Section: User Commands (1)
Updated: 6 January 1997
pngtopnm [-verbose] [-alpha | -mix] [-background color]
Reads a Portable Network Graphics as input. ]] Produces a portable anymap as output. The type of the output file depends on the input file - if it's black & white, a pbm file is written, else if it's grayscale a pgm file, else a ppm file.
Because the gamma's of uncompensated monitors are around 2.6, which results in an image-gamma of 0.45, some typical situations are: when the image-gamma is 0.45 (use -verbose to check) and the picture is too light, your system is gamma-corrected, so convert with "-gamma 1.0". When no gAMA chunk is present or the image-gamma is 1.0, use 2.2 to make the picture lighter and 0.45 to make the picture darker.:
There could be an option to read the comment text from pnm comments instead of a separate file.
Copyright (C) 1995-1997 by Alexander Lehmann
and Willem van Schaik.
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