Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uwm.edu!src.honeywell.com!msi.umn.edu!cs.umn.edu!ariel.unm.edu!nmsu!opus!ted From: ted@nmsu.edu (Ted Dunning) Newsgroups: comp.compression Subject: primer on compression methods Message-ID: Date: 26 Mar 91 19:54:52 GMT Sender: news@NMSU.Edu Distribution: comp Organization: Computing Research Lab Lines: 28 since so many seem to have missed it, comp.sources.unix just carried dan bernstein's collection of compression programs. while i haven't looked at the code yet, i have read the description in which dan does a very creditable job of describing the LZ family of compression algorithms. if you want a start in finding out more about data compression in a practical sense, you could do much worse than starting with this package. here is the intro from the posting: Submitted-by: Dan Bernstein Posting-number: Volume 24, Issue 73 Archive-name: yabbawhap/part01 [ The file PATENT gives a nice summary of the issues. --r$ ] yabba applies Y compression to its input; unyabba decompresses the result. whap applies AP compression to its input; unwhap decompresses the result. whap and unwhap run at about the same speed as UNIX compress and uncompress, which use LZW coding; yabba and unyabba are two to three times slower. AP and Y compression are typically 10-20% more effective than LZW compression in the same amount of memory. Y coding, unlike LZW coding and AP coding, is unpatented. It should be possible to use these programs on any reasonable C platform, though they were originally designed on a BSD UNIX system.