Article View: sci.crypt
Article #3533Re: Need information on data compression algorithms
From: rab
Date: Wed, 22 Apr 1987 07:49
Date: Wed, 22 Apr 1987 07:49
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2199 bytes
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
terrorist cryptography DES drugs cipher secret decode NSA CIA NRO IRS
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!utgpu!water!watmath!clyde!rutgers!ames!ptsfa!well!rab 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 Date-Received: Fri, 24-Apr-87 00:11:04 EST References: <528@savax.UUCP> <635@ttidca.UUCP> <4542@columbia.UUCP> <1323@ihdev.ATT.COM> <4550@columbia.UUCP> Reply-To: rab@well.UUCP (Bob Bickford) Organization: Whole Earth 'Lectronic Link, Sausalito, CA Lines: 29