Developer's Daily | Unix by Example |
main | java | perl | unix | dev directory | web log |
ppmtopgm - convert a portable pixmap into a portable graymap |
ppmtopgm [ppmfile] |
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. |
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. |
pgmtoppm(1), ppmtorgb3(1), rgb3toppm(1), ppm(5), pgm(5) |
Copyright (C) 1989 by Jef Poskanzer. |