PPMDIST

NAME

      ppmdist - simplistic grayscale assignment for machine generated, color
      images

SYNOPSIS

      ppmdist [-intensity|-frequency] [ppmfile]

DESCRIPTION

      Reads a portable pixmap as input, performs a simplistic grayscale
      assignment intended for use with grayscale or bitmap printers.
      Often conversion from ppm to pgm will yield an image with contrast too
      low for good printer output.  The program maximizes contrast between
      the gray levels output.
      A ppm input of n colors is read, and a pgm of n gray levels is
      written.  The gray levels take on the values 0..n-1, while maxval
      takes on n-1.
      The mapping from color to stepped grayscale can be performed in order
      of input pixel intensity, or input pixel frequency (number of
      repetitions).

OPTIONS

      Helpful only for images with a very small number of colors.  Perhaps
      should have been an option to ppmtopgm(1).

DEMONSTRATION

      Let a.ppm be a portable pixmap.
      The following command will apply the ppmdist filter on it:
	ppmmerge ppmdist a.ppm > adist.ppm

BEFORE

AFTER

SEE ALSO

      ppmtopgm(1), ppmhist(1), ppm(5)

AUTHOR

      Copyright (C) 1993 by Dan Stromberg.