Ppmdist User Manual(0)                   Ppmdist User Manual(0)



Table Of Contents


NAME
       ppmdist  -  simplistic  grayscale assignment for machine
       generated, color images


SYNOPSIS
       ppmdist

       [-intensity|-frequency]

       [ppmfile]


DESCRIPTION
       This program is part of Netpbm(1).

       ppmdist reads a PPM image as input and performs  a  sim-
       plistic  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 pro-
       gram 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 per-
       formed in order of input pixel intensity, or input pixel
       frequency (number of repetitions).

       This  program  is  helpful  only  for images with a very
       small number of colors.



OPTIONS
       -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.




SEE ALSO
       ppmtopgm(1), ppmhist(1), ppm(1)


AUTHOR
       Copyright (C) 1993 by Dan Stromberg.



netpbm documentation      22 July 1992   Ppmdist User Manual(0)
