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From: rab@well.UUCP
Newsgroups: sci.crypt,comp.sys.ibm.pc,comp.sources.wanted
Subject: Re: Need information on data compression algorithms
Message-ID: <2923@well.UUCP>
Date: Wed, 22-Apr-87 02:49:00 EST
Article-I.D.: well.2923
Posted: Wed Apr 22 02:49:00 1987
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Reply-To: rab@well.UUCP (Bob Bickford)
Organization: Whole Earth 'Lectronic Link, Sausalito, CA
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In a previous article Perry Metzger writes:
+  Joe Isuzu writes:
+>Unless you take symbolic representation into account.  Say you
+>numbered the (2^14)-1 words, and used that to replace just the
+>absolute matches (forgetting about endings etc), you would already be
+>elimintating more than you claim, before even implementing redundancy
+>techniques.  If you read a little more on the subject, you would
+>realize there is more than one way to skin a cat.

+Sorry, you still lose. If you do that, you are not compressing an
+ARBITRARY text that much. For instance, if I have 256 books in my
+library, and each one of them contains say a million words (I know
+that is big) you can then compress any book in the library down to 8
+bits, provided that you know that the text you are transmitting is in
+the library. But then, you see, you are not compressing an ARBITRARY
+text, only a text you can find in that limited library. If I pick
+completely random text I can't do that.

  The subject was English text.  Last time I checked, English was not
completely arbitrary.  Illogical, perhaps, but not *completely* arbitrary.
The above described technique would work fairly well on most text,
although I'm not sure whether it would allow you to break the 75% barrier
you previously referred to.  Maybe.


-- 
Robert Bickford         {hplabs, ucbvax, lll-lcc, ptsfa}!well!rab
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