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Article #6805Re: The "Next Mac" (bitmap conpression)
From: W. H. Pollock x4575 3S235
Date: Wed, 13 Aug 1986 15:22
Date: Wed, 13 Aug 1986 15:22
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1741 bytes
In article <5963@sun.uucp> chuq@sun.uucp (Chuq Von Rospach; Lord of the OtherRealms) writes:
>> I was reading an post on the local bulletin board that rumored Apple had come
>> up with an algorithm for shrinking paint documents in a 31:1 ratio. Imagine
>> a 31K picture saved as 1K on disk. Wow.
>
>Wow is right. The rumor is almost definitely wrong. Compression technology
>of a random bitstream is lucky to get 50% compaction. The compress program
>used for passing news around averages between 35% and 45%.
Ahh, but bitmaps are not "random bitstreams"! I read an article in Abacus
last month which describes a method to compress bitmaps to 0.18 bits/pixels,
which is an 82% gain. (The authors also claimed 2.2 bits/character for text).
The method involves adoptive modeling and dynamic Markov models.
Wayne H. Pollock,
UUCP: ...{ihnp4,cbatt}!cbnap!whp
DELPHI: WHP
GEnie: W.POLLOCK
"The opinions expressed above are ficticious. Any resemblance
to the opinions of persons living or dead is purely coincidental."
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!mnetor!seismo!lll-crg!caip!princeton!allegra!ulysses!mhuxr!mhuxt!houxm!ihnp4!cbosgd!cbatt!cbdkc1!cbnap!whp From: whp@cbnap.UUCP (W. H. Pollock x4575 3S235) Newsgroups: net.micro.mac Subject: Re: The "Next Mac" (bitmap conpression) Message-ID: <161@cbnap.UUCP> Date: Wed, 13-Aug-86 11:22:05 EDT Article-I.D.: cbnap.161 Posted: Wed Aug 13 11:22:05 1986 Date-Received: Fri, 15-Aug-86 20:04:20 EDT References: <5482@topaz.RUTGERS.EDU> <946@unirot.UUCP> <1109@utastro.UUCP> <5963@sun.uucp> Reply-To: whp@cbnap.UUCP (W. H. Pollock x4575 3S235) Distribution: net Organization: AT&T Bell Laboratories, Columbus Lines: 21