From: dawson@cs.cornell.edu (Dawson Dean)
Newsgroups: comp.archives
Subject: [comp.sys.mac.programmer] Best text compression
Followup-To: comp.sys.mac.programmer
Date: 6 Sep 1992 08:25:12 GMT
Organization: Cornell Univ. CS Dept, Ithaca NY 14853
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Archive-name: auto/comp.sys.mac.programmer/Best-text-compression


I sent a message to the original poster last night, but it must
have bounced cuz I havent seen it on the net. Then, I see
everyone saying how swell Huffman is and I've got to put in
my own 2 cents. Its been my experience that a good lzw implementation
blows away Huffman and the best public domain lzw I know of is 
built by Ross Williams, and is called lzrw. There are 5 versions
that have different speed/compression tradeoffs, but all are great.

You can ftp these from sirius.ucs.adelaide.edu.au or check archie
for other archives. Plus, check out comp.compression and
comp.compression.research, for the latest scoop from many people
(including Ross Williams) who know lots more about this stuff
than me.

Here is the readMe from the lzrw release....
----------------
DATA COMPRESSION DIRECTORY
==========================
Date   : 04-Apr-1992.
Author : Ross Williams (ross@spam.ua.oz.au)

This file gives an overview of the data compression directory of the
anonymous ftp archive located at the University of Adelaide, South
Australia. The exact location of the directory is:

   Machine   : sirius.itd.adelaide.edu.au    [IP=129.127.40.3]
   Directory : pub/compression

The directory mostly contains public domain data compression
algorithms developed by Ross Williams during early 1991. It also
contains one or two other items of interest.

The files in this directory may be compressed. Files that are
compressed will have names terminating with ".Z" and will have to be
uncompressed before use (using the Unix "uncompress" command). I
wouldn't trust my files to a data compression algorithm :-), but the
system programmer who put the files there for me (I do not have direct
control over this archive) seems to think that it is a good idea.

Ross Williams
21-Aug-1991

0readme         - This descriptive file.
dc_stan_just    - Justification of dc_stan_spec.
dc_stan_spec    - Proposal for data compression interface standard.
dc_stan_stream  - Revised proposed standard.
dcc91_report    - Report on 1991 Data Compression Conference.
fast_copy.68000 - Fast block move routine for 68000 microprocessor.
lzrw1-a.68000   - LZRW1-A algorithm implemented in 68000 assembler.
lzrw1-a.c       - LZRW1-A algorithm implemented in C
lzrw1-a.txt     - Release notes for LZRW1-A algorithm.
lzrw1.68000     - LZRW1 algorithm implemented in 68000 assembler.
lzrw1.c         - LZRW1 algorithm implemented in C.
lzrw1.tex       - DCC91 conference paper describing LZRW1 algorithm.
lzrw2.c         - LZRW2 algorithm implemented in C.
lzrw2.txt       - Release notes for LZRW2 algorithm.
lzrw3-a.c       - LZRW3-A algorithm implemented in C.
lzrw3-a.txt     - Release notes for LZRW3-A algorithm.
lzrw3.c         - LZRW3 algorithm implemented in C.
lzrw3.txt       - Release notes for LZRW3 algorithm.
lzrw4.txt       - Description of LZRW4 algorithm (not yet implemented).
lzrw45_covering - Release notes for LZRW4 and LZRW5 descriptions.
lzrw5.txt       - Description of LZRW5 algorithm (not yet implemented).
lzrw_headers.h  - Header files (.h files) for C code.
puzzlebox_provpatent - Provisional patent for puzzle box.
rw_info         - Information about Ross Williams and his activities.

WARNING: A patent has recently arisen that may cover one or more of
these algorithms. Please refer to the file rw_info for more
information.

--<End of 0readme file for the compression directory>
-- 
******************************************************************
Dawson Dean                       Internet: dawson@cs.cornell.edu
Dept. of Computer Science         Office:   (607) 255-1179
Cornell University