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  • Bijective BWT (7 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    So many of today’s files are already compressed (using old, outdated algorithms) that newer algorithms don’t even get a chance to touch them.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.

Calgary Challenge Update

Posted by Sachin Garg on 31st October 2005 | Permanent Link

Matt Mahoney posted this at comp.compression

I didn’t see it mentioned here but Alexander Ratushnyak won some prize money on the Calgary challenge, http://mailcom.com/challenge/ with an entry of 596,314 bytes on Oct. 25. It consists of a solid archive of 588,183 bytes, plus the decompressor (as C++ source) packed into a RAR
archive. The source is uncommented to save space but appears to be a variant of a previous entry by Przemyslaw Skibinski, which is itself a variant of PAsQDa with a tiny, built in dictionary. The latest version is an improvement of 7KB, consisting of a 4KB improvement in the
archive size and 3KB in the compressed size of the decompressor.

– Matt Mahoney

4 Responses to “Calgary Challenge Update”

  1. Sachin Garg Says:
    October 31st, 2005 at 11:42 am

    Someone looking for something more challanging can probably try hands on Mark Nelson’s Million Random Digits

    http://groups.google.com/group/comp.compression/browse_thread/thread/6b112e6cc87fd19/814f265760609ee7

    http://groups.google.com/group/comp.compression/browse_thread/thread/7cb284374eb99eb5/1779b046ad540e45

    or the $5000 challange

    http://www.geocities.com/patchnpuki/other/compression.htm#Challenge

    Best wishes :-)

  2. Matt Mahoney Says:
    November 2nd, 2005 at 8:18 pm

    Well I have made a bit of progress here. The million random digits aren’t quite random.

    http://groups.google.com/group/comp.compression/browse_frm/thread/987e4ef26de2d7e8/5f6e78cd626577a6?q=million+random+digits+&rnum=1&hl=en#5f6e78cd626577a6

  3. Sachin Garg Says:
    November 3rd, 2005 at 3:31 pm

    Yaa, I remember that thread. :-)

  4. michael maniscalco Says:
    November 4th, 2005 at 9:41 am

    Those digits aren’t random at all. Every time I look that file … the numbers are the same as the last time I looked at them! (^:

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