Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.compression > #1113

Re: entropy of a binary file with conditions

Show all headers | View raw

pierre <pierre@invalid.invalid> wrote:

> let's suppose we have a binary file (runs of zeroes and ones) and its 
> length is 1024 bits.

> any of these runs is not bigger than 8 (00000000 or 11111111)

> how can one compute the entropy of such a file ?

Not enough information. If all the runs are of length 8, then
the entropy is one. Statistically in 1024 bits, one would expect
runs a little longer than 8, but not much. Qualitatively,
the entropy is slightly less than a completely random bit stream,
but not much less.

-- glen

Back to comp.compression | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

entropy of a binary file with conditions pierre <pierre@invalid.invalid> - 2012-03-03 10:04 +0100
  Re: entropy of a binary file with conditions glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-03-03 09:41 +0000
    Re: entropy of a binary file with conditions pierre <pierre@invalid.invalid> - 2012-03-03 10:47 +0100
      Re: entropy of a binary file with conditions glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-03-03 10:00 +0000
        Re: entropy of a binary file with conditions pierre <pierre@invalid.invalid> - 2012-03-03 11:34 +0100
          Re: entropy of a binary file with conditions Alex Mizrahi <alex.mizrahi@gmail.com> - 2012-03-04 00:08 +0200
          Re: entropy of a binary file with conditions "George Johnson" <matrix29@charter.net> - 2012-03-03 22:45 -0500
            Re: entropy of a binary file with conditions "George Johnson" <matrix29@charter.net> - 2012-03-04 01:08 -0500
  Re: entropy of a binary file with conditions biject <biject.bwts@gmail.com> - 2012-03-03 12:34 -0800
    Re: entropy of a binary file with conditions glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-03-03 21:11 +0000
    Re: entropy of a binary file with conditions pierre <pierre@invalid.invalid> - 2012-03-04 20:57 +0100
  Re: entropy of a binary file with conditions "George Johnson" <matrix29@charter.net> - 2012-03-03 22:30 -0500
    Re: entropy of a binary file with conditions Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-03-20 18:49 +0200
  Re: entropy of a binary file with conditions James Dow Allen <jdallen2000@yahoo.com> - 2012-03-03 22:07 -0800
    Re: entropy of a binary file with conditions pierre <pierre@invalid.invalid> - 2012-03-04 20:59 +0100
  Re: entropy of a binary file with conditions Willem <willem@toad.stack.nl> - 2012-03-04 15:41 +0000
    Re: entropy of a binary file with conditions Alex Mizrahi <alex.mizrahi@gmail.com> - 2012-03-04 21:39 +0200
    Re: entropy of a binary file with conditions glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-03-04 22:45 +0000
      Re: entropy of a binary file with conditions Alex Mizrahi <alex.mizrahi@gmail.com> - 2012-03-05 10:03 +0200
        Re: entropy of a binary file with conditions glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-03-05 09:52 +0000
          Re: entropy of a binary file with conditions Alex Mizrahi <alex.mizrahi@gmail.com> - 2012-03-05 18:05 +0200
        Re: entropy of a binary file with conditions James Dow Allen <jdallen2000@yahoo.com> - 2012-03-05 06:03 -0800
          Re: entropy of a binary file with conditions James Dow Allen <jdallen2000@yahoo.com> - 2012-03-05 16:16 -0800
            Re: entropy of a binary file with conditions James Dow Allen <jdallen2000@yahoo.com> - 2012-03-05 16:27 -0800

csiph-web