NAME

ppmtopgm - convert a portable pixmap into a portable graymap

SYNOPSIS

ppmtopgm [ppmfile]

DESCRIPTION

Reads a portable pixmap as input.  Produces a portable graymap as output.  The quantization formula used is .299 r + .587 g + .114 b. 

Note that there is no pgmtoppm converter because any ppm program can read pgm (and pbm) files automagically. 

QUOTE

Cold-hearted orb that rules the night
Removes the colors from our sight
Red is gray, and yellow white
But we decide which is right
And which is a quantization error.

SEE ALSO

ppm(5), pgm(5)

AUTHOR

Copyright (C) 1989 by Jef Poskanzer. 
 
Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation.  This software is provided "as is" without express or implied warranty.

Amiga Unix  —  Last change: 23 December 1988