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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 con-
       tents of	any file. The image  will  be	different   for	 almost	 every
       file with even slightly different contents. Visprint uses the IFS frac-
       tal 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	check-
       sum, 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 depend-
	      ing 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 back-
	      ground, 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	calcu-
	      lation time will quadruple every time you	double this value. The
	      default 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 back-
       ground:

       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 excellent color enhancements	were  added  by	 Raph  Levien.
	      David  Johnston  made  a port for	Win95 console mode and added a
	      bunch of nice features. Soren Andersen  developed	 the  png  and
	      transparency  code.  Goizeder Ruiz de Gopegui, the current main-
	      tainer, cleaned the code,	created	the documentation and put  ev-
	      erything 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)

NAME | SYNTAX | DESCRIPTION | OPTIONS | EXAMPLES | AUTHORS | COPYRIGHT | SEE ALSO

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