Ppmdither User Manual(0)			      Ppmdither User Manual(0)



NAME
       ppmdither - ordered dither for color images


SYNOPSIS
       ppmdither

       [-dim power]

       [-red shades]

       [-green shades]

       [-blue shades]

       [ppmfile]


DESCRIPTION
       This program is part of Netpbm(1).

       ppmdither  reads	 a  PPM image 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.

       You  can	 do another kind of dither -- Floyd-Steinberg -- with pnmquant
       or pnmremap.


OPTIONS
       -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 matrix.


       -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.



SEE ALSO
       pamdepth(1), pnmquant(1), pnmremap(1), ppm(1)


AUTHOR
       Copyright (C) 1991 by Christos Zoulas.



netpbm documentation		 14 July 1991	      Ppmdither User Manual(0)