1Ppmcolormask User Manual(0)                        Ppmcolormask User Manual(0)
2
3
4

NAME

6       ppmcolormask - produce mask of areas of a certain color in a PPM file
7
8

SYNOPSIS

10       ppmcolormask -color=color_list [ppmfile]
11
12       ppmcolormask color [ppmfile]
13
14

EXAMPLES

16           ppmcolormask -color red testimg.ppm >redmask.pbm
17           pamcomp background.ppm testimg.ppm -alpha=redmask.pbm >test.ppm
18
19           ppmcolormask -color=red,pink,salmon testimg.ppm >reddishmask.pbm
20
21           ppmcolormask -color=bk:red,bk:orange,bk:yellow testimg.ppm >firemask.pbm
22
23
24

DESCRIPTION

26       This program is part of Netpbm(1).
27
28       ppmcolormask reads a PPM file as input and produces a PBM (bitmap) file
29       as output.  The output file is the same dimensions as  the  input  file
30       and is black in all places where the input file is a color indicated by
31       the -color option, and white everywhere else.
32
33       The output of ppmcolormask is useful as a transparency  mask  input  to
34       pamcomp.   Note that you don't need ppmcolormask and pamcomp if you are
35       ultimately converting to PNG with  pnmtopng  because  the  -transparent
36       option on pnmtopng does the same thing.
37
38       ppmfile  is the input file.  If you don't specify ppmfile, the input is
39       from Standard Input.
40
41       The output goes to Standard Output.
42
43       In the obsolete alternative syntax, specifying the color names a single
44       exact color to be masked.
45
46       ppmchange does a similar thing: it modifies an image by changing colors
47       you specify to other colors you specify.  The  two  programs  give  you
48       somewhat different means of specifying colors in the input image.
49
50       To make a mask of an image's background, without having to tell it what
51       color it is, use pambackground.
52
53

OPTIONS

55       In addition to the options common to all programs  based  on  libnetpbm
56       (most notably -quiet, see
57        Common  Options  ⟨index.html#commonoptions⟩ ), ppmcolormask recognizes
58       the following command line option:
59
60
61
62       -color=color_list
63              This mandatory option specifies the colors that are to be masked
64              (where the image is one of these colors, the output mask will be
65              black).
66
67              Examples:
68
69
70
71       ·      -color=red
72
73       ·      -color=red,pink,salmon
74
75       ·      -color=rgb:80/80/ff
76
77       ·      -color=bk:red,bk:orange,bk:yellow
78
79
80              color_list is a list of colors separated by commas.  Each  color
81              is  either  an exact color name as described for the argument of
82              the          pnm_parsecolor()          library           routine
83              ⟨libnetpbm_image.html#colorname⟩  or one of the Berlin-Kay color
84              names ⟨libppm.html#berlinkay⟩ .  In the latter case, all  colors
85              that are better described by that Berlin-Kay color name than any
86              other are in the mask set.
87
88              The algorithm ppmcolormask uses to determine to which  colors  a
89              Berlin-Kay  color  name  applies is based on a Sugeno-type fuzzy
90              inference system developed by  Kenan  Kalajdzic  in  2006.   The
91              fuzzy  model  consists  of partially linear membership functions
92              defined in the HSV color space.   Although  more  complex  algo‐
93              rithms  for fuzzy color matching exist, this algorithm is inten‐
94              tionally simplified to achieve a satisfactory speed using  rela‐
95              tively compact code.
96
97              This  option  was new in Netpbm 10.34 (June 2006).  Before that,
98              you must use the color argument and cannot specify a  Berlin-Kay
99              color.
100
101
102
103

SEE ALSO

105       pamfind(1),  pambackground(1),  ppmchange(1),  pgmtoppm(1), pamcomp(1),
106       pbmmask(1), pnmtopng(1), ppm(1)
107

DOCUMENT SOURCE

109       This manual page was generated by the Netpbm tool 'makeman'  from  HTML
110       source.  The master documentation is at
111
112              http://netpbm.sourceforge.net/doc/ppmcolormask.html
113
114netpbm documentation              01 May 2006      Ppmcolormask User Manual(0)