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Re: Generating data that can be compressed with a known ratio

From glen herrmannsfeldt <gah@ugcs.caltech.edu>
Newsgroups comp.compression
Subject Re: Generating data that can be compressed with a known ratio
Date 2013-06-22 23:24 +0000
Organization Aioe.org NNTP Server
Message-ID <kq5bmp$flp$1@speranza.aioe.org> (permalink)
References <b2moi3Fd7h3U1@mid.individual.net>

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Ian Collins <ian-news@hotmail.com> wrote:
> I'm looking for an algorithm I can use to generate data that will 
> have a fixed compress ratio when compressed with an ideal 
> compression algorithm (or gzip as a practical compressor).

Choose letter randomly from an appropriate sized alphabet.

If your data has other correlations, then some algorithms
will find them, and others won't, so the compression will be
different.

For random data from an N character alphabet, on a system using
bytes, the compression will be log(N)/log(256). 

-- glen

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Thread

Generating data that can be compressed with a known ratio Ian Collins <ian-news@hotmail.com> - 2013-06-23 10:59 +1200
  Re: Generating data that can be compressed with a known ratio glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-06-22 23:24 +0000
  Re: Generating data that can be compressed with a known ratio SG <sgesemann@gmail.invalid> - 2013-06-23 01:45 +0200
  Re: Generating data that can be compressed with a known ratio hitchmanr@gmail.com - 2013-06-24 11:53 -0700
    Re: Generating data that can be compressed with a known ratio glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-06-24 19:15 +0000
      Re: Generating data that can be compressed with a known ratio hitchmanr@gmail.com - 2013-06-24 13:44 -0700
        Re: Generating data that can be compressed with a known ratio Ian Collins <ian-news@hotmail.com> - 2013-06-25 10:18 +1200
          Re: Generating data that can be compressed with a known ratio hitchmanr@gmail.com - 2013-06-24 16:57 -0700
            Re: Generating data that can be compressed with a known ratio Ian Collins <ian-news@hotmail.com> - 2013-06-25 13:58 +1200
  Re: Generating data that can be compressed with a known ratio Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2013-06-27 10:08 +0300

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