Path: gmdzi!unido!mcsun!uunet!shelby!agate!usenet.ins.cwru.edu!charlie!edguer
From: edg...@alpha.ces.cwru.edu (Aydin Edguer)
Newsgroups: alt.comp.compression
Subject: Wanted: more information for compression survey
Message-ID: <1991Feb15.202748.16511@usenet.ins.cwru.edu>
Date: 15 Feb 91 20:27:48 GMT
Sender: n...@usenet.ins.cwru.edu
Organization: Computer Engineering and Science, Case Western Reserve University
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Originator: edg...@charlie.CES.CWRU.Edu
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Okay.  Help extend this document.

Which programs use which compression algorithms?
compress	Lempel-Ziv-Welch (Wood?)
compact		?
crunsh		Huffman
squeeze		Miller-Wegman
encode		arithmetic encoding
pkzip		Lempel-Ziv (?)

Which of the current algorithms are patented?
Ziv-Lempel		4,464,650
Lempel-Ziv-Welch	4,558,302
Huffman			?
Miller-Wegman		4,814,746
arithmetic encoding	?

What are the definitive articles describing the algorithms?
Lempel-Ziv-Welch
  "A Technique for High Performance Data Compression", Terry A. Welch,
  "IEEE Computer," vol. 17, no. 6 (June 1984), pp. 8-19.


All information here was gathered from previous articles by:
lance...@spock.UUCP
b...@world.std.com
bos...@ucbvax.berkeley.edu
vic...@ibm.com
j...@riacs.edu

Path: gmdzi!unido!mcsun!uunet!samsung!think.com!yale!cmcl2!kramden.acf.nyu.edu!
brnstnd
From: brns...@kramden.acf.nyu.edu (Dan Bernstein)
Newsgroups: alt.comp.compression
Subject: Re: Wanted: more information for compression survey
Message-ID: <11923:Feb1823:02:3091@kramden.acf.nyu.edu>
Date: 18 Feb 91 23:02:30 GMT
References: <1991Feb15.202748.16511@usenet.ins.cwru.edu> 
<1991Feb16.022640.5295@ibmpa.awdpa.ibm.com> <223@qt.cs.utexas.edu>
Organization: IR
Lines: 31

These aren't widely available yet, but quite a few gamma testers have
them, and they're public-domain, so even if I die before sending them to
comp.sources.misc they'll get around.

yabbawhap 0.95	Dan Bernstein	whap: AP coding (James Storer)
yabbawhap 0.95	Dan Bernstein	yabba: Y coding (Dan Bernstein) [unpatented!]

I suggest that the list be tagged with package names, versions, and
authors, as well as compression algorithm designers. There are just too
many ``squeeze''s and ``compress''s and ``squish''s etc. in the world;
the name alone doesn't identify a version.

More precise patent information, stolen from the comments around Woods'
hyper-LZW code:

U.S. patent #4,464,650 by Lempel/Ziv/Cohn/Eastman, assignees Sperry
Corporation and AT&T Bell Laboratories. Invented 1976, published IEEE
Trans. Info Theory, 1978, filed Aug. 10, 1981, awarded Aug. 7, 1984.
[LZ78.]

U.S. patent #4,558,302 by Welch, assignee Sperry Corp., filed June 20,
1983, published 1984, awarded Dec. 10, 1985. [LZW.]

U.S. patent #4,814,746 by Miller/Wegman, assignee IBM, filed June 1,
1983, published 1984, awarded March 21, 1989. [LZW and MW. The earlier
filing date wins.]

U.S. patent #4,876,541 by Storer, assignee Data Compression Corporation,
filed Oct. 25, 1987, awarded Oct. 24, 1989. [AP.]

---Dan