ppmcolormask

ppmcolormask(1)             General Commands Manual            ppmcolormask(1)

NAME
       ppmcolormask - produce mask of areas of a certain color in a PPM file

SYNOPSIS
       ppmcolormask 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 every-
       where 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 con-
       vert 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 hexadecimal num-
              ber: #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 be-
              tween 0 and 1.  (This style was added before MIT  came  up  with
              the similar rgbi style.)

SEE ALSO
       pgmtoppm(1), pnmcomp(1), pbmmask(1), ppm(5)

AUTHOR
       Bryan Henderson (bryanh@giraffe-data.com)

                                 14 April 2000                 ppmcolormask(1)