xenial (1) ppmcolormask.1.gz

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 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 hexadecimal 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 ALSO

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

AUTHOR

       Bryan Henderson (bryanh@giraffe-data.com)

                                                  14 April 2000                                  ppmcolormask(1)