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visprint(1)							     visprint(1)

NAME
     visprint- Fractal fingerprint generator.

SYNTAX
     md5sum (sha1sum) foo.bar | visprint [Options] > foo.png

DESCRIPTION
     Visprint makes cool fractal fingerprint png images based on the contents of
     any  file.  The image  will  be  different  for almost every file with even
     slightly different contents.  Visprint  uses  the	IFS  fractal  generation
     process,  pioneered by Michael Barnsley. It is a way to create images which
     are self-similar to infinite depths. In other words, the picture is made up
     of smaller versions of itself.

     Visprint takes a checksum	as  its  input.  This	is   usually  a  32-byte
     number  which  is generated from a file. In order to generate the checksum,
     you will also need a hash function command such as md5sum or sha1sum.

OPTIONS
     -b(0-255)
	    Use the given background brightness. 0 means black, 255 means white.
	    You can try other values, but the  resultant  image  will  be  quite
	    ugly. The default is 0 (black).

     -c     Use the alternate coloring method. Flips RGB to BGR.

     -a     Create the fractal with 4 different color areas.

     -g     Create  a  semi-grayscale image. The output varies heavily depending
	    on the -b switch.

     -i(1-lots)
	    Use the given intensity of color. With a black background, a  higher
	    intensity produces a brighter image. With a white background, higher
	    intensity  produces  a  darker image. In all cases, calculation time
	    doubles every time you double the intensity. The default is 30.

     -l(32-128)
	    Use the given checksum length. Modify this number to match the  hash
	    function  you  are using.  Examples: 32 for md5, 40 for sha1, 64 for
	    sha256, 128 for sha512...  The output of 128  is  foggy  (but  still
	    useful).  Higher  values will result in crappy images, therefore 128
	    is the maximum accepted. The default value is 32.

     -r(1-1000)
	    Use the given value for both the x and y resolutions.  The	calcula-
	    tion  time	will quadruple every time you double this value. The de-
	    fault is 300.

     -t     Create the image with a transparent background.

     -v     Output version information and exit.

     -?, -h, --help
	    Output help information and exit.

EXAMPLES
     To create a nice 500x500 fingerprint of your kernel type:

     md5sum /boot/mykernel | visprint -r500 > mykernel.png

     Let's say that you want a 100x100 sha1 fingerprint of your website's index
     file, with png transparency that looks good on a white background:

     sha1sum index.html | visprint -l -r100 -b255 -t > index.png

AUTHORS
     Current Maintainer:

	    Goizeder Ruiz de Gopegui http://www.tastyrabbit.net/visprint

     Previous Geniuses:

	    Ian Golderg:    http://http.cs.berkeley.edu/~iang/

	    Raph Leviev:    http://www.cs.berkeley.edu/~raph/

	    Hal Finney:     http://www.rain.org/~hal/

	    David Johnston: http://www.cybercities.com/ston/

	    Soren Andersen: http://intrepid.perlmonk.org/

	    The original code was written by Ian Goldberg, based on an	idea  by
	    Hal  Finney,  in a post to the coderpunks mailing list. The most ex-
	    cellent color enhancements were added by Raph Levien. David Johnston
	    made a port for Win95 console mode and added a bunch  of  nice  fea-
	    tures.  Soren  Andersen  developed	the  png  and transparency code.
	    Goizeder Ruiz de Gopegui, the current maintainer, cleaned the  code,
	    created the documentation and put everything together.

COPYRIGHT
     Copyright 2007 Goizeder Ruiz de Gopegui

     This is free software.  You may redistribute copies of it under the terms
     of the GNU General Public License.

     http://www.gnu.org/licenses/gpl.html.

     There is NO WARRANTY, to the extent permitted by law.

SEE ALSO
     md5sum(1) sha1sum(1)

Goizeder Ruiz de Gopegui	       2.0			     visprint(1)

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