Archives
Aladdin Expander
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.
http://www.stuffit.com/expander/index.htmlIEEE Information Theory Society Web Portal
The home page for the society. Links to newsletters, conferences, tutorials, abstracts, and other miscellaneous fun things.
http://www.itsoc.org/read more from " IEEE Information Theory Society Web Portal "
Carryless Rangecoder
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.
Shorten Utilities (shnutils)
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.
http://freshmeat.net/projects/shnutils/Advanced Encryption Package 2001
This archiving package works with zip files, creates encrypted archives, wipes files, etc.
http://www.secureaction.com/encryption/Huffman-Ricardo Coding
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.
http://www.rootshell.be/~dan/hrc.htmlLZO Streaming Code
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.
http://tom.iahu.ca:8080/src/stream.c.htmlPandora - Markup metadata inside JPEG 2000 files
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.
http://www.migrator2000.org/pandoraread more from " Pandora - Markup metadata inside JPEG 2000 files "
PKWare Data Compression Library Format
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.
http://groups.google.com/groups?q=author:Ben+author:Rudiak-Gould&hl=en&rnum=1&selm=34259d52.0108131038.21dd88f9%40posting.google.comHardware Support for MP3Pro
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.
http://www.eet.com/story/OEG20010921S0021The Glicbawls page
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
http://web.archive.org/web/20020604145417/http://byron.csse.monash.edu.au/glicbawls/index.htmlOn variants of block-sorting compression using context from both the left and right
A technical note from Mike Burrows regarding a variation on block sorting.
http://citeseer.nj.nec.com/432943.htmlDifferences Between Microsoft and Apple ADPCM Files
Apple has published a tech note describing the differences between these two file formats, which on the face of it ought to be identical.
http://developer.apple.com/technotes/tn/tn1081.htmlread more from " Differences Between Microsoft and Apple ADPCM Files "
On2 Technologies VP3.2 Open Source Project
These folks are hard at work on an open source video codec. VP4 appears to be a commercial effort, VP3 seems to be free.
One DataCompression.info user had this to say: Impressive effort by both ON2 and Xiph. Something has to replace MPEG with its rapidly deteriorating technnology and efficiency. This one has the potential but […]
http://www.vp3.comread more from " On2 Technologies VP3.2 Open Source Project "
libcomprex - Comprex (de)compression library
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.
http://www.gnupdate.org/components/libcomprex/index.xmlread more from " libcomprex - Comprex (de)compression library "
Some Summary
This web page explains a proposed categorizaton of various data compression methods.
http://geocities.com/eri32/summary.htmlSorting the matrix of two-sided contexts
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.
http://geocities.com/eri32/slrm.htmArjFolder
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.
http://www.iceows.com/PICTools JPEG2000
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.
http://jpeg2000.jpg.com/
