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 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).

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

OPTIONS

       In  addition  to  the options common to all programs based on libnetpbm (most notably -quiet, see  Common
       Options ), ppmdist recognizes the following command line 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.

DOCUMENT SOURCE

       This  manual  page was generated by the Netpbm tool 'makeman' from HTML source.  The master documentation
       is at

              http://netpbm.sourceforge.net/doc/ppmdist.html

netpbm documentation                              22 July 1992                            Ppmdist User Manual(1)