Ppmcolormask User Manual(0)			   Ppmcolormask User Manual(0)



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


SYNOPSIS
       ppmcolormask -color=color_list [ppmfile]

       ppmcolormask color [ppmfile]


EXAMPLES
	   ppmcolormask -color red testimg.ppm >redmask.pbm
	   pamcomp background.ppm testimg.ppm -alpha=redmask.pbm >test.ppm

	   ppmcolormask -color=red,pink,salmon testimg.ppm >reddishmask.pbm

	   ppmcolormask -color=bk:red,bk:orange,bk:yellow testimg.ppm >firemask.pbm



DESCRIPTION
       This program is part of Netpbm(1).

       ppmcolormask reads a PPM file as input and 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 a color indicated by
       the -color option, and white everywhere else.

       The output of ppmcolormask is useful as an alpha mask input to pamcomp.
       Note that you can generate such an alpha mask automatically as you con-
       vert to PNG format with pnmtopng(1).Useits-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.

       In the obsolete alternative syntax, specifying the color names a single
       exact color to be masked.

       ppmchange does a similar thing: it modifies an image by changing colors
       you  specify  to	 other	colors you specify.  The two programs give you
       somewhat different means of specifying colors in the input image.

       To make a mask of an image's background, without having to tell it what
       color it is, use pambackground.


OPTIONS
       -color=color_list
	      This mandatory option specifies the colors that are to be masked
	      (where the image is one of these colors, the output mask will be
	      black).

	      Examples:



       o      -color=red

       o      -color=red,pink,salmon

       o      -color=rgb:80/80/ff

       o      -color=bk:red,bk:orange,bk:yellow


	      color_list  is a list of colors separated by commas.  Each color
	      is either an exact color name as described for the  argument  of
	      the ppm_parsecolor() library routine <libppm.html#colorname>  or
	      one of the Berlin-Kay color names <libppm.html#berlinkay> .   In
	      the  latter  case,  all colors that are better described by that
	      Berlin-Kay color name than any other are in the mask set.

	      The algorithm ppmcolormask uses to determine to which  colors  a
	      Berlin-Kay  color	 name  applies is based on a Sugeno-type fuzzy
	      inference system developed by  Kenan  Kalajdzic  in  2006.   The
	      fuzzy  model  consists  of partially linear membership functions
	      defined in the HSV color space.	Although  more	complex	 algo-
	      rithms  for fuzzy color matching exist, this algorithm is inten-
	      tionally simplified to achieve a satisfactory speed using	 rela-
	      tively compact code.

	      This  option  was new in Netpbm 10.34 (June 2006).  Before that,
	      you must use the color argument and cannot specify a  Berlin-Kay
	      color.




SEE ALSO
       pambackground(1),  ppmchange(1),	 pgmtoppm(1),  pamcomp(1), pbmmask(1),
       ppm(1)



netpbm documentation		  1 May 2006	   Ppmcolormask User Manual(0)