PPMTOMAP

NAME

      ppmtomap - extract all colors from a portable pixmap

SYNOPSIS

      ppmtomap [-sort] [-square] [ppmfile]

DESCRIPTION

      Reads a portable pixmap as input.  Produces a portable pixmap as
      output, representing a color map of the input file. All N different
      colors found are put in an Nx1 portable pixmap.  This color map file
      can be used as a mapfile for ppmquant or ppmtogif.

OPTIONS

      -sort
           Produces a portable pixmap with the colors in some sorted order.
      -square
           Produces a (more or less) square output file, instead of putting
           all colors on the top row.
      All flags can be abbreviated to their shortest unique prefix.

WARNING

      If you want to use the output file as a mapfile for ppmtogif, you
      first have to do a ppmquant 256, since ppmtomap is not limited to 256
      colors (but to 65536).

DEMONSTRATION

      Let a.ppm be a portable pixmap.
      The following command will produce a pixmap that contains all the colors
      of it:
	ppmmerge ppmtomap -square a.ppm > amap.ppm

RESULT

magnified 20 times

SEE ALSO

      ppmtogif(1), ppmquant(1), ppm(5)

AUTHOR

      Marcel Wijkstra (wijkstra@fwi.uva.nl).
      Copyright (C) 1989 by Jef Poskanzer.