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From: deadman@garnet.berkeley.edu (Ben Haller)
Newsgroups: comp.sys.mac.programmer
Subject: Re: need data compression info
Message-ID: <1990Aug21.094901.29633@agate.berkeley.edu>
Date: 21 Aug 90 09:49:01 GMT
References: <5729@uwm.edu>
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In article <5729@uwm.edu> bowden@csd4.csd.uwm.edu (John William Bowden) writes:
>A while back I seem to remember some source code come thru comp.sys.mac.bin
>that dealt with compressing and decompressing data in a program(PICTs & snds I
>seem to recall.) I cant remember what the file was called, though it seems to
>me that the person who wrote Solarian wrote these routines also. Could anyone
>who knows where I can find this send me a pointer, alternatively if someone 
>could point me in the direction of a book on data compression techniques This
>could also be very helpful.
>
>		Fore-thanks,
>		John W. Bowden 8^)

Hi.  I'm the guy who wrote the code mentioned above.  It's called LZWRes.
It's in the tech directory at sumex-aim.stanford.edu (I *think* it's that
directory, but if not, I *know* it's there somewhere, I saw it today...),
as well as other places no doubt.
  It does LZW compression/decompression on individual resources.  I've
gotten over 50% compression on some 8-bit color pictures, and 30%-40% is
common.  For programs with big pictures this is very helpful.  It brings
Solarian II down from over 1000K (over 1100K?) to about 730K or something.
It is much less effective on sounds, getting from 10% to 20%, hardly worth
the time.
  The package you'll get from an FTP site contains the LZWRes utility and
documentation.  The source code is available for $25, and if you buy it you
are free to use it in your programs.
  Enjoy.  Hope it helps.

-Ben Haller (deadman@garnet.berkeley.edu)