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  • Bijective BWT (6 Comments)

    David Scott has written a bijective BWT transform, which brings all the advantages of bijectiveness to BWT based compressors. Among other things, making BWT more suitable for compression-before-encryption and also give (slightly) better compression.

  • Asymmetric Binary System (113 Comments)

    Jarek Duda’s “Asymmetric Binary System” promises to be an alternate to arithmetic coding, having all the advantages, but being much simpler. Matt has coded a PAQ based compressor using ABS for back-end encoding. Update: Andrew Polar has written an alternate implementation of ABS.

  • Precomp: More Compression for your Compressed Files (3 Comments)

    So many of today’s files are already compressed (using old, outdated algorithms) that newer algorithms don’t even get a chance to touch them. Christian Schneider’s Precomp comes to rescue by undoing the harm.

  • On2 Technologies is Hiring

    There aren’t too many companies working on cutting edge codecs, and of those few this one is hiring. Best of luck.

  • China’s AVS Specifications Available (2 Comments)

    Its old news that China has developed their own Advanced Video Standard to avoid high licensing fees. English translation of the standard is now available, along with the IPR policy. Finally something technical that you can get your hands on to feed your appetite.

The Calgary Corpus Compression Challenge

Posted by Sachin Garg on 7th December 2005 | Permanent Link

On December 3, 2005, the challenge was accepted by Alexander Ratushnyak who sent an entry of size 593620 (payout of $88.25 pending). It continues the series of PAQAR-based entries and requires less than 255 Mb of RAM.

This time the entry consists of two files - a PPMd archive file and a separate data file. The size of the entry is computed as a sum of: the length of the PPMd file (7540), the length of the data file (586071), 3 bytes for the length of the data file, and 6 bytes for the data file name including the terminator.

3 Responses to “The Calgary Corpus Compression Challenge”

  1. c10n.info Says:
    August 5th, 2006 at 4:26 pm

    [...] Alexander Ratushnyak updates his December 2005 entry (of size 593620) to Calgary corpus compression challenge. The new record is 589862 bytes. [...]

  2. Jarnovich Franc Says:
    September 9th, 2007 at 8:53 am

    My own definition of data-base is: Base of all known binary data is finite set of irreducible patterns.

  3. Sachin Garg Says:
    September 9th, 2007 at 8:59 am

    But as all binary data is not ‘known’ yet, that finite set is not fixed size ;-)

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This entry was posted on Wednesday, December 7th, 2005 at 10:12 am by Sachin Garg. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.