ppmdither - ordered dither for color images


   ppmdither  [-dim  power]  [-red  shades] [-green shades] [-blue shades]


   Reads a portable pixmap as input, and applies dithering to it to reduce
   the  number  of  colors used down to the specified number of shades for
   each primary.  The default number 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.


   -dim power    The size of the dithering matrix.  The  dithering  matrix
                 is  a  square  whose dimension is a power of 2.  power is
                 that power of 2.  The default  is  4,  for  a  16  by  16

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

   -green shades The number of green shades to be used,  including  black;
                 minimum of 2.

   -blue shades  The  number  of  blue shades to be used, including black;
                 minimum of 2.


   pnmdepth(1), ppmquant(1), ppm(5)


   Copyright (C) 1991 by Christos Zoulas.

                             14 July 1991                     ppmdither(1)


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