This is the command ppmtopgm that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
PROGRAM:
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.
Use ppmtopgm online using onworks.net services