DragonFly On-Line Manual Pages

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
              calculation 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
       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 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
              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)