ppmtopgm(1)     UNIX System V (23 December 1988)      ppmtopgm(1)



     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 although there is a pgmtoppm program, it is not
          necessary for simple conversions from pgm to ppm, because
          any ppm program can read pgm (and pbm ) files automagically.
          pgmtoppm is for colorizing a pgm file.  Also, see ppmtorgb3
          for a different way of converting color to gray.

     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
          pgmtoppm(1), ppmtorgb3(1), rgb3toppm(1), ppm(5), pgm(5)

     AUTHOR
          Copyright (C) 1989 by Jef Poskanzer.


























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