other versions
- stretch 2:10.0-15.3+b2
- testing 2:10.0-15.3+b2
- unstable 2:10.0-15.3+b2
- experimental 2:10.78.05-0.1
| ppmtopgm(1) | General Commands Manual | ppmtopgm(1) |
NAME¶
ppmtopgm - convert a portable pixmap into a portable graymapSYNOPSIS¶
ppmtopgm [ppmfile]DESCRIPTION¶
Reads a portable pixmap as input. Produces a portable graymap as output. The output is a "black and white" rendering of the original image, as in a black and white photograph. 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 automatically. pgmtoppm is for colorizing a pgm file. Also, see ppmtorgb3 for a different way of converting color to gray. And ppmdist generates a grayscale image from a color image, but in a way that makes it easy to differentiate the original colors, not necessarily a way that looks like a black and white photograph.
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),ppmdist(1),ppm(5),pgm(5)AUTHOR¶
Copyright (C) 1989 by Jef Poskanzer.| 10 April 2000 |