ppmdither(1)

NAME
       ppmdither - ordered dither for color images

SYNOPSIS
       ppmdither  [-dim  dimension] [-red shades] [-green shades]
       [-blue shades] [ppmfile]

DESCRIPTION
       Reads a portable pixmap as input, and applies dithering to
       it  to reduce the number of colors used down to the speci-
       fied number of shades for each primary.  The default  num-
       ber  of  shades  is red=5, green=9, blue=5, for a total of
       225 colors.  To convert the image to a binary  rgb  format
       suitable  for color printers, use -red 2 -green 2 -blue 2.
       The maximum number of colors that can be used is  256  and
       can be computed as the product of the number of red, green
       and blue shades.

OPTIONS
       -dim dimension
                     The size of the dithering matrix.  Must be a
                     power of 2.

       -red shades   The number of red shades to be used; minimum
                     of 2.

       -green shades The number of green shades to be used; mini-
                     mum of 2.

       -blue shades  The  number of blue shades to be used; mini-
                     mum of 2.

SEE ALSO
       pnmdepth(1) ppmquant(1) ppm(5) 

AUTHOR
       Copyright (C) 1991 by Christos Zoulas.