ppmdist(1)

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 repeti-
       tions).

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  out-
                     put.  This is the default.

BUGS

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

SEE ALSO

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

AUTHOR

       Copyright (C) 1993 by Dan Stromberg.

                                 22 July 1992                       ppmdist(1)