info user Andrew S. was not too impressed with this site: I tried one half of their links and they were all dead or directed to content not related to the topic.
Yahoo links to compression Rate
A suprisingly sparse set of entries. You would think Yahoo could do better.
Sam’s Compression Links Rate A short list of assorted compression links, no particular theme.
AltaVista Compression Links Rate A page of compression links from AltaVista
Bibliography on Source Coding/Data Compression Rate Mitsuharu Arimura’s page of links and references to a wide variety of papers and books on lossless compression. Some of the links are listed in English, others in Japanese.
Lycos – Computers/Algorithms/Compression/ Rate A page of links on the Lycos portal.
Pin-Outs Algorithms : Compression Rate This portal site has a page dedicated to compression, plus a number of sub-pages with pointers to companies, researchers, and a few other odds and ends.
Theory of Data Compression Rate A nice overview of the field by Nam Phamdo, slanted a bit towards the academic view but at a very accessible level. Links to important and influential papers.
Dr. Sandra Woolley’s Data Compression Linkes Rate An assortment of links on a wide variety of compression related topics. Includes a rating system indicating the value of the links.
UCSB Signal Compression Lab Rate Various research areas of some interest in here.
Data Compression Pointers Rate A set of data compression links maintained by Haruhiko Okumura. Many of the links here point to Japanese language sites. Even if you cannot read Japanese, you may still profit from the profusion of links on this page. Just be sure your browser is set to render Shift-JIS.
The Compression Site Rate by Dave Kristula. Has download pages for archivers, plus benchmark results.
The Edge – Archives Rate A huge disordered collection of links, newsgroup posts, and random conversations regarding data compression.
Compression Algorithms Rate A set of links from Softpanorama, the Open Source Software Educational Society. A lot of information on the entire site. The compression links are not as complete, but some interesting stuff here.
What’s New In Math – October, 2002 – Compression Codes and Technologies Rate The American Mathematical Society runs a monthly column called ‘What’s New In Math,” featuring topics of general interest to their readers. In October 2002, the topic was data compression, which led to a fairly lengthy column with many, many references. Good reading!
AG Information und Komplexität Rate A nice set of links to various resources related to info theory and data compression. German language.
Algorithms in the Real World (Guy Blelloch) Rate Guy has a set of slides here that must illustrate a comprehensive set of links about data compression. Includes a link to a PS file containing a sample chapter on algorithms that Guy is writing.
Data Compression Benchmark Suite Rate A set of links to files that are used to benchmark various data compression algorithms.
EE 5585: Data Compression Rate A collection of class notes and links for a University of Minnesota course on Data Compression.
Google’s Data Compression Algorithm Directory Rate A selection of pointers to web sites that have something to do with data compression algorithms.
Mathtools.net DSP/Applications/Compression Page Rate Mathtools.net describes itself as the technical computing portal for all your scientific and computing needs. Perhaps a bit ambitious! Here’s their page links to compression applications.
Open Here Compression Algorithms Page Rate The Open Here search engine page dedicate to compression algorithms
Delphi Programming – Backup and Data Compression Rate The About.com guide to Delphi Programming has a section on Data Compression and Backup software that looks pretty useful. About.com is a search engine and link site that features pages edited and maintained by real live humans.
CiteSeer Compression References Rate CiteSeer tracks references between academic papers, and has links to online versions of a great many papers. The compression links at the top level look like they are a bit sloppy, but there are subcategories for Audio, Text, and Video, which look as though they may be better.
Oingo’s Compression Algorithms Page Rate Oingo is a human-edited directory, sort of a super-duper search engine.
Michael Walden’s Compression Pointers Rate A comprehensive set of compression pointers. Unfortunately, Michael is using some sort of software that makes bookmarking into his index impossible. So instead, you must link to the main page, shown here, and locate the links to “Data Compression”. Under that he has links to General Resources, Software, and Theory.
Esoterica/Miscellany

One to One Compression This site discusses a characteristic of some compression algorithms that the author refers to as One to One compression. In a nutshell, this property means that for any file X, F( F'( X ) ) == X. (F is either the compressor or decompressor, and F’ is its opposite number.) This is definitely not the case for most conventional compression algorithms.
Pattern Matching Pointers Rate
A really nice set of links to people and resources related to pattern matching. This is a great general purpose page of links, but only lightly grazes the data compression world.
Cognition as Compression Rate
Cognition as Compression, by Gerry Wolff, discussion of the author’s research.
From as long ago as the last century it has been recognised that information processing in brains and nervous systems (perception, learning, thinking, neuro-muscular control etc) may be governed by principles of economy or compression.

Cyclic Redundancy Check Rate
The definition from the NIST Dictionary of Algorithms and Data Structures.
3DCompression.com Rate A directory of links and resources on compressing the 3D models used for computer graphics and other large geometric datasets. This is a replacement for the site at http://www.cc.gatech.edu/~kingd/3Dcompression.html.
Mathtools.net – C/C++ Random Numbers Rate Links to code and tools to create random numbers. Quite useful, and includes some intriguing use of sound cards to provide true (instead of psuedo-random) numbers. Registration required.
Fractals

Yuval Fisher’s Fractal Links Rate
A very comprehensive page of links from Yuval Fisher, who is right there in the middle of the whole fractal business. This page features a glut of links to papers, bibliographies, books, conferences, and software. You can’t go wrong here.
Waterloo Fractal Compression Project Rate
The Waterloo Fractal Compression Project is part of a general research programme dedicated to the study of fractal analysis and Iterated Function Systems/Fractal Transforms from both theoretical as well as practical perspectives.
Waterloo Fractal Compression Project Rate
The Waterloo Fractal Compression Project is part of a general research programme dedicated to the study of fractal analysis and Iterated Function Systems/Fractal Transforms from both theoretical as well as practical perspectives
Vladimir Valenta’s Home Page Rate
Vladimir has pointers to a batch of his papers here, which seem to concentrate on image compression, including VQ and Wavelet based compression. Plus many links to image compression, fractal, and wavelet pages.
Compression des images (et autres documents) Rate
This site has pointers to various sits related to image compression. The entire site is written in French.
Signal and Image Processing Group Rate The University of Bath has a group that is advertised as “world leaders in still image and video coding.” They appear to be interested in lossy compression based on DCT, Wavelets, and Fractal compression. This is their home page.
Fractal Image Compression Bibliography Rate This bibliography was compiled from a number of sources, including the extensive bibliographies (in postscript form) by John Kominek and by Dietmar Saupe and Raouf Hamzaoui.
Fractal Compression Rate A giant bibliography with pointer to on-line papers, as well as some basic information on the state of the art. Not for the timid or the beginner.
Spanky Fractal Database Rate A database of Fractal resources.
GIF – Compuserve’s Graphics Interchange Format

Web Graphics Rate A tutorial page discussing the various image formats currently in use on the web. Nice comparisons and a good set of links.
Working with GIF images in Delphi Rate A straightforward article with some discussion and links.
Huffman Coding

One to One Compression This site discusses a characteristic of some compression algorithms that the author refers to as One to One compression. In a nutshell, this property means that for any file X, F( F'( X ) ) == X. (F is either the compressor or decompressor, and F’ is its opposite number.) This is definitely not the case for most conventional compression algorithms.
Shannon-Fano Coding Rate
The definition from the NIST Dictionary of Algorithms and Data Structures.
K-ary Huffman Encoding Rate The definition from the NIST Dictionary of Algorithms and Data Structures.
Image Compression

The Art Of Lossless Data Compression Rate
A comprehensive set of tests on lossless data compression.
Image Compression with Set Partitioning in Hierarchical Trees Rate
Welcome to the WWW home page that describes Set Partitioning in Hierarchical Trees (SPIHT): the powerful new wavelet-based image compression method.
Vladimir Valenta’s Home Page Rate
Vladimir has pointers to a batch of his papers here, which seem to concentrate on image compression, including VQ and Wavelet based compression. Plus many links to image compression, fractal, and wavelet pages.
Compression des images (et autres documents) Rate
This site has pointers to various sits related to image compression. The entire site is written in French.
David Clunie’s Medical Image Format Site Rate
David Clunie is the chair of the DICOM standards committee, and has a wealth of links on this page to information related to medical imaging.
Image Compression Research Rate A page devoted to image compression research at the University of Joensuu, which would appear to be in Finland. Links to more research and a PhD thesis.
Medical Image Format FAQ – Part 7 Rate Lots of pointers here. Relevant to compression because of the wealth of pointers to various formats used in medical imaging, such as JPEG-LS and Lossless JPEG.
Compression with Reversible Embedded Wavelets Rate CREW is a compression algorithm developed by RICOH that has been offered up to the JPEG working group as a potential standard. This page contains a description of the algorithms, along with samples and related documents.
3DCompression.com Rate A directory of links and resources on compressing the 3D models used for computer graphics and other large geometric datasets. This is a replacement for the site at http://www.cc.gatech.edu/~kingd/3Dcompression.html.
The DICOM Standard Rate This page gives a short introduction to the DICOM standard, commonly used for medical imaging. It has a lengthy set of links to DICOM viewers, images, and other resources.
Compression Research Rate This page contains information and links which are small a sampling of compression research that has been performed using the Lena image.
Binary Tree Predictive Coding Rate John Robinson’s page on BTPC, which includes documentation, samples, links, and source. BTPC is designed to do both lossy and lossless compression of images.
John updated this package to version 5 in March, 2003.
Avideh Zakhor’s Home Page Rate Avideh Zakhor has links to many of her papers on image compression.
Information Theory

Mitsuharu ARIMURA’s Bookmarks on Source Coding/Data Compression Rate
An enormous page of data compression links, well organized by type. Although this page is hosted in Japan, nearly all of the links are described in English.
University of Washington Data Compression Laboratory Rate
Current research projects in our lab include research into vector quantization (VQ), wavelets, image compression, edge detection using VQ, VQ for image browsing, VQ design for noisy channels, halftoning, and color palette management.
Entropy-Related Software Rate
Links to software, organized into three categories: Tutorials, Freeware, and Payware. Organized by Chris Hillman.
The Green Tree Of Compression Methods Rate
A Practical Introduction To Data Compression by Alexander Ratushnyak. A Data Compression mini-FAQ with a good set of links.
Information Theory Research Group Rate
Home page for John C. Kieffer, Dept. of EE, University of Minnesota. Includes course descriptions for classes on data compression and information theory. The course descriptions have links to some papers.
Information Theory, Pattern Recognition and Neural Networks Rate
Some sort of class outline, including lots of links and references.
Entropy in Information and Coding Theory Rate Like all of Chris Hillman’s pages, a nice set of links.
Gerry Wolf’s home page, Rate Gerry Wolf’s home page, including links to “Language Learning as Compression”, “Computing as Compression”, and “Cognition as Compression”
Entropy on the World Wide Web Rate Chris Hillman’s page of links to Information Theory pages, papers, etc.
Entropy on the web Rate Describe as Some resources of information theory and entropy concepts on the Internet.
Incompressible String Rate The definition from the NIST Dictionary of Algorithms and Data Structures.
AG Information und Komplexität Rate A nice set of links to various resources related to info theory and data compression. German language.
Internet

Webcompression.org Rate This site is dedicated to discussion and explanation of HTTP compression with the Apache web server. Looks to me like the first place to go for information.
JBIG

The JBIG Home Page Rate
Home page for the members of the JBIG committee, as well as a place for links and information about the Bi-Level Image coding standard.
Medical Image Format FAQ – Part 7 Rate Lots of pointers here. Relevant to compression because of the wealth of pointers to various formats used in medical imaging, such as JPEG-LS and Lossless JPEG.
The DICOM Standard Rate This page gives a short introduction to the DICOM standard, commonly used for medical imaging. It has a lengthy set of links to DICOM viewers, images, and other resources.
JPEG

Signal and Image Processing Group Rate The University of Bath has a group that is advertised as “world leaders in still image and video coding.” They appear to be interested in lossy compression based on DCT, Wavelets, and Fractal compression. This is their home page.
Web Graphics Rate A tutorial page discussing the various image formats currently in use on the web. Nice comparisons and a good set of links.
Guido’s Tech Corner Rate Guido Vollbeding has posted a number of items related to the IGJ code. Includes ways to crop, rotate, and merge JPEG files.
JPEG – Information Links Rate A page of links from the JPEG committee.
JPEG-2000

JasPer: A Software-Based JPEG-2000 Codec Implementation Rate
Jasper is a C-language implementation of the JPEG-2000 Part-1 standard. Michael Adams seems to run the show, with help from Image Power and a small team. This page gives you access to the software, documentation, and a nice set of links. Jasper is distributed under a free license.
Version 1.701.0 is shipping as of February, 2004.
JPEG 2000 Tools 2.0 Rate
Developed in the scope of MIGRATOR 2000 project (www.migrator2000.org), this site presents a graphical user interface to the three currently available codecs (VM, JJ2000, Jasper) as well as validation and parsing services to J2k codestreams and JP2 files. It’s currently a widely used tool within WG1 (JPEG) to perform compliance tests on coders and codestreams. Site requires free registration for purposes of tracking stored images.
Viper – The JPEG 2000 Resource Page Rate
A page of links and information from the image processing folks at Purdue.
JPEG 2000 – Links to Information Rate The JPEG 2000 committee uses this as the main source of links to the JPEG 2000-related pages on their site. It also includes a friendly plug for a book by committee members, with a “Buy Me” link to Amazon.com.
JPEG – Information Links Rate A page of links from the JPEG committee.
JPEG-LS

Medical Image Format FAQ – Part 7 Rate Lots of pointers here. Relevant to compression because of the wealth of pointers to various formats used in medical imaging, such as JPEG-LS and Lossless JPEG.
LHA

LHA Compression Rate This page has a good set of pointers to LHA programs and source code, including variants such as AR002, lz_comp2, and Lharc.
Lossless Compression

Context Tree Weighting Context Tree Weighting (CTW) has been a technique with great promise, but it hasn’t ever been able to reach the critical mass needed to become more than a curiousity. Jürgen Abel is doing his best to overcome that problem. He’s created a nice reference page for CTW on his data-compression.info web site. He has references to a few papers, a few people, and one piece of source code.
The Art Of Lossless Data Compression Rate
A comprehensive set of tests on lossless data compression.
Compression Basics by Pasi ‘Albert’ Ojala Rate
An introductory paper. Includes information on Huffman coding, Info Theory, Coding, LZ77, LZ78, and more. This page also has a good set of links.
Lossless Compression of Audio Rate
My particular interest is in delivery of music via the Net – with compression which does not affect the sound quality at all. I am primarily interested in compression ratios, not speed of the programs. I think this is the first web site devoted to listing all known lossless audio compression algorithms and software – please email your suggestions and I will try to keep it up-to-date.
Lossless Data Compression Rate
An overview of the topic by Nam Phamdo, with some basic definitions, plus a look at Huffman coding and LZ78/LZW coding.
David Clunie’s Medical Image Format Site Rate
David Clunie is the chair of the DICOM standards committee, and has a wealth of links on this page to information related to medical imaging.
Data Compression Links from Epsilon Coder Rate Links that mostly point to some papers and source code, concentrating on lossless LZ type compression.
Websites: Lossless Compression Rate Links to various lossless compression sites. Inlcudes a few things off the beaten path.
The DICOM Standard Rate This page gives a short introduction to the DICOM standard, commonly used for medical imaging. It has a lengthy set of links to DICOM viewers, images, and other resources.
Lossy Compression

Signal and Image Processing Group Rate The University of Bath has a group that is advertised as “world leaders in still image and video coding.” They appear to be interested in lossy compression based on DCT, Wavelets, and Fractal compression. This is their home page.
LZO

LZOP Binary Download Site Rate
The author created this site to make LZOP readily available. The page has links to download binaries, plus links to other LZO and LZOP sites.
LZ78/LZW and derivatives

Lempel-Ziv Welch – NIST Reference Page Rate The National Insitute of Standards and Techology reference page on LZW compression. Pointers to an explanation, implementation, and more information.
MP3/MPEG Audio

MP3Tech.org Rate
This site is dedicated to the MP3 standard. You will find here information about the MP3 standard and upcoming audio compression techniques, tests, MPEG source code.
MPEG Audio Programmer’s corner Rate
MP3′ Tech calls this “the biggest MPEG audio source codes area avaible on the Internet.” Find source for MPEG-1/2/2.5 Layer 1/2/3, MPEG-2 AAC and MPEG-4, as well as UI code.
Reader Robert S. said It seems very hard to find a description of the Layer 3 bitstream format. Fimally found it here.
askMP3 – The MP3 Portal Rate
MP3.ORG has clustered a bunch of MP3 resources in one location. This is a page of links, links, and more links. If you can’t find a link to what you need here, it probably isn’t an MP3 question.
MPEG Audio Resources and Software Rate
Links to lots of info regarding the audio compression portions of the MPEG standards. This includes an overview, the MPEG Audio FAQ, pointers to resources, some free software, and test bitstreams.
ASF vs. MP3 vs. RA-G2 vs. VQF Rate
A comparison of various lossy audio compression schemes. Panos Stokas provides his take on the whole situation, and includes tons of links to files, articles, and more food for thought. Most readers seem to like this web page, but one reader had this negative comment: This website is patently and fatally flawed to the nth degree. Nothing but misconception and conjecture with no real basis in scientific analysis. Very misleading to the uneducated in audio compression.. Another reader says Just reading “However, we have not found a single implementation that did not produce serious amounts of distortion in our testing sample. Nobody seems interested any longer.” about AAC of all things, makes it apparent that this guy has no idea what he’s talking about or what he’s doing.
Jocsoft – MP3 For Developers Rate Jocsoft makes some software products used for searching the web, and one of those is designed to search for MP3 files. As a result, they decided to include a nice page of MP3 links for developers on their web page. It’s a little dated, with a high ratio of dead links, but still worth a look if you’re an MP3 afficionado.
MPEG

Structured Audio Online Rate
Apparently the MPEG4 specification includes an option for an audio format called “Structured Audio”, which seems to be a MIDI-like way to create sound files.
Berkeley MPEG Tools Distribution Rate
Berkely supplies a complete distribution of MPEG tools that have been widely ported and are used in many MPEG applications. The toolset includes and MPEG-1 video encoder and decoder, along with some analysis and content creation software. This page also has links to some adidtional information and a few MPEG sample files.
It would appear that this is freeware, but I have not yet verified this.

MPEG Audio Public Documents Rate
A big batch of pointers to various MPEG documents. Includes press releases and docs on MPEG-2, MPEG-4, MPEG-7, and AAC.
MPEG Audio Resources and Software Rate
Links to lots of info regarding the audio compression portions of the MPEG standards. This includes an overview, the MPEG Audio FAQ, pointers to resources, some free software, and test bitstreams.
MPEG Starting Points and FAQs Rate A really great resource for those seeking MPEG information. Pointers to lots of fundamental information, FAQs, and answers to many questions.
Compression Codecs Rate This site has a nice collection of codecs, including DirectShow filters, MPG4, MJPEG, and other video codecs. A few audio codecs and AVI test sequences as well.
JP’s Wavelet Compression Page Rate A recent post to comp.compression had a pointer to this page, identifying it as a source of H.263 software. Sure enough, if you scroll down to the bottom of the page you’ll find links to an H.263 decoder, plus a Windows H.263 player. Not to mention some Wavelet code from JP, and a few other interesting links.
MPEG-4 Industry Forum Resources Link Rate Links to scads of papers, web sites, software, etc., all related to the MPEG-4 standard.
Image Communication Group JVT Page Rate A series of links to various pieces of the Joint Video Team effort, including links to the working drafts of the H.264 standard.
MPEG-2 Digital Video Rate A big batch of links related to MPEG and Digital Video.
PNG

AOL.COM search: Home > Computers > Data Formats > Graphics > 2D > PNG Rate
AOL’s search page dedicated to the PNG format
Browsers with PNG support Rate
A list of browsers that support PNG. I’m not sure if this information is as relevant as it once was.
Portable Network Graphics – PNG Rate
The PNG project home page. If you want source code, information, or links relating to the PNG compressed image format, this is the place.
Miscellaneous Applications with PNG Support Rate
Miscellaneous apps with PNG support
News and History of the PNG Development Group Rate
What’s going on with PNG? Inquiring minds want to know! Note that this page includes links to the history pages for previous years, currently 1995-1998
Current Status of PNG Rate
Want to know how things are going in the world of PNG? Come check this page from time to time. See the current ratings for Stability, User Acceptance, Application Support, and so on.
Applications with PNG Support Rate
Just what it says.
Other PNG Links and Stuff Rate
Lots of links to PNG related material
Image editors with PNG support Rate This page has a really big batch of links to editors that have PNG support. The links to the individual editors haven’t been added to the database, so this page should be considered to be the master source.
Web Graphics Rate A tutorial page discussing the various image formats currently in use on the web. Nice comparisons and a good set of links.
PNG-Tech: Technical Issues regarding the PNG File Format Rate This site contains a collection of comments, impressions, comparisons, experiments and ideas regarding the PNG (Portable Network Graphics) file format, and related technologies: zlib (Data Compression Library), and MNG (Multiple-image Network Graphics). It is focused especially on the compression algorithms used in PNG.
PPM

PPM FAQ Rate What appears to be a comprehensive FAQ on PPM programming. Russian language, and fairly slow loading, but no reason not to try Google or BabelFish for a translation.
Dmitry Shkarin Rate Dmitry Shkarin is the author of the PPMD compressor. His homepage has links to to versions A-I of the compressor as of April, 2003. This page is in Russian, but I find that running it through BabelFish produces a usuable translation.
Quantization

University of Washington Data Compression Laboratory Rate
Current research projects in our lab include research into vector quantization (VQ), wavelets, image compression, edge detection using VQ, VQ for image browsing, VQ design for noisy channels, halftoning, and color palette management.
Vector Quantization Rate
A short description of VQ by Nam Phamdo. Contains an animation which provides a nice picture of what actually happens in VQ.
Vladimir Valenta’s Home Page Rate
Vladimir has pointers to a batch of his papers here, which seem to concentrate on image compression, including VQ and Wavelet based compression. Plus many links to image compression, fractal, and wavelet pages.
Speech

Cysip DSP Courses Rate
These folks offer some seminars on communcations. On their page, if you go to the links to free software, you will find Matlab code for CELP and LPC Vocoders. This same page also has a wide variety of links for speech coding stuff.
AudioCodingWiki Rate
A nice set of links to AudioCoding information. Since this is a Wiki site, it is highly collaborative – registered users can provide updates and modifications to the site at will. (I think.)
comp.speech WWW site Rate
This site contains the comp.speech FAQ, and also has links to their ftp site, which contains software for speech codecs.
Speech Compression Rate
A page on speech compression by Nam Phamd. Concentrates on LPC and CELP.
GSM 06.10 lossy speech compression Rate
GSM provides telephone quality speech at a compressed rate of 13 Kbps. Compare this to the 64 KBps required by standard u-law and A-law codes. This site gives lots of info about the GSM format, along with free source code.
Suffix Trees

Suffix Tree Rate
The definition from the NIST Dictionary of Algorithms and Data Structures.
Jesper Larsson’s Research Links Rate I am a graduate student (doktorand) in algorithms and data structures at the Department of Computer Science at Lund University. Special interests are text searching and data compression. I use the links on this page to papers, but don’t index the page itself
Suffix Array Rate The definition from the NIST Dictionary of Algorithms and Data Structures.
Video

StreamingMediaLand.com Portal site labels itself as a place with Resources for Engineers, Researchers, and Marketing People in the Streaming Media Field. The Knowledge Base has a good selection of links to standards, tutorials, code, etc. of interest to compression aficionados.
Advanced Multimedia Processing Lab Rate
This lab at CMU seems to be doing some interesting things with video compression. At a minimum, they have an H.263 codec you can download.
http://www.ganesh.org/related/video.html Rate A page of links to Video Compression pages. Good set of links, including pointers to test sequences.
Compression Codecs Rate This site has a nice collection of codecs, including DirectShow filters, MPG4, MJPEG, and other video codecs. A few audio codecs and AVI test sequences as well.
JP’s Wavelet Compression Page Rate A recent post to comp.compression had a pointer to this page, identifying it as a source of H.263 software. Sure enough, if you scroll down to the bottom of the page you’ll find links to an H.263 decoder, plus a Windows H.263 player. Not to mention some Wavelet code from JP, and a few other interesting links.
A Review of Video Streaming over the Internet Rate A technical report giving an overview of various video streaming formats used in today’s Internt. Includes low-level details such as transport formats, and high-level info such as providers of application servers.
The AVI Graphics Format Overview Rate Anything and everything you ever wanted to know about AVI format files.
vcodex links page Rate A set of links to various video coding resources, maintained by Iain Richardson, author of “”Video Codec Design.”
Wavelets

AOL.COM search: Home > Science > Math > Wavelets Rate
The AOL.COM search page devoted to Wavelets.
A brief guide to wavelet sources Rate
S. Baum at Texas A&M keeps up a pretty good looking page of links to wavelet resources, categorized by type. Note that this page has apparently been zipped up to save space. The full content is inside the gz file.
University of Washington Data Compression Laboratory Rate
Current research projects in our lab include research into vector quantization (VQ), wavelets, image compression, edge detection using VQ, VQ for image browsing, VQ design for noisy channels, halftoning, and color palette management.
Amara’s Wavelet Page Rate
A lot of explanation of Wavelets on this page, along with some well-considered links. This site is often slow, and sometimes missing. Please be patient!
Image Compression with Set Partitioning in Hierarchical Trees Rate
Welcome to the WWW home page that describes Set Partitioning in Hierarchical Trees (SPIHT): the powerful new wavelet-based image compression method.
Wavelets and Signal Processing Rate
Ian Kaplan’s Wavelet and Signal Processing page has lots of articles and C++/Java source code implementing wavelet transform via the lifting scheme, the integer-to-integer wavelet transform and the best basis wavelet packet transform
Vladimir Valenta’s Home Page Rate
Vladimir has pointers to a batch of his papers here, which seem to concentrate on image compression, including VQ and Wavelet based compression. Plus many links to image compression, fractal, and wavelet pages.
Wavelet Resources – Yale Rate
Links from the Yale Computational Mathematics Group. Contains links to software and papers. Most of the links don’t show up in this database as they are not necessarily related to using wavelets for data compression.The papers that appear off this page are all compressed postscript and have not been added to the database.
Wavelets Rate A big collection of links to Wavelet resources on the Web from Andreas Uhl.
Signal and Image Processing Group Rate The University of Bath has a group that is advertised as “world leaders in still image and video coding.” They appear to be interested in lossy compression based on DCT, Wavelets, and Fractal compression. This is their home page.
Wavelet Resources from Mathsoft Rate This page has references to a huge number of Wavelet-related research papers. I don’t know how many of them are online, but it is quite a treasure trove for the curious.
Surfing the Wavelets Rate A nice on-line paper that proposes to teach you a little something about wavelets.
The Discovering Wavelets Web Page Rate Grand Valley State University page providing undergraduate resources for learning about wavelets.
JP’s Wavelet Compression Page Rate A recent post to comp.compression had a pointer to this page, identifying it as a source of H.263 software. Sure enough, if you scroll down to the bottom of the page you’ll find links to an H.263 decoder, plus a Windows H.263 player. Not to mention some Wavelet code from JP, and a few other interesting links.
Wavelets for Motion and Video Coding Rate A bibliography containing links to numerous papers on video coding, with links to authors as well. This is a chapter from the massive Annotated Computer Vision Bibliography.
Washington University Wavelet Netcare Rate Yet another Web page full of links to wavelet resources.
Filip Rooms Rate Filip is interested in wavelets and image restoration. In addition to a nice page of links (navigate from the main page) he has some software, publications, test results, and more.
Zip

ZIP archive file format Rate Marco Schmidt has assembled a nice page of links and information on the Zip archive format. A few good links, but this isn’t the comprehensive guide you need to answer any question about the format.
zlib

zlib information Rate
Some information and assorted links regarding zlib.
Webcompression.org Rate This site is dedicated to discussion and explanation of HTTP compression with the Apache web server. Looks to me like the first place to go for information.
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Lossless Compression

This category covers lossless compression methods that can’t be pinned down to one of the more refined topics, such as LZW or Zip. In some cases, the items here are esoteric algorithms that don’t’ merit their own topics. In other cases, they span one or more existing topics. The unifying theme is of course that they are lossless. This means that after compressing and then decompressing, the data set in quesition will be bit-for-bit identical.
[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Books

Universal Compression and Retrieval Rate
By Rafail Krichevsky, Institute of Mathematics, Russian Academy of Sciences, Novosibirsk University, Russia. This volume constitutes a comprehensive self-contained course on source encoding.
Please use this link to purchase the book through Amazon.com. Your purchase will help support this web site.
Reader Yuriy R. says: A concise and rigorous course on universal source coding and universal information retrieval. Only suitable for math. oriented readers, graduate students, and researchers in these fields. Engineers expecting to find source-code of data compression algorithms shall look elsewhere.
Commercial Libraries

DC Micro Home page for DC Micro, home of Crusher!, the data compression toolkit
Xceed Streaming Compression Library The Xceed Streaming Compression Library is a high-performance “raw” compression library. It offers the ability to compress and decompress streaming data, buffers, strings or single files and supports multiple compressed data formats. Unlike the Xceed Zip Compression Library, this ultralight library doesn’t offer Zip file handling capabilities.
Xceed Streaming Compression for .NET Xceed Streaming Compression for .NET is an efficient and lightweight data compression class library for Microsoft .NET and ASP.NET. It can process any size byte array with ease and provides a true .NET pass-through stream object for automatically compressing or decompressing any .NET stream’s data on the fly. It supports the GZip, Zlib, Deflate and Deflate64 compression formats.
Xceed Zip for .NET Compact Framework Xceed Zip for .NET Compact Framework is a data compression and all-purpose file manipulation class library for creating mobile apps. It provides flexible zip, gzip and streaming data compression capabilities for compact applications created with Visual Studio .NET 2003. The library includes an innovative and extensible filesystem object model that makes zip files as easy to work with as regular files or folders.
Hi/fn, Inc. Rate
Hi/fn makes lossless compression hardware and software. They have a bunch of chips that implement LZS and MPCC compression, plus a library that does the same thing. I have been led to believe that these algorithms are partially or completely protected by patents.
RICAZip.com Rate
RICAZip.com has proprietary lossless image compression technology called RICA (Reversible Image Compression Algorithm). RICA retains original file formats (e.g. TIFF, DICOM, BMP, TGA, PGM etc.). RICACom says We have yet to find any method that provides better compression ratios (for truly lossless), including wavelet. On a PII 450MHz RICA compresses @ 6MB per second and decompresses at 12MB per second.
Available as a standalone image archive app, Adobe Photoshop Plugin, Browser Plugin, and RICA SDK.
DCL reader Karen H. says: Evaluation of this product demonstates excellent compression ratios and it is also very fast compared to other methods I have used.
BitJazz Rate
A company that makes PhotoJazz, a lossless compression plug in package that they describe as having Breakthrough lossless photo-quality compression of stills and movies for archival, print, and the Internet. Version 2.0 supports Mac and Windows, Photoshop, QuickTime, and Quark. You can download the Reader for free and try it out.
EasyCompression Library for Delphi Rate EasyCompression Library is a TFileStream, TMemoryStream and other TStream descendants replacement to their analogues with transparent compression/decompression and encryption in the same stream. All the methods, properties and behavior of TFileStream and TMemoryStream are supported, so it is very simple to replace them in the application code. Key features: Forward and backward seeks in compressed stream; Read and write any portion of data at any file position; OnProgress event handler and compression rate indicator; Password protection provided by Rijndael encryption algorithm; Fastest compression level is extremally fast.
PICVideo Codec from Pegasus Imaging Rate This software codec produces video in three different formats: Motion JPEG, Wavelet 2000, and Lossless JPEG.
HTMLZip Rate HTMLZip is a utility to creating compressed HTML pages. True compression algorithm reduces files to 20%-70% of original. JavaScript is used for extracting in your browser (no third-party software).
Release 1.06 appears to have gone out in October, 2002.
Intelligent Compression Technologies Rate A company that speciailizes in providing compression technology to other companies.
Master Creative Software Rate Supplier of data comrpession libraries to use with FoxPro. Includes FOXSQZ, an archiving and compression library, COMP5, a compression library, and JavaSQZ, a data compression library for Java.
Commercial Programs

SoftDefender Rate
Soft Defender is a good exe file compressor, which can reduce the file size of 32-bit Windows programs by as much as 50%.In addition, Soft Defender is a perfect product of software protection of applications.With Soft Defender, your application can have anti-debugging, anti-tracer, anti-disassemble, anti-dumping, anti-apihook, file integrity checking functions in seconds. It requires no source code editing or your registration algorithm changing.
RICAZip.com Rate
RICAZip.com has proprietary lossless image compression technology called RICA (Reversible Image Compression Algorithm). RICA retains original file formats (e.g. TIFF, DICOM, BMP, TGA, PGM etc.). RICACom says We have yet to find any method that provides better compression ratios (for truly lossless), including wavelet. On a PII 450MHz RICA compresses @ 6MB per second and decompresses at 12MB per second.
Available as a standalone image archive app, Adobe Photoshop Plugin, Browser Plugin, and RICA SDK.
DCL reader Karen H. says: Evaluation of this product demonstates excellent compression ratios and it is also very fast compared to other methods I have used.
X-PRESS Rate
A Multiplatform data compression program, looks like it runs on a wide variety of IBM mini and mainframes. Company has a dual-language web site, with English and German language versions.
Telvox Software Shop Rate
This site has links to Telvox’s CODEC package, which appears to ship in both free and commercial versions. CODEC uses proprietary lossless compression, and is ported to a wide variety of platforms. Telvox is located in Bologna, Italy, and has duplicate web pages in English and Italian.
Data Compression Program for VM/ESA Rate
DATA COMPRESSION PROGRAM for VM/ESA enables VM customers to automatially (sic) and transparently compress and expand CMS minidisk file data. This capability can help reduce DASD utilization, load on the I/O subsystem, and staff time spent managing minidisk space and “disk full” conditions.
From your friends at IBM.

The Official daxaif Home Page Rate From the site: daxaif is a no-loss audio compression program which performs live capture or converts audio files, movie sound tracks, or audio CD tracks into a compressed “.dax” file format. This format allows fast locating and selection of audio passages through the use of a clickable compression-factor map. The selections can be played or saved in uncompressed AIFF or further compressed to AIFC format using any QuickTime-supported compresser. .
limes datentechnik® gmbh Rate These folks deliver a tool called FLAM which uses a patented data compression algorithm to do something. The site has English and German language versions, but doesn’t seem to have any detailed information on FLAM.
Solution-Soft Rate Solution-Soft is the provider of software for online archiving and for bandwidth management in the Internet infrastructure and the enterprise. Solution-Soft’s products enable data files to be archived online and transferred faster over networks through a revolutionary technology providing transparent compression and decompression.
MaX Compression Rate This product compresses email before transmission to save network bandwidth.
ServerZip Rate Stonebroom makes a product called ServerZip that compresses ASP web pages for quicker download.
GT Technology Rate This site advertises a bunch of nifty looking codecs, including TELP, JPEG, Speech, MPEG, and wavelet compressors. I can’t quite determine exactly what form the products come in.
PipeBoost Rate PipeBoost offers HTTP Compression software that comes with a big list of customers and testimonials. You can download a 30 day trial copy, so you have nothing to lose!
MoleBox Rate Pack all your files into a single executable with MoleBox or MoleBox Pro.
MediaZip Rate MediaZip is a Windows program that performs lossless compression/decompression and manages archives of media files (Sound and Picture). Welcome to the MediaZip home page.
BrowseBlast Web Accelerator Rate The press release says: Ikano and SlipStream launched the BrowseBlast Internet service for U.S. consumers. SlipStream’s Web Accelerator is supposed to increase connection speed significantly for dial-up and wireless connections. The software compresses Web content once it leaves the server, increasing browsing speeds to five times the traditional dial-up or wireless speed.
Companies/Organizations

DC Micro Home page for DC Micro, home of Crusher!, the data compression toolkit
RICAZip.com Rate
RICAZip.com has proprietary lossless image compression technology called RICA (Reversible Image Compression Algorithm). RICA retains original file formats (e.g. TIFF, DICOM, BMP, TGA, PGM etc.). RICACom says We have yet to find any method that provides better compression ratios (for truly lossless), including wavelet. On a PII 450MHz RICA compresses @ 6MB per second and decompresses at 12MB per second.
Available as a standalone image archive app, Adobe Photoshop Plugin, Browser Plugin, and RICA SDK.
DCL reader Karen H. says: Evaluation of this product demonstates excellent compression ratios and it is also very fast compared to other methods I have used.
Advanced Hardware Architectures Rate
Home page for Advanced Hardware Architectures. AHA makes a few different chips that implement various forms of lossless data compression.
DAKX LLC Home Page Rate DAKX is claiming a new method of lossless data compression that is fast and patented. It works on audio and video data. The method is called difference-adaptive compression. DAKX supplies a bit of source code that you can experiment with, and will be happy to license the technology to you or your company.
Data Compression Technology by Compris.com Rate These folks appear to be selling some lossless compression technology, but I’m not quite able to determine what it is.
Solution-Soft Rate Solution-Soft is the provider of software for online archiving and for bandwidth management in the Internet infrastructure and the enterprise. Solution-Soft’s products enable data files to be archived online and transferred faster over networks through a revolutionary technology providing transparent compression and decompression.
Intelligent Compression Technologies Rate A company that speciailizes in providing compression technology to other companies.
GT Technology Rate This site advertises a bunch of nifty looking codecs, including TELP, JPEG, Speech, MPEG, and wavelet compressors. I can’t quite determine exactly what form the products come in.
Geolytics Rate This company appears to be in the business of packaging demographic data for research and commercial interests. As part of that, they apparently have some technology for performing some compression on the data sets.
GEMAC Rate This company sells an IP core that performs lossless data compression. Not sure what algorithm they are using, it is described as “GEMAC’s data compression algorithm.” This algorithm was first published at DCC ’95, and is described as a hybrid of ZL1 and ZL2, created with the goal of maximizing compression rate.
QuikCat Technologies Rate These guys use compression to increase messaging throughput on your network. Looks like they work with Microsoft Exchange, as well as having a general purpose product for ISPs.
Files

CCITT standard fax images Rate
TIFF versions of the CCITT images.
German

X-PRESS Rate
A Multiplatform data compression program, looks like it runs on a wide variety of IBM mini and mainframes. Company has a dual-language web site, with English and German language versions.
Reversible Kompressionsalgorithmen Rate
What appears to be a discussion of Lossless compression algorithms, including Huffman coding, Arithmetic Coding, LZW, LZSS, and LZH.
limes datentechnik® gmbh Rate These folks deliver a tool called FLAM which uses a patented data compression algorithm to do something. The site has English and German language versions, but doesn’t seem to have any detailed information on FLAM.
GEMAC Rate This company sells an IP core that performs lossless data compression. Not sure what algorithm they are using, it is described as “GEMAC’s data compression algorithm.” This algorithm was first published at DCC ’95, and is described as a hybrid of ZL1 and ZL2, created with the goal of maximizing compression rate.
Hardware

Hi/fn, Inc. Rate
Hi/fn makes lossless compression hardware and software. They have a bunch of chips that implement LZS and MPCC compression, plus a library that does the same thing. I have been led to believe that these algorithms are partially or completely protected by patents.
DCP Research Rate
DCP’s unique compression algorithm, the GCA, achieves significantly higher compression ratios than Stac Electronics’ LZS–typically 20% to 80% better. This difference is only a total of tens to hundreds of dollars for storage situations, but it can save hundreds of dollars a month on a leased communication link.
Real-Time Lossless Compression Systems Rate
Some folks at Loughborough U. are working on attempts to integrate data compression more closely with computer hardware. This page has reports on their progress, as well as links to some of their papers.
X-Match Pro Rate A fast ASIC core designed for lossless compression.
Data compression technology in ASIC cores Rate A paper from the IBM R&D group discussing the use of lossless compression in hardware.
Parallel Implementation of Data Compression Technologies for Multi-Gbit/s Networks Rate This group at Loughborough University in the UK would like to use sophisticated compression techniques in high speed networks. To make it all happen, they need to do it in hardware, and do it in parallel. This page has information about their efforts, along with links to papers and other information.
IBM research breakthrough doubles computer memory Rate IBM has created a chip that appears to be able to dynamically compress data as it is being written to RAM. Details sketchy in this news release.
GEMAC Rate This company sells an IP core that performs lossless data compression. Not sure what algorithm they are using, it is described as “GEMAC’s data compression algorithm.” This algorithm was first published at DCC ’95, and is described as a hybrid of ZL1 and ZL2, created with the goal of maximizing compression rate.
SA-Comp/1 and SA-Comp/4 Data Compression SA Rate Cisco makes a box you can attach to their routers. The box performs lossless data compression.
Italian

Telvox Software Shop Rate
This site has links to Telvox’s CODEC package, which appears to ship in both free and commercial versions. CODEC uses proprietary lossless compression, and is ported to a wide variety of platforms. Telvox is located in Bologna, Italy, and has duplicate web pages in English and Italian.
Links

Context Tree Weighting Context Tree Weighting (CTW) has been a technique with great promise, but it hasn’t ever been able to reach the critical mass needed to become more than a curiousity. Jürgen Abel is doing his best to overcome that problem. He’s created a nice reference page for CTW on his data-compression.info web site. He has references to a few papers, a few people, and one piece of source code.
Lossless Compression of Audio Rate
My particular interest is in delivery of music via the Net – with compression which does not affect the sound quality at all. I am primarily interested in compression ratios, not speed of the programs. I think this is the first web site devoted to listing all known lossless audio compression algorithms and software – please email your suggestions and I will try to keep it up-to-date.
The Art Of Lossless Data Compression Rate
A comprehensive set of tests on lossless data compression.
Compression Basics by Pasi ‘Albert’ Ojala Rate
An introductory paper. Includes information on Huffman coding, Info Theory, Coding, LZ77, LZ78, and more. This page also has a good set of links.
Lossless Data Compression Rate
An overview of the topic by Nam Phamdo, with some basic definitions, plus a look at Huffman coding and LZ78/LZW coding.
David Clunie’s Medical Image Format Site Rate
David Clunie is the chair of the DICOM standards committee, and has a wealth of links on this page to information related to medical imaging.
Data Compression Links from Epsilon Coder Rate Links that mostly point to some papers and source code, concentrating on lossless LZ type compression.
Websites: Lossless Compression Rate Links to various lossless compression sites. Inlcudes a few things off the beaten path.
The DICOM Standard Rate This page gives a short introduction to the DICOM standard, commonly used for medical imaging. It has a lengthy set of links to DICOM viewers, images, and other resources.
Newsgroup Posts

What is the state of the art in lossless image compression? Rate
The comp.compression FAQ attempts to answer this question.
George Buynovsky’s Post on ACB Rate
ACB is poorly understood. The author, George Buynovsky, has only made a few public comments on the algorithm. This is one of them.
ACB Rate
A post from Leonid A. Broukhis discussing the mysterious ACB compressor by George Buynovksy.
Peter Fenwick’s LZP = BlockSort = Shannon Rate Part of a conversation between Peter Fenwick and Charles Bloom.
Non-Commercial Libraries

Lzip Rate
Lossy data compression which can reduce input files to 0% of their size. Hint: product was released April 1, 2000.
DCL reader Tim A. marvels: Wow! it’s even faster than tarring to /dev/null!
Charles Bloom’s binary executables Rate
Includes WaveVideo, PPMZ, LZP, and WaveCode. Charles has source for most of this stuff available elsewhere on his page.
The LPAC Homepage Rate
LPAC is a codec for lossless compression of 8, 12, 16, 20, and 24 bit audio files. It has cross-platform support for Windows, Linux and Solaris. Direct playback of LPAC files is possible with a Winamp plug-in. A satisfied user tells the DCL Compression on the material I use is superior to the FLAC encoder.
The UCL Compression Library Rate
UCL is a portable lossless data compression library written in ANSI C. This work is from Markus F.X.J. Oberhumer, known for LZO, UPX and more.
DataCompression.info reader Swift G. had this to say: Excellent library. The compression routines are fast and if you need binary compression this is the way to go.
UnicodeCompressor : another alphaworks technology Rate IBM has developed a pair of Java clases that compress Unicode according to the Standard Compression Scheme for Unicode. Looks like they might be giving it away here.
FLAC – Free Lossless Audio Coder Rate FLAC is an open-source project which specifies a lossless compressed audio format and provides an encoder, decoder, and several player plugins. Aside from yielding better compression than Shorten, the format supports sample-accurate seeking and many other features useful for streaming and archival.
Reader Colin B. says: Incredible lossless audio compression, depending on the source, of course. I have seen high-quality speech recordings compressed to 10% of the original size, losslessly..
FLAC 1.1.0 released in January, 2003. A good roster of new features for this coder, including updates for libraries and plugins.
PJL Compressing Filter Rate A J2EE servlet filter which compresses data written to the response. It supports several algorithms (gzip, deflate, etc.) and emphasizes minimal memory usage and high throughput. Also provides detailed performance stats.
SynCE – Dynamite Rate Dynamite is a tool and library for decompressing data compressed with PKWARE Data Compression Library and it was created from the specification provided by a post in the comp.compression newsgroup.
zisofs-tools Rate The zisofs filesystem is an extension to the ISO9660 filesystem that allows files, on a file-by-file basis, to be stored compressed and decompressed in real time. The zisofs filesystem is supported by recent versions of Linux (2.4.14 or later). Legacy systems can still read uncompressed files. zisofs-tools contains the tools necessary to create such a compressed ISO9660 filesystem and to read compressed files on a legacy system.
Java FLAC Codec Rate FLAC is a port of the Free Lossless Audio Codec (FLAC) library to Java. This library allows java developers to experiment and write programs that use the FLAC algorithms.
Version 0.5 is shipping as of June, 2004.
OptimFROG SDK Rate Florin Ghido has packaged his lossless compressor into a nice SDK – take advantage of his great audio compression in products of your own.
BitMagic Rate BitMagic is C++ library designed and developed to implement efficient platform independent bitsets, with the following key features:
Several types of on-the-fly adaptive compression.
Dynamic range of addressable space of 232 bits.
Efficient memory management.
Serialization in platform independent, compact format suitable for storing in files and databases.
Performance tuning for 32-bit and 64-bit systems.
Version 3.1.4 shipped August, 2003.
CodeProject: Compress Data Rate A new article on The CodeProject describing code to compress/decompress to/from an ISequentialStream interface. Code is supplied to implement this for Cfile and CByteArray. The compression itself is done via zlib. The rationale for this project is that the author needed cookbook code that worked with MFC objects.
libmspack – A library for Microsoft compression formats Rate A project whose goal is to implement libraries to support the various and sundry compression formats that Microsoft has cooked up over the years. Early in the process, much work left to be done.
MG4J: Managing Gigabytes for Javaâ„¢ Rate A Java implementation of the inverted-index compression systems described in the book Managing Gigaybtes. This GPLed effort doesn’t appear to have any connection with Witten, Moffat, or Bell.
Version 0.8.2 is shipping in October, 2003.
Non-Commercial Programs

DualStream – Near Lossless Audio Compression Rate
DualStream is aimed at filling the big gap between perceptual coding and lossless coding. The goal is to offer real transparent audio coding (not only perceptually transparent) at half or less the bitrate generally used by lossless coding, and also to permit progressive consistent increase of the quality level, until lossless coding is reached. To eliminate the problem of choosing between lossless and near lossless, DualStream has an option to create a correction file, which may be eventually stored separately and used at a later time to restore the original. The advantage is that the two files (near lossless and correction) have together approximately the size of the lossless coded original file.
Monkey’s Audio Rate
This is a lossless audio compression format that has support for WinAmp and Windows Media Player. Retain perfect fidelity for your music recordings, at the cost of additional disk space.
Version 3.99 is shipping as of May, 2004.
OptimFROG – IEEE Float Rate
A lossless compressor for audio data stored as IEEE floating point data.
OptimFROG – squeezing the bits out of audio Rate
OptimFROG is a lossless audio compressor. Lots of claims for great performance!
OptimFROG 4.507 is shipping as of October, 2003. Features added since my last report include numerous bug fixes and performance tweaks. The author claims to have superior lossless compression ratios, includes numerous player plugins, and is free for non-commercial use.
Version 4.507 is shipping as of October, 2003.
Charles Bloom’s binary executables Rate
Includes WaveVideo, PPMZ, LZP, and WaveCode. Charles has source for most of this stuff available elsewhere on his page.
TTA Lossless Audio Compressor Rate
A lossless codec developed in Russia originally for radio telescope data. Apparently that specialized codec turned out to be good on audio data as well. Distributed under a free license.
Vidfern Squeezer Rate
Squeezer is another executable compressor for Windows, and it’s now free. Here’s what you’ll read on the Vidfern web site:
Vidfern Squeezer as the best file compressor, can squeeze executable files as well as text and HTML files. Get more space by squeezing your files! Squeezer is now free for personal and commercial use. It is fully functional, easy and powerful.

Reader Vali from the jp TLD said Thanks to all who create this real good product. I found it a very nice and easy compressor that supports exe, html and text files freely!
The LPAC Homepage Rate
LPAC is a codec for lossless compression of 8, 12, 16, 20, and 24 bit audio files. It has cross-platform support for Windows, Linux and Solaris. Direct playback of LPAC files is possible with a Winamp plug-in. A satisfied user tells the DCL Compression on the material I use is superior to the FLAC encoder.
Hybrid Lossless Audio Compression Rate
WavPack allows you to losslessly compress (and restore) both 16 and 24-bit audio files in the .WAV format. Unlike “lossy” compression schemes (like MP3) that discard information, WavPack converts the audio data into a more compact form so that the restored files are digitally identical to the original source. It’s somewhat like the file compression portion of WinZIP except that it’s optimized for audio data. Like other lossless compression schemes the data reduction varies with the source, but it is generally between 25% and 50% for typical popular music and somewhat better than that for classical music and other sources with greater dynamic range.
(X)MedCon – Medical Image Conversion Utility Rate
A free program to deal with image formats in popular medical formats, including DICOM, SPM, PNG, and GIF.
Version 0.9.1 of (X)MedCon shipped in January, 2004.
Flexible Parsing (FP) – The Optimal Parsing for Dictionary Based Compression Rate
This page describes Flexible Parsing, a proposed extension for dictionary based compression schemes. Yossi Matias, Nasir Rajpoot, and Cenk Sahinalp have a summary of their work on this page, along with links to three PS format papers that go into detail on the results. The authors summarize this improved technique as “looking one step ahead for the longest phrase in the dictionary instead of trying to find the longest possible phrase at hand.”
BMF Rate
BMF program is lossless/near-lossless image compression utility. It supports true colour, high colour, greyscale and paletted images compression.
yabbawhap – Y and AP compression filters Rate
Public domain code by Daniel Bernstein. (Note that this ftp site has an excellent selection of compressoin programs and code.)
Telvox Software Shop Rate
This site has links to Telvox’s CODEC package, which appears to ship in both free and commercial versions. CODEC uses proprietary lossless compression, and is ported to a wide variety of platforms. Telvox is located in Bologna, Italy, and has duplicate web pages in English and Italian.
Bernie’s TMW0.51 Page Rate
The home page for TMW. TMW is a program for losslessly compressing greyscale images that gives world class compression ratios, at the cost of being tremendously CPU intensive. The current version is TMW_0.51, and is still completely experimental
Shorten Utilities (shnutils) Rate shnutils is a collection of 3 Perl scripts developed to assist in the process of using shorten to trade digital music. These scripts, which run on both Linux and Windows, facilitate compressing WAV files using shorten, and also in creating and verifying MD5 hashes.
Compressed Virtual Memory Rate Rodrigo Castro has an interesting project going at the University of Sao Paulo in Brasil. Rodrigo is integrating compression with the virtual memory system of Linux. By storing compressed pages in RAM, he hopes to improve overall system performance. The goal is to read and write fewer pages to disk. See the full details on his project page at SourceForge.
M5 Online Compression Utility ver 1.0.1 Rate The University of Central Florida has this web page which allows you to upload a file and then compress it using a wide variety of algorithms.
FLAC – Free Lossless Audio Coder Rate FLAC is an open-source project which specifies a lossless compressed audio format and provides an encoder, decoder, and several player plugins. Aside from yielding better compression than Shorten, the format supports sample-accurate seeking and many other features useful for streaming and archival.
Reader Colin B. says: Incredible lossless audio compression, depending on the source, of course. I have seen high-quality speech recordings compressed to 10% of the original size, losslessly..
FLAC 1.1.0 released in January, 2003. A good roster of new features for this coder, including updates for libraries and plugins.
PackWord Rate PackWord can compress a Microsoft Word document (.doc) file into a smaller, compressed, .doc file. The compressed .doc file is self-extracting: when loaded into Microsoft Word, the compressed document will automatically expand to the original version.
Eri32 High Performance Freeware Multimedia Archiver Rate This web page shows a set of images that the author uses to demonstrate the performance of the Eri compressor. The claim is that Eri32 does better on these 24 bit color images than any other lossless compressor.
waRmZip Rate This is a Win32 script that can be used to compress and/or delete files after a certain amount of time. Nice and simple.
Version 1.2 shipped in January, 2004.
Stuns Rate This program tries to unpack the given file by application of several algorithms byte-by-byte. Result of work of the program is the set of files with the unpacked data. Many of the produced files are not correct. However, among them there can be correctly unpacked data. Correctly unpacked files have mainly significant sizes that distinguishes them from dust.
axPAQ Rate A compressor built with the world-beating PAQAR 3.0 compressor. axPAQ wraps a GUI around the engine, and includes complete source.
FlacPack – Free lossless instrument file compression Rate This project aims to define a standard for the lossless compression of MIDI patch files. From the title, you might guess that the lossless audio compression is performed using FLAC – other binary data is compressed w/zlib.
Malcom Taylor’s Home Page Rate This link takes you to Malcom’s RKAU program, a lossless audio compressor. Malcom’s page says it often beats WA in max mode, at double the speed.
PDF Compress Rate Free PDF Compressor that removes duplicate PDF objects, optionally takes advantage of new compression features of latest PDF specification (1.5), and optionally takes advantage of a new proposed format called “Compact PDF” that for many classes of documents compresses 30 – 60% better than what is possible in PDF 1.5.
Note: Navigate up two levels to get to Tom’s download page.
Version 2.2 is shipping as of February, 2004.
M99 Rate This page is devoted to a new compressor called M99. The author says that M99 is a new type of statistical compressor that has speeds rivaling the fastest Huffman coders with ratios of the best statistical modeling programs. Good!
Linux File System Compression Rate This open source package, e2compr, provides transparent compression and decompression of Linux ext2 file systems.
Version 0.4.44 is shipping as of April, 2004.
GrepMail Rate This nifty program searches through a normal or compressed mailbox looking for strings. Supports Gzip, Bzip2, and tzip formats.
SONARC: Digital Audio Compression, Version 2.1i Rate SONARC is an old DOS audio compression program that was apparently used in Ultima, a well known game.
Papers/Documentation

Context Tree Weighting Context Tree Weighting (CTW) has been a technique with great promise, but it hasn’t ever been able to reach the critical mass needed to become more than a curiousity. Jürgen Abel is doing his best to overcome that problem. He’s created a nice reference page for CTW on his data-compression.info web site. He has references to a few papers, a few people, and one piece of source code.
Text Preprocessing for Data Compression by Jürgen Abel and William Teahan. This paper looks at a few different techniques for preprocessing data before performing text compression, and compares the gains achieved when combining the preprocessors with PPM, BWT, and LZ algorithms.
Xmill – An Efficient Compressor for XML Rate
Those folks at AT&T have developed a compressor that can be used to squeeze individual data items in XML documents. AT&T says this is “essentially free” software. Read the license on-line to determine exactly what that means.
Xmill paper Rate
A technical paper describing the principles behind Xmill, the AT&T package that compresses XML data items.
Symbol Ranking Text Compression with Shannon Recodings Rate
by Peter Fenwick, Department of Computer Science, The University of Auckland.
In his work on the information content of English text in 1951, Shannon described a method of recoding the input text, a technique which has apparently lain dormant for the ensuing 45 years. Whereas traditional compressors exploit symbol frequencies and symbol contexts, Shannon’s method adds the concept of “symbol ranking”, as in `the next symbol is the one third most likely in the present context’.

Lossless Compression of 3D MRI Brain Images Rate
Typical clinical MRI scanners generate data on the order of about 200 MB each day. Because this data provides important diagnostic information, care must be taken in compressing it, and lossy compression is generally avoided. In this project we investigate different techniques for lossless compression of 3-dimensional MRI scans of the brain. These methods include predictive coding, “model coding” using a reference data set, background suppression, symmetry coding and pyramid coding
Matlab source code is included along with the full text of the paper.

Flexible Parsing (FP) – The Optimal Parsing for Dictionary Based Compression Rate
This page describes Flexible Parsing, a proposed extension for dictionary based compression schemes. Yossi Matias, Nasir Rajpoot, and Cenk Sahinalp have a summary of their work on this page, along with links to three PS format papers that go into detail on the results. The authors summarize this improved technique as “looking one step ahead for the longest phrase in the dictionary instead of trying to find the longest possible phrase at hand.”
Real-Time Lossless Compression Systems Rate
Some folks at Loughborough U. are working on attempts to integrate data compression more closely with computer hardware. This page has reports on their progress, as well as links to some of their papers.
The Design and Analysis of Efficient Lossless Data Compression Systems Rate
Our thesis is that high compression efficiency for text and images can be obtained by using sophisticated statistical compression techniques, and that greatly increased speed can be achieved at only a small cost in compression efficiency.
Complete paper is included in PS format.

Reversible Kompressionsalgorithmen Rate
What appears to be a discussion of Lossless compression algorithms, including Huffman coding, Arithmetic Coding, LZW, LZSS, and LZH.
TIFF Software Rate
A collection of free TIFF software. This may help you decode files in TIFF format. Includes some documentation files.
The Context Tree Weighting Method: Basic Properties Rate One page poster for Frans M.J. Willems, Yuri M. Shtarkov, and Tjalling J. Tjalkens, “The Context Tree Weighting Method: Basic Properties,” IEEE Trans. Inform. Theory, May 1995. (Postscript)
Code and Parse Trees for Lossless Source Encoding Rate A survey paper by Julia Abrahams.
Context Weighting for General Finite-Context Sources, Rate by Frans M.J. Willems, Yuri M. Shtarkov, and Tjalling J. Tjalkens, IEEE Trans. Inform. Theory, Sept. 1996. A postscript version of this overview paper.
Universal Source Encoding for Science Data Rate NASA says that this data compression algorithm is the Government Invention of the year. It is apparently an algorithm that can be used by spacecraft with limited transmission bandwidith.
Publications of Wojciech Szpankowski Rate A good selection of papers online relating to pattern matching and compression.
Hirosuke Yamamoto’s Papers Rate This page has links to online versions of Hirosuke Yamamoto’s papers on data compression. Papers here on block sorting, coding, and more. The papers are all published in English.
Lossless Compression of Grayscale Medical Images – Effectiveness of Traditional and State of the Art Approaches Rate The very long title of this PDF format paper pretty much obviates the need for any more description on my part.
The MLP Lossless Compression System Rate A paper that details the lossless compression system used in DVD-Audio.
Estimating entropy rates with Bayesian confidence intervals Rate I’m pleased to announce with my co-authors availability of a preprint on our new algorithm to estimate the Shannon entropy rate (bits/symbol) or (bits/sec) of an observed sequence of low-alphabet symbols. It uses the Context-Tree-Weighting universal compression method, but doesnot use the compression ratio directly as an entropy estimator but as a scaffold for a Bayesian estimate. The result is significantly lower bias.
R. Nigel Horspool — On-Line Publications Rate The compression-related papers seem to concentrate on LZ and other lossless methods.
Craig Nevill-Manning Rate Links to several publications related to data compression and pattern matching.
Home Page of Martin Cohn Rate Martin Cohn’s home page contains links to several of his compression papers, which seem to be concentrated on lossless compression issues.
Performance as a function of compression Rate This IBM research paper looks into the performance of compressors in relation to the compressibility of the the objects they are compressing. At least I think that’s what it is talkinga bout.
Data compression technology in ASIC cores Rate A paper from the IBM R&D group discussing the use of lossless compression in hardware.
A fast hardware data compression algorithm and some algorithmic extensions Rate A paper by D.J. Craft discussing findings from some research on lossless compression algorithm.s
Off-Line – Data Compression by Textual Substitution Rate A novel algorithm by Stefano Lonardi. It recursively replaces words in text with pointers, and boasts of good results. Source and papers regarding Off-Line can all be found here.
Algorithms for Triangulated Terrains Rate by Marc van Kreveld. This paper looks at a method for compressing geographical elevation data.
Sequitir – inferring hierarchies from sequences Rate SEQUITUR is a method for inferring compositional hierarchies from strings. It detects repetition and factors it out of the string by forming rules in a grammar. The rules can be composed of non-terminals, giving rise to a hierarchy. It is useful for recognizing lexical structure in strings, and excels at very long sequences.
Parallel Implementation of Data Compression Technologies for Multi-Gbit/s Networks Rate This group at Loughborough University in the UK would like to use sophisticated compression techniques in high speed networks. To make it all happen, they need to do it in hardware, and do it in parallel. This page has information about their efforts, along with links to papers and other information.
Error Modeling for Hierarchical Lossless Image Compression Rate by P.G> Howard and J.S. Vitter. This paper from DCC ’92 describes an improved method for error modeling in hierarchical lossless image compression.
Text Compression via Alphabet Re-representation Rate by P. M. Long, A. I. Natsev, and J. S. Vitter, from DCC ’97.
A Bit-Wise Adaptable Entropy Coding Technique Rate This paper describes an entropy encoder that can outperform Huffman or arithmetic coding.
Prefix Compression of Sparse Binary Strings Rate by David Salomon. This article discusses an approach to the unique problem of compression sparse binary strings.
The Benefits and Drawbacks of HTTP Compression Rate A paper by Timothy McLaughlin that gives an overview of HTTP Compression and tries to decide whether it’s a good thing for not.
People

Context Tree Weighting Context Tree Weighting (CTW) has been a technique with great promise, but it hasn’t ever been able to reach the critical mass needed to become more than a curiousity. Jürgen Abel is doing his best to overcome that problem. He’s created a nice reference page for CTW on his data-compression.info web site. He has references to a few papers, a few people, and one piece of source code.
The $5000 Compression Challenge Rate
Patrick Craig has an interesting tale to tell. Without being a data compression expert, he managed to beat the $5000 compression challenge. You won’t see him taking an ocean cruise with his winnings, though. DCL reader commented: The challenge was obviously met.
Peter Fenwick. Rate
Dr. Peter Fenwick’s home page. Fenwick has links to several of his compression papers on this page, including several recent papers discussing BWT algorithms.
Ross Williams Rate
Ross Williams did some seminal work in the area of dictionary based encoders in the late 1980s and early 1990s. His LZRW algorithms were not only innovative and interesting, but they managed to place Ross right in the middle of some early software patent issues.
Portuguese

The DCG Framework Rate
DCG Framework is a object oriented framework for lossless data compression. It is written in C++, and intends to be a didactic framework for data compression teaching. This framework is pointed to by the Secção de Análise de Sinais page.
Results

Maximum Compression Rate
Werner Bergmans has created a new benchmark site that aims to show the best compression ratios possible for multiple file types, including English text, executables, graphics, and so on. Werner says he is running these tests with 80-100 programs for each file type!
Reader Werner B. says Useful site to compare results of different compression programs. Regularly updated.
Berto’s Compression Spreadsheet Rate
Comparisions of over 230 archivers, in handy Excel format, from Berto.
Reader Emiliano C. said “Wonderful! Great! Wonderful! Cool!”
Lossless Compression of Audio Rate
My particular interest is in delivery of music via the Net – with compression which does not affect the sound quality at all. I am primarily interested in compression ratios, not speed of the programs. I think this is the first web site devoted to listing all known lossless audio compression algorithms and software – please email your suggestions and I will try to keep it up-to-date.
The Art Of Lossless Data Compression Rate
A comprehensive set of tests on lossless data compression.
Russian

Compression and Encryption Sources Rate Links to a variety of lossless coders, includes source for Huffman, arithmetic, LZSS, and other compressors.
Source Code

Xmill – An Efficient Compressor for XML Rate
Those folks at AT&T have developed a compressor that can be used to squeeze individual data items in XML documents. AT&T says this is “essentially free” software. Read the license on-line to determine exactly what that means.
Lossless Compression of 3D MRI Brain Images Rate
Typical clinical MRI scanners generate data on the order of about 200 MB each day. Because this data provides important diagnostic information, care must be taken in compressing it, and lossy compression is generally avoided. In this project we investigate different techniques for lossless compression of 3-dimensional MRI scans of the brain. These methods include predictive coding, “model coding” using a reference data set, background suppression, symmetry coding and pyramid coding
Matlab source code is included along with the full text of the paper.

Statistical Coders Rate
A group of statistical coders from Charles Bloom. This includes several different entropy encoders, including Huffman, Adaptive Huffman, CACM Arithmetic coding, and a Skew Coder.
The DCG Framework Rate
DCG Framework is a object oriented framework for lossless data compression. It is written in C++, and intends to be a didactic framework for data compression teaching. This framework is pointed to by the Secção de Análise de Sinais page.
Dictionary Coders Rate
This page has links to the source code for a family of compressors written by Charles Bloom. This includes the LZP family, an LZW example, LZRW, and LZCB.
TIFF Software Rate
A collection of free TIFF software. This may help you decode files in TIFF format. Includes some documentation files.
A Simple Yet Highly Efficient Compressing Technique Rate A nice CodeGuru article describing compression of a dictionary.
Stuns Rate This program tries to unpack the given file by application of several algorithms byte-by-byte. Result of work of the program is the set of files with the unpacked data. Many of the produced files are not correct. However, among them there can be correctly unpacked data. Correctly unpacked files have mainly significant sizes that distinguishes them from dust.
axPAQ Rate A compressor built with the world-beating PAQAR 3.0 compressor. axPAQ wraps a GUI around the engine, and includes complete source.
Random Access Data Compression Rate Source code from Random Access Data Compression, by Philip Gage (see gage.zip) from the Septeber 1997 C User’s Journal
Comrpession Algorithms Rate Arkadi Kagan has created a C++ project that implements a batch of our favorite lossless algorithms, including LZ77, LZ78, LZW, RLE, along with arithmetic and Huffman coding.
Version 1.1 shipped in April, 2004.
Compression and Encryption Sources Rate Links to a variety of lossless coders, includes source for Huffman, arithmetic, LZSS, and other compressors.
Off-Line – Data Compression by Textual Substitution Rate A novel algorithm by Stefano Lonardi. It recursively replaces words in text with pointers, and boasts of good results. Source and papers regarding Off-Line can all be found here.
Sequitir – inferring hierarchies from sequences Rate SEQUITUR is a method for inferring compositional hierarchies from strings. It detects repetition and factors it out of the string by forming rules in a grammar. The rules can be composed of non-terminals, giving rise to a hierarchy. It is useful for recognizing lexical structure in strings, and excels at very long sequences.
Standards

CCITT standard fax images Rate
TIFF versions of the CCITT images.
ITU V.44 Standard Adopted Rate
The ITU has officially adopted the v.44 standard, which is starting to ship in mid-2001 on modems supporting the v.92 standard. V.44 uses a compression algorithm known as LZJH, which was invented by Jeff Heath and is owned by Hughes Network Systems. According to Jeff, ITU testing showed that V.44 was 20% to 60% better than V.42bis on typical internet web downloads.
Standard ECMA-321 Streaming Lossless Data Compression Algorithm (SLDC) Rate A standard.
Standard ECMA-222 Adaptive Lossless Data Compression Algorithm Rate This page has the standard publication that defines ECMA-222, which is also apparently known as ALDC. I don’t know where this standard is used.
rfc1661 – The Point To Point Protocol Rate The description of the point to point protocol, which of course includes a little tiny bit on compression, since you can specify compression in a packet header.
Recommendation for Space Data Systems Standards Rate This appears to be the Data Compression Blue Book published by the Consultative Committee for Space Data Systems. It’s a nice document, but I’m not sure if the standard described here is actually in use. As is so often the case with standards documents, I find myself yearning for some accompanying reference code. Alas, there is none that I know of.
Note: a related document discussing performance characteristics of the recommendate can be found here
Cisco V.44 Press Release Rate Cisco talks a bit about new products using V.44 compression licensed from Hughes Network Systems. A few claims, not much in the way of facts.
Tutorials, Reference, Presentations

Range coder Arturo Campos describes a version of arithmetic coding which renormalizes in bytes, thus achiving twice the speed of an standard implementation and 0.01% less compression.
Quasi Static model Arturo Campos describes a model for arithmetic coding which results in less compression than an adaptative one, but at much higher speeds.
ACB, DMC, PPM, LZ – Classification, Idea, Comparision Rate
by George Buyanovsky. One of the only existing explanations of the mysterious ACB algorithm.
Data Compression Rate
An overview of the field by Debra A. Lelewer and Daniel S. Hirschberg. Lots of informative text. This appears to be a survey paper that was adapted for presentation on the web. Lossless compression techniques only!
Compression Basics by Pasi ‘Albert’ Ojala Rate
An introductory paper. Includes information on Huffman coding, Info Theory, Coding, LZ77, LZ78, and more. This page also has a good set of links.
Lossless Data Compression Rate
An overview of the topic by Nam Phamdo, with some basic definitions, plus a look at Huffman coding and LZ78/LZW coding.
Lossless Compression Algorithms (Entropy Encoding) Rate
An overview of the basics, including Shannon-Fano, Huffman, Arithmetic coding, and a section on LZW for good measure.
Aurora Borealis – a new way of compression Rate
This document describes the Aurora Borealis algorithm, which combines statistical analysis with a back end using an unknown type of coding. Author Michael Asse seems to have high hopes for this technique.
DataCompression.info reader Viktor F. had this to say: This compression method is inefficient. LZW can beat this easily. The author should read some books about compression.
Location Based Encoding – LBE Rate Chitaranjan P.S., Arun Shankar, and Niyant .K posted a description of a new coding scheme called LBE on the web. It’s interesting, but I’m not sure that it appears to have any serious advantages over current state of the art.
Metode rjecnika Rate A look at lossless compression techniques, including LZ77, LZSS, LZ78, and LZW. Croatian language.
The original of this page is now missing, any help locating it would be greatly appreciated. You can find an archived copy at the link.
LZRW4: Ziv and Lempel meet Markov Rate By Ross Williams, 1991. A description of a lossless algorithm invented by Ross Williams. The algorithm is based on LZW compression with the addition of a Markov-like prediction engine. Maybe.
A Simple Yet Highly Efficient Compressing Technique Rate A nice CodeGuru article describing compression of a dictionary.
Introduction to Data Compression Rate A set of slides, maybe to accompany a lecture. Covers basic info theory and data compression.
Introduction / Lossless Data Compression Rate A web page that provides an overview of lossless techniques.
Data Compression Rate by Jack Ganssle. A quick look at lossless compression, including RLE, Huffman coding, and LZ techniques.
The Golomb/Rice Image Compression Web Page Rate A senior project whose goal was to design a hardware compressor for continuous tone images. Contains a description of the algorithm, Matlab implementations, chip designs, and more.
The DICOM Standard Rate This page gives a short introduction to the DICOM standard, commonly used for medical imaging. It has a lengthy set of links to DICOM viewers, images, and other resources.
Technical Overview of Cartesian Perceptual Compression Rate This is a bi-level image compression scheme designed to be used for scanned images of books, faxes, etc. It is a non-degrading scheme, but not lossless. The company reports that their current customer list includes GetThePatent.com, FIS|Online, JSTOR, and Kurzweil. More information about clients and partners can be found here.
Japanese Lossless Video Codec Rate I’ll have to take the word of the submitter on this site – it is entirely written in Japanese. Any DataCompression.info user who is fluent in the language is invited to provide a more detailed description. There are a couple of zip files on the site that perhaps contain demo programs?
Compressed Postscript Documents – FAQ Rate A Technical Documentation bulleting from TI that answers the question “What is a Compressed Postscript (.psz) File?”
Bitmagic Hierarchical Compression Rate BitMagic is a C++ library that deals with dynamic bit vectors. It supports a couple of different ways to compress these bit vectors. This page explains how to perform common operations on bit vectors while they are compressed in memory.
What is D-Gap Compression? Rate BitMagic is a C++ library that deals with dynamic bit vectors. It supports a couple of different ways to compress these bit vectors. This page discusses D-Gap Compression.
Lossless Audio Compression Rate This document describes a lossless audio compressor that does some straightforward prediction in combination with a Rice coder. This is credited to Matt Ashland, author of the Monkey’s Audio codec.
performance: HTTP Compression Rate An article on the Mozilla web site that talks about improving perceived performance via HTTP compression. This article looks at implementation on the Apache server.
Unknown/Other Language

Metode rjecnika Rate A look at lossless compression techniques, including LZ77, LZSS, LZ78, and LZW. Croatian language.
The original of this page is now missing, any help locating it would be greatly appreciated. You can find an archived copy at the link.
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Lossy Compression

This category covers lossy compression methods that can’t be pinned down to one of the more refined topics, such as JPEG or MP3. In some cases, the items here are esoteric algorithms that don’t’ merit their own topics. In other cases, they span one or more existing topics. The unifying theme is of course that they are lossy. This means that after a compression/decompression cycle, the data set will be modified. Ideally, when compression image or sound files, the loss is either minimal or undetectable by human observors.
[ Deja News ] Search compression newsgroups for references to this topic
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Companies/Organizations

GeoEnergy, Inc. Rate Their home page advertises GeoEnergy as “The leader in fast data compression algorithms for the oil and gas industry.” Quite a few algorithms are listed, all of which work on various types of collected seismic data.
Signal and Image Processing Group Rate The University of Bath has a group that is advertised as “world leaders in still image and video coding.” They appear to be interested in lossy compression based on DCT, Wavelets, and Fractal compression. This is their home page.
Courses/Seminars

Multimedia Computing and Networking 2002 Rate The term “Multimedia” obviously covers a lot of different topics. Compression is one of them, and there is certainly a great deal to learn about compression and media formats at this conference.
German

Irreversible Kompressionsalgorithmen Rate A study of lossy compression algorithms, including discussion of JPEG, MPEG, and the DCT.
Links

Signal and Image Processing Group Rate The University of Bath has a group that is advertised as “world leaders in still image and video coding.” They appear to be interested in lossy compression based on DCT, Wavelets, and Fractal compression. This is their home page.
Papers/Documentation

Compression of Multimedia Information Rate
by A.Ratushnyak. A short discussion related to the compression of audio and pictures. A Russian version of the paper can be found at http://geocities.com/eri32/mmi.txt.
A Library readher had this to say: Worth reading 2 or 3 times.
Publications by Wil Osberger Rate Wil Osberger has published a bunch of papers dealing the perceptual image assessment. You can see most of them here. While this isn’t strictly a compression topic, it is obviously of critical importance to lossy compression techniques.
Irreversible Kompressionsalgorithmen Rate A study of lossy compression algorithms, including discussion of JPEG, MPEG, and the DCT.
Results

U of F Says Compressing Medical Images Risky Rate A study at the University of Florida showed that even mildly compressing coronary angiograms led to an increase in diagnostic errors.
Tutorials, Reference, Presentations

Wikipedia entry: Lossy Compression Rate This Wikipedia entry describes lossy data compression. In addition to a nice overview, includes links to many lossy compressors for still image, moving image, music and sound.
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LZO

LZO is an implementation of an algorithm designed for embedded systems that have tight memory or speed requirements. While it won’t compress as well as algorithms such as deflate, it will make up for that by its thrifty use of your computing resources.
[ Deja News ] Search compression newsgroups for references to this topic
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Files

LZO download site Rate The primary site for downloading LZO files. This includes mini-LZO, a shrunk down version of the LZO library, Perl-LZO, and Python-LZO.
Links

LZOP Binary Download Site Rate
The author created this site to make LZOP readily available. The page has links to download binaries, plus links to other LZO and LZOP sites.
Non-Commercial Libraries

The LZO home page. Rate
LZO is a compression library designed for real time projects that need fast compressors and decompressors. LZO is free under the GPL. Current release is LZO 1.07.
The UCL Compression Library Rate
UCL is a portable lossless data compression library written in ANSI C. This work is from Markus F.X.J. Oberhumer, known for LZO, UPX and more.
DataCompression.info reader Swift G. had this to say: Excellent library. The compression routines are fast and if you need binary compression this is the way to go.
Not Really Vanished Rate
The home page for NRV, the next generation successor to LZO. NRV is a portable lossless data compression library written in C++. It offers pretty fast compression and *very* fast decompression. Decompression requires no memory. NRV is free under the GPL.
DCL reader Luigi T. saidIt would be very useful for my needs, but at the moment the source code seems to not be available.
LZO.Net Rate A .NET wrapper around the native LZO libraries.
LZO download site Rate The primary site for downloading LZO files. This includes mini-LZO, a shrunk down version of the LZO library, Perl-LZO, and Python-LZO.
Non-Commercial Programs

LZOP Binary Download Site Rate
The author created this site to make LZOP readily available. The page has links to download binaries, plus links to other LZO and LZOP sites.
LZOP Rate
The home page for lzop – a file compressor that is built on the LZO compression library. lzop is free under the GPL.
Version 1.01 of LZOP shipped in April of 2003.
Papers/Documentation

The LZO documentation Rate
Concise documentation on LZO.
LZO FAQ Rate The first question in the FAQ: I hate reading docs – just tell me how to add compression to my program
People

Markus Franz Xaver Johannes Oberhume Rate Personal home page for Markus Franz Xaver Johannes Oberhumer, the author of LZO
Source Code

LZO Streaming Code Rate Tom St Denis posted an article on comp.compression announcing free source code for streaming to and from files using the LZO engine. This link takes you to stream.c, modify it slightly to get stream.h, the corresponding header file.
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LZ77/LZSS and derivatives

This topic encompasses the LZ77 algorithm and its descendant, LZSS. This is one of two seminal LZ compression algorithms developed in the late 70s. LZSS forms the core of the popular deflate algorithm when combined with a Huffman encoder on the back end.
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Commercial Libraries

PKWare Data Compression Library Format Rate
In this comp.compression posting, Ben Rudia-Gould opens up the compression format used by the PKWare Data Compression Library. This is the only place I have ever seen this information disclosed; PKWare has certainly not done so.
LZSLib – a windows compression .DLL for windows programmers. Rate
LZSSLib is a compression library (DLL) for Windows programmers. You have access to compression/decompression functions permitting file-to-file operations. LZSSLib uses the LZSS algorithm with various modifications each providing different enhancements. Very simple to use: LZSSPackFile(‘PROG.EXE’, ‘PROG.LZS’) Works with any language that supports DLL calling, such as Turbo Pascal, C/C++, Actor, Visual Basic, Realizer, even ObjectVision.
TCompress Component Set Rate
File and database compression components for Delphi. Compress to/from file, memory, and blob. Uses RLE, LZH, and LZW. Shareware.
Version 7.0 was released in September of 2002.
UPL Compression : the complete professional toolkit Rate
The UPL Compression Library is a high-performance professional compression library. It offers the ability to compress and decompress data, buffers, strings or single files and features the latest innovations in data compression. The library offers eight extremely powerful compression algorithms. Dynamic Huffman, Arithmetic, BWT, Ppm and several Lempel Ziv flavors.
DataCompression.info user John G. had this to say: I was looking for adding a better compression to my Visual Basic project and it worked like a charm. The compression ratio is really good, better than Zip!
Free DCL Decompressor Rate Mark Adler built a decompressor that is able to read streams built with PKWare’s Data Compression Library. Since PKWare hasn’t released source for DCL, this is a very good thing, and free to boot.
DCompress v1.00 library Rate For Delphi and other Windows compilers. Compression/ Decompression routines .DLL library. Mostly assembler, Fast decompression!
More PKWare DCL Decompression Code Rate C++ code posted to comp.compression that describes extraction from PKWare’s Data Compression Library.
Update: The author posted this correction to comp.compression: There’s a bug in the code posted 2001-10-07 19:36:38 PST. To fix: In the
void tcDecoder::Decode(char *apBuffer, unsigned int *apSize, unsigned int anBufferSize)
function after both
if (lnIndex == mnCurrentPos) lnIndex = lnStartIndex;
add
if (lnIndex == mnDictionarySize) lnIndex = 0;
Courses/Seminars

Redundanz – Lempel-Ziv-Kodierung Rate
A lecture in German on LZ coding.
German

LZ77 Daten – Dekompression auf dem 68HC11 Micro Controller Rate Christian Scheurer wrote up his LZ77 project that was targeted to the 68HC11 processor. It’s written in German, perhaps you could use Babel-fish to translate. Source code included.
Newsgroup Posts

More PKWare DCL Decompression Code Rate C++ code posted to comp.compression that describes extraction from PKWare’s Data Compression Library.
Update: The author posted this correction to comp.compression: There’s a bug in the code posted 2001-10-07 19:36:38 PST. To fix: In the
void tcDecoder::Decode(char *apBuffer, unsigned int *apSize, unsigned int anBufferSize)
function after both
if (lnIndex == mnCurrentPos) lnIndex = lnStartIndex;
add
if (lnIndex == mnDictionarySize) lnIndex = 0;
Non-Commercial Libraries

lz.adb Ada source for compression based on the LZH package.
LZMA SDK From 7-Zip Rate
Igor Pavlov has released his LZMA code in a separate SDK, and is claiming excellent performance characteristics that make this a potential hit in the embedded world.
Collake Software – JCALG1 Rate
Home of JCALG1, an LZSS derived lossless compression algorithm with full x86 32bit assembly source. Data Compressioni Library user comment: I found LZSS C source and an EXE. The EXE was useful for testing. I expect to use this in an embedded app after further research..
Tlzrw1 : Delphia compression component with LZH and LZRW1/KH Rate The LZH and LZRW1/KH routines are from the SWAG Pascal code archive.
The African Chief Rate The African Chief has a variety of compression programs listed here, including units for Delphi and Turbo Pascal. Techniques supported include LZSS and Zip. Most appear to include source.
Free DCL Decompressor Rate Mark Adler built a decompressor that is able to read streams built with PKWare’s Data Compression Library. Since PKWare hasn’t released source for DCL, this is a very good thing, and free to boot.
JCALG1 Rate JCALG1 is a small, open-source, LZSS derived compression library.
Features Coded in 100% 32bit x86 assembly language for maximum performance and minimum size.
Good compression ratio, typically much better than ZIP’s deflate.
Extremely small and fast decompressor.
Adjustable window size to allow for faster compression at the cost of compression ratio.
Decompression requires no memory, other than the destination buffer.
Easy integration with any application.
Free!
BriefLZ Rate An Open Source library that implements an LZSS algorithm, designed for speed. ANSI C, with 16- and 32-bit x86 assembler versions available as well.
The Standard Function Library: Compression Functions Rate The guys at iMatix had the idea that they could write a super-library of C functions that woud be so useful it would rule the world. As far as I can tell, it didn’t catch on. However, there are a few compression functions here that some folks might find interesting.
TLZHCompressor a compression component for Delphi Rate This unit implements a component which allows the user to compress data using a combination of LZSS compression and adaptive Huffman coding (Similar to that use by LHARC 1.x), or conversely to decompress data that was previously compressed by this unit.
Non-Commercial Programs

rzip Rate rzip is a compression program, similar in functionality to gzip or bzip2, but able to take advantage long distance redundencies in files, which can sometimes allow rzip to produce much better compression ratios than other programs. The original idea behind rzip is described in my PhD thesis (see http://samba.org/~tridge/), but the implementation in this version is considerably improved from the original implementation. The new version is much faster and also produces a better compression ratio.
McKee’s Directed Acyclic Graph Compression Rate Will McKee has released this as freeware – includes complete source to a string substitution compressor. From the description it sounds as though it’s variant on LZSS, but I’ll defer to anyone willing to do a real analysis.
Compreso Rate Compreso implements compressed sockets using an LZH algorithm, as implemented by Rolando Herrero. It does this cooperatively with the Win32 socket library, so you can only run this code under Windows. Freeware.
Papers/Documentation

An Optimizing Hybrid LZ77 RLE Data Compression Program Rate
An Optimizing Hybrid LZ77 RLE Data Compression Program, aka Improving Compression Ratio for Low-Resource Decompression by Pasi Ojala.
Presents a new literal tagging system, a fast exhaustive string match algorithm, an optimal parsing algorithm, and results on Calgary Corpus and Canterbury Corpus.

LZ77 compression Rate
The definition of LZ77 from the Free On-line Dictionary of Computing.
A Universal Algorithm for Sequential Data Compression Rate The 1977 paper describing an algorithm for compression using pointers to previously seen text. This algorithm, later known as LZ77, is still one of the most widely used techniques for lossless data compression in use today.
Update 2004: Document is now packed in RAR format.
Improving the Speed of LZ77 Compression by Hashing and Suffix Sorting Rate by Kunihiko Sadakane, Hiroshi Imai. This paper proposes two new methods of performing fast string matching in LZ77 compression. One method uses a new hashing algorithm, the other uses suffix sorting.
Dictionary Selection using Partial Matching Rate D. T. Hoang, P. M. Long and J. S. Vitter. “Dictionary Selection using Partial Matching,” Information Sciences, 119(1-2), 57-72, 1999. This paper describes an attempt to squeeze improved compression out of existing dictionary-based schemes by using multiple context-based dictionaries for encoding.
People

Ross Williams Rate
Ross Williams did some seminal work in the area of dictionary based encoders in the late 1980s and early 1990s. His LZRW algorithms were not only innovative and interesting, but they managed to place Ross right in the middle of some early software patent issues.
High School Kids Win Prizes for Compression Algorithm Rate A couple of high school kids from Saratoga, CA, were regional winners in the Siemens Westinghouse Science and Technology competition.
Source Code

Fast String Searching With Suffix Trees This article describes a relatively painless way to construct suffix trees. Once you have a suffix tree constructed, it is extremely easy to search for the longest match of a given string. This makes the suffix tree a nice data structure to use in macro replacement forms of data compression.
Michael Dipperstein’s LZSS Code Page Michael Dipperstein describes his personal quest for understanding and implementation of LZSS coding. Full source included.
Jonathan Bennet’s C++ implementation of LZSS Rate
A C++ implementation of the LZSS / LZ77 algorithm. Also contains a description of the LZSS algorithm and my implementations of it as I learned more about it (hashing, lazy evaluation, etc.) All the code from my first attempt to the current version is included.
An anonymous visitor to Jonathan’s page said it was “Pertinent, very useful, relevant, just what I needed.”
lszz.c, lzhuf.c, and lzari.c Rate
This archive contains source files lzss.c, lzhuf.c, and lzari.c. They have virtually no documentation, but do a good job of compression. These files were quite influential in their day, particularly in Japan.
An Optimizing Hybrid LZ77 RLE Data Compression Program Rate
An Optimizing Hybrid LZ77 RLE Data Compression Program, aka Improving Compression Ratio for Low-Resource Decompression by Pasi Ojala.
Presents a new literal tagging system, a fast exhaustive string match algorithm, an optimal parsing algorithm, and results on Calgary Corpus and Canterbury Corpus.

Lossless Data Compression Toolkit Rate
Version 1.1 of the lossless data compression toolkit by Nico deVries. The C sources in this toolkit include an LZW compressor, AR002 archiver, a PPM like compressor using arithmetic compression, Huffman compressor, splay tree program, and LZRW1. Quite a variety.
Dictionary Coders Rate
This page has links to the source code for a family of compressors written by Charles Bloom. This includes the LZP family, an LZW example, LZRW, and LZCB.
Collake Software – JCALG1 Rate
Home of JCALG1, an LZSS derived lossless compression algorithm with full x86 32bit assembly source. Data Compressioni Library user comment: I found LZSS C source and an EXE. The EXE was useful for testing. I expect to use this in an embedded app after further research..
LZ77 Daten – Dekompression auf dem 68HC11 Micro Controller Rate Christian Scheurer wrote up his LZ77 project that was targeted to the 68HC11 processor. It’s written in German, perhaps you could use Babel-fish to translate. Source code included.
The Standard Function Library: Compression Functions Rate The guys at iMatix had the idea that they could write a super-library of C functions that woud be so useful it would rule the world. As far as I can tell, it didn’t catch on. However, there are a few compression functions here that some folks might find interesting.
McKee’s Directed Acyclic Graph Compression Rate Will McKee has released this as freeware – includes complete source to a string substitution compressor. From the description it sounds as though it’s variant on LZSS, but I’ll defer to anyone willing to do a real analysis.
Standards

ITU Recommendation V.44 Rate This is the data compression standard that implements the LZJH algorithm, and is used in V.90 and V.92 modems. The ITU wants to charge you a few bucks for this standard, but if you believe the post from Pete Fraser (listed elsewhere on DataCompression.info) you can get three free standards per year. Maybe this ought to be one of them.
Tutorials, Reference, Presentations

LZ77 the basics of compression (2st ed.) Arturo Campos explains some of the basics about LZ77 compression and its popular descendant, LZSS. This is one of Arturo’s longer articles, and it includes a hefty does of 80×86 code for illustration purposes.
Lzp research Arturo Campos has been doing quite a bit of research on the LZP algorithm (first described by Charles Bloom.) This paper presents all of his results to date.
Lzp Arturo Campos presents the LZP algorithm, first described by Charles Bloom. LZP is a hybrid of dictionary based coding and statistical modeling. This means it has some of the elements of popular LZSS encoders, but takes advantage of PPM style modeling as well. The combination of the two leads to very good compression ratios.
Flexible parsing Arturo Campos explains how your implentation of an LZ77 compressor might benefit from an improved parsing algorithm. Instead of always using the longest match found at at the current position, Flexible Parsing attempts to find the optimal match which will lead to the best overall compresion.
Fast String Searching With Suffix Trees This article describes a relatively painless way to construct suffix trees. Once you have a suffix tree constructed, it is extremely easy to search for the longest match of a given string. This makes the suffix tree a nice data structure to use in macro replacement forms of data compression.
Michael Dipperstein’s LZSS Code Page Michael Dipperstein describes his personal quest for understanding and implementation of LZSS coding. Full source included.
Lzp order-3 with linked lists Another article about LZP by Arturo Campos. This piece describes a specific implementation technique using linked lists.
PKWare Data Compression Library Format Rate
In this comp.compression posting, Ben Rudia-Gould opens up the compression format used by the PKWare Data Compression Library. This is the only place I have ever seen this information disclosed; PKWare has certainly not done so.
Algoritam LZSS Rate
A discussion of LZSS in Croatian. This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
The LZSS Algorithm Rate
The Data Compression Center gives an explanation of LZSS coding. This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
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LZ78/LZW and derivatives

This topic encompasses the LZ78 algorithm and its descendant, LZW. LZ78 is one of two seminal compression algorithms developed in the late 1970s. LZW is best know as the core compennt of the GIF compression format.
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Commercial Libraries

Java PDF Libraries Rate
A variety of libraries that can be used to read and write PDF format.
TCompress Component Set Rate
File and database compression components for Delphi. Compress to/from file, memory, and blob. Uses RLE, LZH, and LZW. Shareware.
Version 7.0 was released in September of 2002.
GAO Research Modem Software Rate GAO Research sells modem software for quite a few different platforms, including a big batch of DSP parts. Naturally, this includes modules to perform both V.42bis and V.44 data compression.
Companies/Organizations

Unisys LZW Page Rate
Some information on LZW, it looks as though this has info on Licensing, but I’m not sure. All information is in Japanese.
Courses/Seminars

Redundanz – Lempel-Ziv-Kodierung Rate
A lecture in German on LZ coding.
French

Contributions à la compression de données Rate Steven Pigeon’s Ph. D Thesis from the University of Montreal. Proposes a new set of universal codes, which he dubs taboo codes, as well as new optimization algorithms for (Start, Step, Stop) codes. Plus lossy variations on LZW.
Japanese Language Resources

Unisys LZW Page Rate
Some information on LZW, it looks as though this has info on Licensing, but I’m not sure. All information is in Japanese.
Links

Lempel-Ziv Welch – NIST Reference Page Rate The National Insitute of Standards and Techology reference page on LZW compression. Pointers to an explanation, implementation, and more information.
Newsgroup Posts

What is the V.42bis standard? Rate
The comp.compression FAQ tells you a little bit about this modem standard.
LZW Patent Expiration Rate
This thread reveals the actual dates for the LZW patent expiration, including US, European, and Japanese patents.
Non-Commercial Libraries

Java PDF Libraries Rate
A variety of libraries that can be used to read and write PDF format.
Non-Commercial Programs

The Multivalent Browser Rate
This Java browswer knows how to render PDF files, which means it understands the elusive LZW compressed data format used by Adobe.
Xpdf Rate
This is an open source PDF renderer, which includes code that decompresses LZW data embedded in the PDF file. It doesn’t actually do the LZW decompression itself – it converts the data to a format that can be handled by UNIX compress.
Papers/Documentation

LZ78 compression Rate
The definition of LZ78 from the Free On-line Dictionary of Computing.
Lempel-Ziv Welch compression Rate
The definition of LZW from the Free On-line Dictionary of Computing.
LZW – Webopeidia reference page Rate
Short for Lempel-Zif-Welsh, a popular data compression technique developed in 1977 by J. Ziv and A Lempel, and later refined by T. Welsh. It is the compression algorithm used in the GIF graphics file format, which is one of the standard graphic formats used by CompuServe and the World Wide Web.
Contributions à la compression de données Rate Steven Pigeon’s Ph. D Thesis from the University of Montreal. Proposes a new set of universal codes, which he dubs taboo codes, as well as new optimization algorithms for (Start, Step, Stop) codes. Plus lossy variations on LZW.
Dictionary Selection using Partial Matching Rate D. T. Hoang, P. M. Long and J. S. Vitter. “Dictionary Selection using Partial Matching,” Information Sciences, 119(1-2), 57-72, 1999. This paper describes an attempt to squeeze improved compression out of existing dictionary-based schemes by using multiple context-based dictionaries for encoding.
Compression of Individual Sequences via Variable-Rate Coding Rate by Ziv and Lempel. The seminal LZ78 paper which spawned LZW, GIF, and an entire academic industry.
Update 2004: Document is now packed in RAR format.
Patents/Licenses

Unisys LZW Page Rate
Some information on LZW, it looks as though this has info on Licensing, but I’m not sure. All information is in Japanese.
License Information on GIF and Other LZW-based Technologies Rate
A Unisys press release explaining their beliefs regarding licensing required to use GIF technology in your products. As of this posting (8/2003) the US patents appear to have expired, but there are European and Japanese patents will not expire until some time in 2004.
LZW Patent Expiration Rate Drew Scott Daniels was attempting to find out when all the LZW patents all over the world were going to expire. This is not as easy as you might think! Drew was kind enough to forward links to the message boards where the question was posted. To follow the thread, go to the bottom of the page and click on the Next by thread link.
Source Code

LZW Data Compression by Mark Nelson Mark Nelson’s Dr. Dobb’s article on LZW compression from October 1989. Includes source code in C.
Dictionary Coders Rate
This page has links to the source code for a family of compressors written by Charles Bloom. This includes the LZP family, an LZW example, LZRW, and LZCB.
David Scott’s Bijective LZW Compression Methods Rate
David describes his work creating a bijective LZW compressor. (See this and other pages of David for details on what he means by bijective.) The page includes C++ source.
The Multivalent Browser Rate
This Java browswer knows how to render PDF files, which means it understands the elusive LZW compressed data format used by Adobe.
Introduction On Text Compression Using Lempel, Ziv, Welch (LZW) method Rate
Cheok Yan Cheng decided to write up a short tutorial on LZW compression. It is presented here, along with some source code.
Lossless Data Compression Toolkit Rate
Version 1.1 of the lossless data compression toolkit by Nico deVries. The C sources in this toolkit include an LZW compressor, AR002 archiver, a PPM like compressor using arithmetic compression, Huffman compressor, splay tree program, and LZRW1. Quite a variety.
Xpdf Rate
This is an open source PDF renderer, which includes code that decompresses LZW data embedded in the PDF file. It doesn’t actually do the LZW decompression itself – it converts the data to a format that can be handled by UNIX compress.
LZW Compression Rate An article that describes itself as showing how to implement LZW compression in MFC.
LZW compression Rate A page with a brief description of LZW compression by Dominik Szopa. This page includes a Java applet that helps show how LZW looks in action.
Bill Luoma’s Compression Links Rate Bill has some Java LZ78 code here, along with a few other links to compression info.
Standards

Standard ECMA-151 Data Compression for Information Interchange – Adaptive Coding with Embedded Dictionary – DLCZ Algorithm Rate An LZW variant that has been adopted as a standard by the ECMA.
Tutorials, Reference, Presentations

LZW Data Compression by Mark Nelson Mark Nelson’s Dr. Dobb’s article on LZW compression from October 1989. Includes source code in C.
Lzw, gif decoding Arturo Campos describes the specific implementation of LZW compression used in GIF files.
The LZW algorithm Rate
A nice explanation of LZW compression from the fine folks at the Data Compression Center. This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Video and Audio Compression Rate
Class notes on lossless compression algorithms. Quick info on Huffman, Adaptive Huffman, and LZW.
The Lossless Compression (Squeeze) Page Rate
This page is designed made to teach people about Lossless compression algorithms through the use of text graphics and Java Applets! Dominik Szopa has created pages that demonstrate Huffman, Adaptive Huffman, and LZW compression.
DCL reader SF has this to say: While the site itself is rather quick, it’s disorganized…the Java applets really don’t show what’s going on at all. They show only the external effects…This site has definate potential, and I do recommend people see it. However, it’s also got a ways to go yet. .
Lossless Compression Algorithms (Entropy Encoding) Rate
An overview of the basics, including Shannon-Fano, Huffman, Arithmetic coding, and a section on LZW for good measure.
David Scott’s Bijective LZW Compression Methods Rate
David describes his work creating a bijective LZW compressor. (See this and other pages of David for details on what he means by bijective.) The page includes C++ source.
Introduction On Text Compression Using Lempel, Ziv, Welch (LZW) method Rate
Cheok Yan Cheng decided to write up a short tutorial on LZW compression. It is presented here, along with some source code.
About LZW Compression Rate A tutorial by Martin Zolnieryk on LZW, along with some pseudo code and links.
LZW Compression Rate An article that describes itself as showing how to implement LZW compression in MFC.
Replacing a Dictionary with a Square Root Rate Tom Cagill creates GIF files without using LZW.
LZW and GIF explained Rate A guy named Steve Blackstock takes a shot at making this all clear to you. Gives some details on the LZW variation used in GIF files.
LZW compression Rate A page with a brief description of LZW compression by Dominik Szopa. This page includes a Java applet that helps show how LZW looks in action.
Algoritam LZW Rate Description of the LZW algorithm in Croatian.
LZW Definition Rate A short (and incorrect) definiton of the acronym LZW from Computer Knowledge.
LZW Examples Rate Notes from an Information Theory course at MIT.
Bill Luoma’s Compression Links Rate Bill has some Java LZ78 code here, along with a few other links to compression info.
Wikipedia Entry: LZW Rate The Wikipedia entry for LZW compression. Good overview with plenty of links.
Lempel-Ziv-Welch (LZW) Compression Rate A good description of LZW, along with some specific information about TIFF’s implemenation of this compression algorithm.
Unknown/Other Language

Algoritam LZW Rate Description of the LZW algorithm in Croatian.
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Markov Modeling

Markov modeling is essentially a method to predict the probability of a given character based on what has come before it. The best know type of Markov modeling is known as PPM, which has its own category. This topic covers all things Markov that are not PPM-related.
[ Deja News ] Search compression newsgroups for references to this topic
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Newsgroup Posts

General Prediction Rate
Some thoughts on modeling from Charles Bloom.
Papers/Documentation

Publications of Gordon V. Cormack Rate A set of links to Cormack’s publications. Papers germane to this page include one on DMC and arithmetic compression. Pointers to many other data compression articles which are unfortunately not linked to this page.
People

Gordon V. Cormack Rate
Gordon is the author of DMC and many publications related to data compression. This is is home page, which has links to much of his work.
Source Code

Markov Coders Rate
A set of Markov compressors by Charles Bloom, including source code. This includes links to a wide variety of his programs, including Context Coders, List LRU, and DefSum, along with a link to an early paper of his.
DMC.C Rate
Software implementing a complete DMC codec, plus code for a couple of different arithmetic encoders, and a linear time Huffman tree builder.
This program implements Dynamic Markov Compression (DMC) as described in “Data Compression using Dynamic Markov Modelling”, by Gordon Cormack and Nigel Horspool in Computer Journal 30:6 (December 1987). The Guazzo arithmetic coder is used here.

Publications of Gordon V. Cormack Rate A set of links to Cormack’s publications. Papers germane to this page include one on DMC and arithmetic compression. Pointers to many other data compression articles which are unfortunately not linked to this page.
Standards

DWC File Format Rate
An explanation of the archaic DWC file format.
Tutorials, Reference, Presentations

Markov Coders Rate
A set of Markov compressors by Charles Bloom, including source code. This includes links to a wide variety of his programs, including Context Coders, List LRU, and DefSum, along with a link to an early paper of his.
Return to The DataCompression.info home page
Copyright © 2000-2002, Mark Nelson, All Rights Reserved.
Copyright © 2005 Visicron Corp. All rights reserved.
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MP3/MPEG Audio

MP3 is the popular name for MPEG Audio Layer 3 encoding. This page covers this specific form of compression that is populary used for music, as well as some forays into Layer 2 and Layer 1 encoding.
[ Deja News ] Search compression newsgroups for references to this topic
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Commercial Libraries

Epigon Media Technologies Rate
It’s a little hard for me to tell what Epigon is selling. They have a nice picture of some kind of board on their front page, but I don’t think they have any hardware for sale. They do appear to have audio codecs for MPEG-1, MPEG-2, and MPEG-4, as well as what appears to be a proprietary speech codec called eSpeech.
Note: Reader Ragu says that despite the problem siwith the web page, he is a big fan of their products. He is a satisfied customer who feels their audio codecs are the best.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
Commercial Programs

Media Digitalizer Rate
This appears to be a tool that is designed to aid you in the process of digitizing your LPs and cassettes to your PC. It will export to MP3 format, which explains its presence here.
Xing AudioCatalyst Rate
AudioCatalyst is a commercial program that creates and playsback MP3 files. The recorder can rip tracks from music CDs and convert them to MP3 files in many different formats. A trial edition of the product is available at this web site.
RealNetworks MPEG Encoder (was Xing) Rate
Xing’s encoder creates both audio and video MPEG streams.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
Advanced MP3 Converter Rate This conversion tool will convert between several audio formats, including WAV, OGG, and MP3. Supports ID3V1 and V2, plus other goodies.
Helix DNA Client Rate Real is making their client software available in an Open Source program. Download this software and you can develop your own MP3 player! Free of royalties if you are distributing it for free – commercial products pay a royalty.
WMA MP3 Recorder Rate WMA MP3 Recorder turns your computer into complete audio recording studio. You can record sound from any internal or external source into WMA/MP3 format sound file directly without use additional disk space.
Version 5.60 is shipping as of April, 2003
ADI MPEG Audio Player Rate A plugin for the Netscape browser that lets you listen to MPEG audio streams.
Power WMA Recorder Rate Power WMA Recorder is a program that can create WMA files from any available sound source directly without using any additional disk space. In addition to supporting Microsoft’s WMA format (including the variable bit rate option), Power WMA Recorder can encode directly to MP3 format.
Version 1.34 is shipping in March, 2003.
Visual Text To Speech MP3 Rate This product takes your text, converts it to speech, then stores the result in one of several compressed formats, including MP3, Ogg Vorbis, and G.721.
MP3 Splitter & Joiner Rate An MP3 editor, lets you split and join MP3 files, as well as creating or modifying ID3 tags.
Version 2.40 shipped in April, 2003.
WMA To MP3 Converte Rate WMA To MP3 Converter was written for converting WMA to or from MP3/WAV files. So, with WMA to MP3 Converter, you may convert WMA to MP3, convert WMA to WAV, convert WAV to WMA, convert MP3 to WMA.
FairStars Recorder Rate This Win32 program is designed to work directly with your sound card, allowing you to record audio from virtually any source and any program. It makes it into DataCompression.info because it will encode directly to MP3 format.
Version 1.05 is shipping as of March, 2003.
Waver Multiprocessor WAV and MP3 converter Rate Waver is a program that can convert back and forth between MP3 and WAV formats, using the Blade and LAME MP3 codecs. This product’s claim to fame is its ability to soak up all the cycles on more than one CPU simultaneously. So if you’re lucky enough to have a multi-CPU MOBO, you can go to town with this commercial product. You get a 30-day free trial to decide if it’s worth the price.
RIP Vinyl by Wieser Software Ltd Rate Ripping CDs to MP3 format is pretty easy – the CD format lets the ripping program know when one track ends and another beings. Not true for old-schoo vinyl records, and that’s where RIP Vinyl wants to make a difference. It attempts to partition your input into tracks by looking for the gap between songs. Naturally, it has many other options, and will record directly to MP3 format. The program gives you control over the level sampling begins at, and the minimum amount of time that must elapse between tracks, and can record from any audio source on your PC.
No version information seems to be available on the web site.
EXEmp3 Rate This program has a novel approach to the distribution of MP3 files. Instead of just shipping MP3 files around, the folks at EXEmp3 propose packaging the MP3 file with a mini-player executable, as well as a copy of the song’s lyrics. The player only takes up 48K under Windows, and you can unpack the original MP3 file if you like.
Version 1.3 is shipping as of March, 2003.
i-Sound WMA/MP3 Recorder Professional Rate This app from AbyssMedia is advertised as being able to turn your computer into complete audio recording studio. That means you have the ability to record from external inputs directly to MP3, OGG, WMA, or WAV format. Includes niceties such as MP3 and OGG tag editors, Voice Activated recording, skin support, and more.
Version 6.05 is shipping in November, 2003.
Companies/Organizations

Xing Technology Corporation Rate
Xing makes consumer products that support various forms of digital audio. Xing Audio Catalyst is a popular program that supports both creation and playback of MP3 audio.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
Coding Technologies Rate These guys are responsible for some of the work that took the MP3 standard to its next revision: MP3Pro. They say their current focus is the development and marketing of SBR-enhanced codecs.
MP3 Upgrade in the Works? Rate ZDNet reports that MP3 patent holders, Fraunofer Institute and Thomson Multimedia are shopping around a new version of the aging audio standard. Formats such as Microsoft’s Windows Media format have been eating into the MP3 dominance on the net.
Files

MPEG Audio Resources and Software Rate
Links to lots of info regarding the audio compression portions of the MPEG standards. This includes an overview, the MPEG Audio FAQ, pointers to resources, some free software, and test bitstreams.
French

BonkEnc Rate BonkEnc is an audio CD ripper and an encoder for various audio formats. It can produce Ogg Vorbis, MP3 and BONK files. More formats are available through plug-ins.
DropMP3 Rate The author of this program, Philippe Laval, says You are looking for an application to encode your sound files in MP3, DropMP3 is done for you.. The program runs on MacOS, uses the LAME encoder, and is released under the GPL. Note that the web page is more or less duplicated in English and French.
Version 1.0.6 is shipping as of March, 2003.
German

BonkEnc Rate BonkEnc is an audio CD ripper and an encoder for various audio formats. It can produce Ogg Vorbis, MP3 and BONK files. More formats are available through plug-ins.
Hardware

WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
MP3elf – Network MP3 Player Rate The MP3elf is a low-cost Ethernet connected MP3 player that receives a MP3 stream from a local area network server and delivers it to amplified speakers or a Hi-Fi system. You can have a single source of MP3 files in your home or office, and browse through playlists from any MP3elf. The Universal IR receiver allows the MP3elf to respond to one of your existing Remote Controls (or use the on-board pushbuttons) and the LCD interface can display your very own choice of information. The elfServer software design allows compatibility with a range of different front-end options. As it is Java based, it can run on Windows, Macintosh, or Linux machines.
Hardware Support for MP3Pro Rate EE Times reports that both TI and SMT are making chips that support the new MP3Pro format, clearing the way for its inclusion in portable audio devices.
Stream Machines Selling MPEG-2 Chip Rate Stream Machines is selling a dedicate chip that will decode MPEG-1, -2, and -3, along with MP3 and other standards. The chip will be roughly $35 in quantity.
OpenJaz Rate Driver and software for the jazPiper(tm) MP3 player.
Links

MPEG Audio Programmer’s corner Rate
MP3′ Tech calls this “the biggest MPEG audio source codes area avaible on the Internet.” Find source for MPEG-1/2/2.5 Layer 1/2/3, MPEG-2 AAC and MPEG-4, as well as UI code.
Reader Robert S. said It seems very hard to find a description of the Layer 3 bitstream format. Fimally found it here.
askMP3 – The MP3 Portal Rate
MP3.ORG has clustered a bunch of MP3 resources in one location. This is a page of links, links, and more links. If you can’t find a link to what you need here, it probably isn’t an MP3 question.
MP3Tech.org Rate
This site is dedicated to the MP3 standard. You will find here information about the MP3 standard and upcoming audio compression techniques, tests, MPEG source code.
MPEG Audio Resources and Software Rate
Links to lots of info regarding the audio compression portions of the MPEG standards. This includes an overview, the MPEG Audio FAQ, pointers to resources, some free software, and test bitstreams.
ASF vs. MP3 vs. RA-G2 vs. VQF Rate
A comparison of various lossy audio compression schemes. Panos Stokas provides his take on the whole situation, and includes tons of links to files, articles, and more food for thought. Most readers seem to like this web page, but one reader had this negative comment: This website is patently and fatally flawed to the nth degree. Nothing but misconception and conjecture with no real basis in scientific analysis. Very misleading to the uneducated in audio compression.. Another reader says Just reading “However, we have not found a single implementation that did not produce serious amounts of distortion in our testing sample. Nobody seems interested any longer.” about AAC of all things, makes it apparent that this guy has no idea what he’s talking about or what he’s doing.
Jocsoft – MP3 For Developers Rate Jocsoft makes some software products used for searching the web, and one of those is designed to search for MP3 files. As a result, they decided to include a nice page of MP3 links for developers on their web page. It’s a little dated, with a high ratio of dead links, but still worth a look if you’re an MP3 afficionado.
Newsgroup Posts

Doom9’s MPEG Forum Rate This site is mostly oriented towards capturing and storing DVD – good advice on how to use various tools, codecs, hardware, etc. Very active site.
Non-Commercial Libraries

ID3/mp3info Rate
ID3 (or mp3info as it is called on Sourceforge) is a collection of classes useful for reading ID3-tags and ID3v2-tags as well as technical information on the file like bitrates and playing times. It also includes an API to write ID3 (V1 and V2) tags to an mp3 file.
getID3() Rate
This PHP script reads ID3 tags from MP3 files, as well as tons of other tag types from various other audio and other media files.
PlusV Rate PlusV is a brand new audio compression enhancement technology that allows audio files to be compressed in as little as 64 or even 48 kbits/s. PlusV is not a compression scheme of its own, it is an extension that can be applied to existing audio formats. When combined with the MP3 technology, MP3+V files are fully compatible with existing MP3 files and decoders. To get full audio quality out of PlusV files, you just need a PlusV capable decoder, like a PlusV capable WinAmp plugin.
Yet another java id3 lib Rate A Java library that lets you read and write the ID3 tags embedded in MP3 files. Yep, it’s free.
Winamp OpenSource LCD Plugin for various LCD & VFD modules Rate With this plugin your copy of Winamp will display track information on an LCD display attached to your PC. Just the thing if you’re looking to set up a jukebox of some kind, maybe in your car. Windows, free.
MP3Sharp: JavaLayer C# Port Rate A straight-up port of the JavaZoom MP3 library to C#.
CWinamp – more than just a Winamp2 API wrapper Rate A wrapper class that allows you control the Winamp MP3 player from your Visual C++ app.
Non-Commercial Programs

WinAmp Rate
WinAmp is a very popular freeware MP3 player for Windows PCs.
WinAmp is shipping version 5.0.3 as of March, 2004.
LAME Ain’t an Mp3 Encoder Rate
Despite the protestations, you can use LAME to create MP3 streams. It does it with the magic of the ISO demo code. LAME isn’t lame, lots of people seem to like it.
MP3 to Ogg Rate
This is a suite of programs which will help you to convert your existing mp3 files into ogg. The suite includes a text and a graphical frontend. Requires mpg321, mp3info, oggenc, vorbiscomment (zenity for gui).
MPEG Audio Resources and Software Rate
Links to lots of info regarding the audio compression portions of the MPEG standards. This includes an overview, the MPEG Audio FAQ, pointers to resources, some free software, and test bitstreams.
Java MP3 Player Rate
Wouldn’t it be great if there was a free MP3 player written in a portable language like Java? These guys certainly think so.
Version 0.4 was shipping in January, 2004.
DCL user comment: Cool.
Zinf Audio Player Rate
The Zinf audio player is a simple, but powerful audio player for Linux and Win32. It supports MP3, Ogg/Vorbis, WAV and Audio CD playback, SHOUTcast/Icecast HTTP streaming, RTP streaming, a powerful music browser, theme support and a download manager. Zinf is based on the FreeAmp source code. However, AMP® is a trademark of PlayMedia Systems, Inc., and therefore the original name of the project cannot be used any longer. On this website the old project will be referred to as FreeA*p.
Real Time Ac3 Encoder Rate At the time of its addition to the database, this project appears to be in a very early alpha state. Looks as though volunteers are needed!
Mp3Eater Rate The author says:
This page offers very simple but very useful C source code to parse MP3 files. The parser gives detailed info of each frame in the MP3 file. It presents header info, side info and main data corresponding to each frame in the MP3 file. I was not able to find such a tool on the net so I did it myself and now I want to offer it to the world free of cost.
cwenc – MP3 & Ogg Vorbis Encoder for Cakewalk Rate The cwenc utility is primarily a tool for musicians working with Cakewalk music production software, such as Home Studio and Sonar. cwenc enables you to export your original music to a compressed audio file format, such as MP3 or Ogg Vorbis, from within the mentioned Cakewalk products. cwenc is a direct replacement for the time-limited demo-version of Cakewalk’s commercial MP3 encoder program, which is packaged with both Home Studio and Sonar.
MP3elf – Network MP3 Player Rate The MP3elf is a low-cost Ethernet connected MP3 player that receives a MP3 stream from a local area network server and delivers it to amplified speakers or a Hi-Fi system. You can have a single source of MP3 files in your home or office, and browse through playlists from any MP3elf. The Universal IR receiver allows the MP3elf to respond to one of your existing Remote Controls (or use the on-board pushbuttons) and the LCD interface can display your very own choice of information. The elfServer software design allows compatibility with a range of different front-end options. As it is Java based, it can run on Windows, Macintosh, or Linux machines.
Helix DNA Client Rate Real is making their client software available in an Open Source program. Download this software and you can develop your own MP3 player! Free of royalties if you are distributing it for free – commercial products pay a royalty.
mp3stat Rate Mp3stat is Linux a utility program to compare encoders against an MP3 that was VBR encoded. It outputs a linear graphical bitstream analysis of each MP3 being compared and gives you a breakdown of how many frames of each bitrate are found in the MP3. It basically allows you to see how encoders treat areas in the same MP3s differently and lets users discover some of the bitrate effects of different quality levels of the same encoder. Mp3stat also supports Oggs.
Version 2.5.10 of mp3stat is shipping as July 2004.
Information on lossy audiocoding and the MPEGplus-project Rate Mpegplus is an open source lossy encoder that the author apparently has created in response to dissatisfaction with existing MP3 encoders. MP+ has plugins for WinAmp and other players.
mp3record Rate mp3record is a command-line utility for recording any audio (system mixer, input, mic, etc.) directly to an mp3 file on a linux system. It can run for a set interval and shut itself off. Ideal uses for this script would be recording streams, meetings, etc.
Release 1.3 is shipping in March, 2003.
mpeg Encoder – for 95/NT Rate A freeware MP3 Encoder. Not sure of its status, the author seems to be having some licensing problems.
MP3 Streaming DownSampler Rate Damascus Porteng wrote this downsampler that will take an input MP3 stream and resample it at a lower bit rate. Looks like open source that will run on *NIX systems.
MP3Gain Rate This product analyzes and adjusts MP3 files so that they all have the same volume. It appears to be free.
As of Septembery, 2003, Version 1.4.3 is shipping.
CoolPlayer Rate CoolPlayer is a nice, fast MP3 player targeted to Windows. This Open Source project is a nice piece of work, and the team has created a player that has the features to compete with good commercial players.
Build 214 of CoolPlayer shipped in June, 2003.
mp3stego Rate A project that aims to hide information in MP3 files.
MP3 Streaming DownSampler for PHP Rate The MP3 Streaming DownSampler for PHP is written with cable modem/DSL users with low upstream caps in mind. Using LAME, it dynamically downsamples a requested MP3 to a bitrate which can be streamed. It doesn’t use temporary files, so you don’t have to take the time to do any batching, and you just give it a directory with symlinks to your music in a place the Web server can reach. The interface is simplistic and fast, meant for immediate plug and play access.
Freeware Advanced Audio Coder (FAAC) Rate An open source project aiming to create a free codec that supports the MPEG4 LOW and MAIN profiles. Currently available as a command line encoder and Win32 DLL.
Version 1.24 shipped in April of 2004.
Roger Walker’s DOS Port of mpg123 Rate This mp3 player uses the DJGPP C compiler to port the MPG123 player to MS-DOS. Binaries and source available. Version 3.0 appears to have been worked on in 2002, but no history file seems to be available.
VBRFix Rate Will Pye has a program that cleans up some of the problems associated with VBR encoding in MP3 files.
DJWrap Rate From the SourceForge development page for DJWrap: The DJWrap format is an effort to create an open format for combining several MPEG audio streams into one, without losing information about the original files and without disturbing the stream with erroneous or misplaced data.
Version 0.9.2 is shipping as of March, 2003.
BonkEnc Rate BonkEnc is an audio CD ripper and an encoder for various audio formats. It can produce Ogg Vorbis, MP3 and BONK files. More formats are available through plug-ins.
DropMP3 Rate The author of this program, Philippe Laval, says You are looking for an application to encode your sound files in MP3, DropMP3 is done for you.. The program runs on MacOS, uses the LAME encoder, and is released under the GPL. Note that the web page is more or less duplicated in English and French.
Version 1.0.6 is shipping as of March, 2003.
Controlling Winamp2/3/Sonique Programmatically Rate A description of how to control WinAmp from an external program. As a bonus, the techniques work for Sonique 1.x as well. Daniel Bright seems to have come up with this totally via reverse engineering.
http://movix.sourceforge.net/ Rate Directly from the MoviX web site:
The MoviX project is a series of three different tiny Linux CD distributions containing all the software to boot from a CD and play multimedia files through MPlayer, the best multimedia player in the Unix world:
eMoviX: a micro Linux distro meant to be embedded in a CD together with all video/audio files you want, so that the CD will be able to boot and automagically play all files;
MoviX: a mini CD Linux distro able to boot directly from CD and load in RAM a console interface to MPlayer. From the interface you can easily play DVDs, VCDs, audio/video files Audio CD, internet radios, TV, you name it!
MoviX2:same as MoviX, but it makes use of X and makes use of the nice MPlayer GUI.
Supported formats are all formats supported by MPlayer, most noticeably DivX but more in general any AVI, MPG, QuickTime, MP3, OGG/VORBIS and a few others.
eMoviX is at release 0.8.0rc1, MoviX is at 0.8.0pre2, and MoviX2 is at pre0.3.0pre2 as of April, 2003.
LameBrain Rate A freeware MP3 encoder for Mac OS X. Uses the LAME encoder to do all the work, provides a nice GUI front end for all that.
Shipping version 0.5.2, still in beta, as of April 2003.
Papers/Documentation

Technical audio papers Rate
A nice set of papers on audio coding. Includes goodies such as the ISO standards on MPEG-2 part 3 audio coding.
MPEG Audio Layer I/II/III frame header Rate
Docs showing the format for the frame header. You can learn here why MP1 and MP2 files can easily be chopped up and edited, while MP3 is not so easy.
Reader Sebastian L. had this to say: It was the first description that I found and was useful. It’s not the complete standard but it’s a good starting point.
MPEG Audio Resources and Software Rate
Links to lots of info regarding the audio compression portions of the MPEG standards. This includes an overview, the MPEG Audio FAQ, pointers to resources, some free software, and test bitstreams.
Patents/Licenses

MP3 Patent Rate This is reportedly the Fraunhofer patent covering the MP3 compression algorithm.
Results

mp3 Decoder Tests Rate
The author of this page clearly has a bone to pick with some of the MP3 decoders out there. From the site: This site contains test results on a number of mp3 decoders. Such a test wouldn’t be necessary if all decoders worked properly, but unfortunately they don’t. In fact the outputs of many popular decoders were found to be incorrect. .
ASF vs. MP3 vs. RA-G2 vs. VQF Rate
A comparison of various lossy audio compression schemes. Panos Stokas provides his take on the whole situation, and includes tons of links to files, articles, and more food for thought. Most readers seem to like this web page, but one reader had this negative comment: This website is patently and fatally flawed to the nth degree. Nothing but misconception and conjecture with no real basis in scientific analysis. Very misleading to the uneducated in audio compression.. Another reader says Just reading “However, we have not found a single implementation that did not produce serious amounts of distortion in our testing sample. Nobody seems interested any longer.” about AAC of all things, makes it apparent that this guy has no idea what he’s talking about or what he’s doing.
Roberto’s public listening tests page Rate Roberto Amorim is a familiar and friendly presence on the Hydrogen Audio board. This link points to the many audio compression listening tests he has conducted. These include evaluations of AAC and MP3 encoders at a rew different rates.
Source Code

MPEG Audio Programmer’s corner Rate
MP3′ Tech calls this “the biggest MPEG audio source codes area avaible on the Internet.” Find source for MPEG-1/2/2.5 Layer 1/2/3, MPEG-2 AAC and MPEG-4, as well as UI code.
Reader Robert S. said It seems very hard to find a description of the Layer 3 bitstream format. Fimally found it here.
David Weekly’s MP3 Stream Code Snippet Rate
David posted this C code with the following comment: I have no idea if this is useful to folks, but since I had to beat my head against the silly Microsoft APIs for quite some time to get a useable result, I thought it might be helpful to post this little snippet showing you how to find an ACM decoder for MP3s, intiialize it, and use it to decode streaming MP3 buffers.
Reader Simon commented: Need to do some type casting when compiling with Visual C++ 6.0 as well as linking with msacm32.lib..
Java MP3 Player Rate
Wouldn’t it be great if there was a free MP3 player written in a portable language like Java? These guys certainly think so.
Version 0.4 was shipping in January, 2004.
DCL user comment: Cool.
Helix DNA Client Rate Real is making their client software available in an Open Source program. Download this software and you can develop your own MP3 player! Free of royalties if you are distributing it for free – commercial products pay a royalty.
MP3FileInfo – Extract Header and ID3 Tags of a MP3 File Rate This tutorial provides a useful class that lets you access the ID3 tags hidden in most MP3 files.
mp3stego Rate A project that aims to hide information in MP3 files.
C Sharp MP3 Compressor Rate A C# front end for converting WAV files to MP3 format, using the LAME encoder in DLL format.
Spanish

BonkEnc Rate BonkEnc is an audio CD ripper and an encoder for various audio formats. It can produce Ogg Vorbis, MP3 and BONK files. More formats are available through plug-ins.
Standards

MP3 Upgrade in the Works? Rate ZDNet reports that MP3 patent holders, Fraunofer Institute and Thomson Multimedia are shopping around a new version of the aging audio standard. Formats such as Microsoft’s Windows Media format have been eating into the MP3 dominance on the net.
Tutorials, Reference, Presentations

HowStuffWorks: How MP3 Files Work Rate
An article on MP3 encoding, pitched to the layman.
ASF vs. MP3 vs. RA-G2 vs. VQF Rate
A comparison of various lossy audio compression schemes. Panos Stokas provides his take on the whole situation, and includes tons of links to files, articles, and more food for thought. Most readers seem to like this web page, but one reader had this negative comment: This website is patently and fatally flawed to the nth degree. Nothing but misconception and conjecture with no real basis in scientific analysis. Very misleading to the uneducated in audio compression.. Another reader says Just reading “However, we have not found a single implementation that did not produce serious amounts of distortion in our testing sample. Nobody seems interested any longer.” about AAC of all things, makes it apparent that this guy has no idea what he’s talking about or what he’s doing.
Basics about MPEG Perceptual Audio Coding Rate The folks at Fraunhofer give a brief tutorial of some of the basic concepts behind MP3 encoding.
The maths behind MP3 Rate Dr. Keith Devlin writes an article in the UK Guardian explaining a bit about the technology behing the MP3 format.
Wikipedia entry: MP3 Rate This Wikipedia entry describes the MP3 audio format. A good overview with many helpful links.
MPEG Audio Layer-3 Rate An overview and explanation about MP3 from the folks at Fraunhofer. If you want to get a good overview in a single web page, this might be the spot for you.
MP3FileInfo – Extract Header and ID3 Tags of a MP3 File Rate This tutorial provides a useful class that lets you access the ID3 tags hidden in most MP3 files.
MP3 File Structure Rate This reference page breaks down the structure of an MP3 file quite nicely. Covers all the stuff you’ve wanted to know in detail.
The Official FAQ for alt.binaries.sounds.mp3 Rate Not exactly a compression topic, but close enough to make the cut.
Codec capers – The inaudible mystery of the missing bits Rate An article from CommVerge giving a little bit of an overview about data compression using various audio compressors. Two follow-up articles are linked to from this page.Registration required
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MPEG

MPEG is actually an acronym for the Moving Pictures Experts Group, which is responsible for a body of standards regarding digitized video. The family of standards that are grouped under the MPEG umbrella cover a wide variety of compression techniques for motion pictures. Note that the MPEG standards by necessity include compression techinques for audio. Some of these techniques are categorized separately in the MP3 topic.
[ Deja News ] Search compression newsgroups for references to this topic
Please be sure to visit Friends of DataCompression.info! Badtz Maru will be your guide.
Amazon Honor System
Books

Bilddatenkompression/Image Data Compression Rate
Subtitled Basics, Standards and Wavelet-Based Algorithms for Image and Video Coding. This German-language textbook contains full source code (ANSI-C) of a wavelet-based image coder.
Efficient Algorithms for MPEG Video Compression Rate by D. T. Hoang and J. S. Vitter Efficient Algorithms fo MPEG Video Compression, John Wiley & Sons, New York, NY, 2002. This book has just started shipping, I haven’t seen a copy or heard any feedback yet. Provide some if possible!
If you want to buy this book, please use this link to order. Your purchase from Amazon.com will help support this web site.
Commercial Libraries

RareWares AAC Page Rate
A nice collection of AAC software, including encoders, decoders, and miscellaneous plugins.
Elecard Rate
This company has a roster of compression products, including an MPEG-2 Player, an MPEG-2 DirectShow Filter, and a Wavelet Image Compressor.
DataCompression.info user Kuka had this to say: Excellent mpeg player, and a lot of very useful mpeg tools.
PixelTools – the MPEG Experts Rate
MPEG encoders and decoders, authoring software, and libraries.
UB Video, Inc. Rate
UB Video says: UB Video Inc., based in Vancouver, Canada, is a leading provider of coding and transcoding software solutions for video communications. UB Video provides software products that run on desktop PCs as well as on programmable Digital Signal Processors and Media Processors. UB Video’s products include:
Encoders/Decoders
H.261 (Libraries/Source code)
H.263/H.263+ (Libraries/Source code, Encoder/Decoder DirectShow filters, Video for Windows codecs, Java decoder)
MPEG-4 (Libraries/Source code)
MPEG-2 (Libraries/Source code) Transcoders
H.263 to H.261 and H.261 to H.263 (Libraries)
MPEG-2 to MPEG-4 (Libraries) Free demos of the H.263+ codec (UB-Live) and MPEG-4 codec (UB-Stream) can be downloaded from the web site.
TI releases DSP Developer Support for JPEG2000 Rate
Texas Instruments announced the release of a DSP based Image Developer’s Kit, with support coming for JPEG2000, MPEG-4, and other standards.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
MPEGPas Rate A commercial MPEG video compression library written completely in Pascal (Borland Delphi, source code included). A demo version and the documentation can be downloaded.
MainConcept H.264 codec Rate MainConcept is proud to announce the immediate availability of our H.264 Encoder Preview Version for Microsoft® Windows®! Although not yet optimized for speed, this free demo will enable you to sample the quality of our newest codec. H.264 AVC (Advanced Video Coding), also known as MPEG-4 Part 10, is an exciting new standard which offers many advantages and has the potential to replace existing standards.
MainConcept H.264 SDK Rate This SDK decodes and encodes H.264 AVC (Advanced Video Coding) frames, making it easy to add support for this exciting new format to your applications. The MainConcept H.264 Codec will offer ultra-high quality encoding to and decoding from H.264 material at exceptional speeds in all profiles and levels supported by the standard.
PsyTEL Research Rate PsyTEL Research sells a high-quality MPEG-2 and MPEG-4 AAC audio coding library. Free demo (unlimited) is available for download. AAC library is optimized for speed (support for MMX, Pentium II, Pentium III and Pentium IV) and quality (providing AAC quality), supports VBR (variable bitrate coding), etc..
MPEG-4 encoding on a cell phone? Rate This article describes a proof-of-concept app running on a Nokia 7650 that performs MPEG-4 encoding and decoding, creating a portable video phone. No word on how you can get the code, or how difficult it would be to port this Symbios OS product to other platforms. Still, the company that developed the product, Hantro Products, does supply the codecs that do the trick.
DivX Rate This is the current home for the DivX encoder and decoder. DivX ships in three different versions which offer varying levels of features for varying prices (including free.) Shipping DivX Video 5.1.1 as of November, 2003.
DirectX VA Rate Microsoft is providing a Microsoft® DirectX® application programming interface (API) and a corresponding device driver interface (DDI) for acceleration of video codec processing. This API/DDI provides an interface definition focused on support of MPEG-2 “main profile” video (formally ITU-T H.262 | ISO/IEC 13818-2), but also intended to support other key video codecs (ITU-T Recommendations H.263 and H.261, and MPEG-1 and MPEG-4). The interface is designed to extract the most basic computationally-intensive building-blocks of these various codec designs and support their acceleration in hardware.
DivX for Gamecube SDK Rate If you’re a Gamecube developer, you’ve got to like the idea of incorporating DivX video sequences in your games. The great compression levels you can achieve with the MPEG-4 encoding lets you bring an incredible amount of video to this console.
Commercial Programs

Optibase Rate
Optibase claims to be a leading supplier of MPEG content creation tools. Their Web site lists products such as MPEG ComMotion Pro and the The MPEG ComMotion UDP.
RealNetworks MPEG Encoder (was Xing) Rate
Xing’s encoder creates both audio and video MPEG streams.
Elecard Rate
This company has a roster of compression products, including an MPEG-2 Player, an MPEG-2 DirectShow Filter, and a Wavelet Image Compressor.
DataCompression.info user Kuka had this to say: Excellent mpeg player, and a lot of very useful mpeg tools.
PixelTools – the MPEG Experts Rate
MPEG encoders and decoders, authoring software, and libraries.
Ligos Technology Rate
Ligos claims to have the world’s best MPEG-2 encoders. The products are part of the LSX-MPEG family. Take your pick and purchase directly from the web site.
UB Video, Inc. Rate
UB Video says: UB Video Inc., based in Vancouver, Canada, is a leading provider of coding and transcoding software solutions for video communications. UB Video provides software products that run on desktop PCs as well as on programmable Digital Signal Processors and Media Processors. UB Video’s products include:
Encoders/Decoders
H.261 (Libraries/Source code)
H.263/H.263+ (Libraries/Source code, Encoder/Decoder DirectShow filters, Video for Windows codecs, Java decoder)
MPEG-4 (Libraries/Source code)
MPEG-2 (Libraries/Source code) Transcoders
H.263 to H.261 and H.261 to H.263 (Libraries)
MPEG-2 to MPEG-4 (Libraries) Free demos of the H.263+ codec (UB-Live) and MPEG-4 codec (UB-Stream) can be downloaded from the web site.
WIS Technologies, Inc. Rate
WIS Technologies sells software (both standalone and plugins) to perform various types of compression, including wavelet and DCT based lossly algorithms. In addition, they seem to be moving into the hardware business with the announcement of an ASIC JPEG2000 codec.
Philips MP4Net Rate Philips MP4Net web site is here to tell you abou the WebCine line of products, which includes an MPEG-4 Encoder, Server, and Player. It looks like the player is yours for the asking. Other links here explain MPEG-4, as well as offering you careers with Philips.
InterVU MPEG Player Plug-in Rate A browser plug-in for Netscape that lets you view streaming MPEG.
Hyper MPEG Player Rate A Netscape plug-in that lets you display MPEG files online. Avoid the hassle of requiring a complete download before you can start viewing the file.
Download mtv for Linux & Unix Rate mtv is an MPEG TV Player that runs under Linux and UNIX. Besides watching MPEG files from the Interneti, mtv also lets you play Video DVDs. Freeware and commercial versions are available.
LSI Logic / C-Cube Microsystems. Rate C-Cube makes hardware and software encoder and decoders for MPEG video and audio.
C-Cube was engulfed by LSI Logic in 2001, you can now find all of their products here, probably under Professional Codecs and Consumer Products.
iVAST Rate This company labels itself as “The world leader in end-to-end MPEG-4 Solutions.” Looks like they sell a suite of authoring and encoding tools, and perhaps some server software. Follow the link to “About MPEG-4″ and you’ll get a little bit of text plus some more links.
AVI to MPEG Converter Rate This Win32 program will convert your AVI files to various MPEG file types. There is a free version which limits conversions to MPEG-1. The commercial version supports MPEG-2 and various extensions.
Dr. DivX Rate DivXNetworks offers this product which lets you create DivX streams from video in quite a few other sources. They’ve included an MPEG-2 decoder, so you are able to convert DVD content to the new format and save some serious space.
WinMPG Video Convert Rate This is another Swiss-Army Knife converter, letting you move back and forth between AVI, MPEG-1, MPEG-2, DivX, and SVCD formats.
Version 2.5 is shipping as of April, 2003.
GT Technology Rate This site advertises a bunch of nifty looking codecs, including TELP, JPEG, Speech, MPEG, and wavelet compressors. I can’t quite determine exactly what form the products come in.
Precision Digital Images Rate This company makes digital video streaming hardware and software. Although it looks like maybe they don’t actually make the hardware, they help you design it.
IBM Toolkit for MPEG-4 Rate The IBM Toolkit for MPEG-4 consists of a set of JavaTM classes and APIs with five sample applications: three cross-platform playback applications and two tools for generating MPEG-4 content for use with MPEG-4-compliant devices. These applications are as follows:
AVgen: a simple, easy-to-use GUI tool for creating audio/video-only content for ISMA- or 3GPP-compliant devices
XMTBatch: a tool for creating rich MPEG-4 content beyond simple audio and video
M4Play: an MPEG-4 client playback application
M4Applet for ISMA: a Java player applet for ISMA-compliant content
M4Applet for HTTP: a Java applet for MPEG-4 content played back over HTTP.
imageEnhance Rate This product from Teranex removes DCT blocking artifacts from MPEG streams. It also features a few other neat details such as adding the “film look” to digital video.
Vprove from Vqual Rate Vprove is a PC-based software package that analyzes video streams. It is intended as a way for developers to optimize their compressors, doing such things as analysis of motion estimation and image clarity. The product works with H.261, H.263, and MPEG-4 streams. This is a sophisticated product with many interesting features, if you are a content creator or develop content creation tools, you need to check it out.
VECTAR Rate V.E.C.T.A.R. (Video Enhanced Compression for Transmission and Recording) is a high performance video and stereo audio encoder that delivers multimedia content of unprecedented quality across standard broadband and unsurpassed quality across restricted bandwidth. This PCI encoder encodes full motion analog video and stereo audio, and multiplexes it to the system stream to ensure 100% synchronized delivery. Cyber Operations’ patent pending MPEG-X is the groundbreaking technology that makes V.E.C.T.A.R. unique. MPEG-X incorporates MPEG-1, MPEG-2, and MPEG-4 compatibility, and allows V.E.C.T.A.R. to provide higher quality compressed video than any other available technology.
Companies/Organizations

The MPEG home page Rate
An impressive set of links to papers, schedules, articles, and contacts for MPEG. Clearly the place to go for information relating to the standardization process.
Pentamedia Rate
Among other things, these folks make a MPEG 1/2 A/V encoder board for your PC. As an added bonus, their site comes in English, Spanish, and Korean versions.
Cloud Systems Rate
These folks would like to do video compression for you, helping you with your CD-ROM or DVD products.
IETF AVT Working Group Rate
This is the home page for the IETF group that reviews RTP packetization standards. Links on this page for all the drafts you can imagine for sending v