ppmdist(1)                                             ppmdist(1)

       ppmdist - simplistic grayscale assignment for machine gen-
       erated, color images

       ppmdist [-intensity|-frequency] [ppmfile]

       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  lev-
       els  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  per-
       formed  in  order of input pixel intensity, or input pixel
       frequency (number of repetitions).

       -frequency    Sort input colors by the number of  times  a
                     color  appears  in the input, before mapping
                     to evenly distributed graylevels of  output.
                     -intensity   Sort   input  colors  by  their
                     grayscale  intensity,  before   mapping   to
                     evenly  distributed  graylevels  of  output.
                     This is the default.

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

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

       Copyright (C) 1993 by Dan Stromberg.

                           22 July 1992                         1