ppmcolormask(1) - man - phpman

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 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 AT giraffe-data.com)




                                            14 April 2000                            ppmcolormask(1)