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

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

       ppmcolormask -color=color_list [ppmfile]

       ppmcolormask color [ppmfile]

	   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

       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 a transparency  mask  input  to
       pamcomp.	  Note that you	don't need ppmcolormask	and pamcomp if you are
       ultimately converting to	PNG with pnmtopng because the -transparent op-
       tion on pnmtopng	does the same thing.

       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.

	      This mandatory option specifies the colors that are to be	masked
	      (where the image is one of these colors, the output mask will be


       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	   pnm_parsecolor()	     library	       routine
	      <libnetpbm_image.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

       pamfind(1),  pambackground(1),  ppmchange(1),  pgmtoppm(1), pamcomp(1),
       pbmmask(1), pnmtopng(1),	ppm(5)

       This manual page	was generated by the Netpbm tool 'makeman'  from  HTML
       source.	The master documentation is at

netpbm documentation		  1 May	2006	   Ppmcolormask	User Manual(0)


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