ppmtorgb3(1) General Commands Manual ppmtorgb3(1)NAME
ppmtorgb3 - separate a portable pixmap into three portable graymaps
SYNOPSIS
ppmtorgb3 [ppmfile]
DESCRIPTION
Reads a portable pixmap as input. Writes three portable graymaps as output, one each for red, green, and blue.
The output filenames are constructed by taking the input filename, stripping off any extension, and appending ".red", ".grn", and ".blu".
For example, separating lenna.ppm would result in lenna.red, lenna.grn, and lenna.blu. If the input comes from stdin, the names are no-
name.red, noname.grn, and noname.blu.
SEE ALSO rgb3toppm(1), ppmtopgm(1), pgmtoppm(1), ppm(5), pgm(5)AUTHOR
Copyright (C) 1991 by Jef Poskanzer.
10 January 1991 ppmtorgb3(1)
Check Out this Related Man Page
ppmtopgm(1) General Commands Manual 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 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 ppmtopgm(1)
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