ppmcolormask(1)ppmcolormask(1)NAMEppmcolormask - produce mask of areas of a certain color in
a PPM file
SYNOPSISppmcolormask color [ppmfile]
DESCRIPTION
Reads a PPM file as input. Produces a PBM (bitmap) file
as output. The output file is the same dimensions as the
input file and is black in all places where the input file
is the color color, and white everywhere else.
The output of ppmcolormask is useful as an alpha mask
input to pnmcomp. Note that you can generate such an
alpha mask automatically as you convert to PNG format with
pnmtopng(1). Use its -transparent option.
ppmfile is the input file. If you don't specify ppmfile,
the input is from Standard Input.
The output goes to Standard Output.
You can specify color five ways:
o An X11-style color name (e.g. black).
o An X11-style hexadecimal specifier: rgb:r/g/b,
where r g and b are each 1- to 4-digit hexadecimal
numbers.
o An X11-style decimal specifier: rgbi:r/g/b, where r
g and b are floating point numbers between 0 and 1.
o For backwards compatibility, an old-X11-style hex
adecimal number: #rgb, #rrggbb, #rrrgggbbb, or
#rrrrggggbbbb.
o For backwards compatibility, a triplet of numbers
separated by commas: r,g,b, where r g and b are
floating point numbers between 0 and 1. (This
style was added before MIT came up with the similar
rgbi style.)
SEE ALSOpgmtoppm(1), pnmcomp(1), pbmmask(1), ppm(5)AUTHOR
Bryan Henderson (bryanh@giraffe-data.com)
14 April 2000 ppmcolormask(1)
