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comparison main/image/im2bw.m @ 0:6b33357c7561 octave-forge

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Initial revision
author pkienzle
date Wed, 10 Oct 2001 19:54:49 +0000
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-1:000000000000 0:6b33357c7561
1 ## Copyright (C) 2000 Kai Habel
2 ##
3 ## This program is free software; you can redistribute it and/or modify
4 ## it under the terms of the GNU General Public License as published by
5 ## the Free Software Foundation; either version 2 of the License, or
6 ## (at your option) any later version.
7 ##
8 ## This program is distributed in the hope that it will be useful,
9 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
10 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 ## GNU General Public License for more details.
12 ##
13 ## You should have received a copy of the GNU General Public License
14 ## along with this program; if not, write to the Free Software
15 ## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16
17 ## -*- texinfo -*-
18 ## @deftypefn {Function File} @var{BW}= im2bw (@var{I},threshold)
19 ## @deftypefnx {Function File} @var{BW}= im2bw (@var{X},@var{cmap},threshold)
20 ## converts image data types to a black-white (binary) image.
21 ## The treshold value should be in the range [0,1].
22 ## @end deftypefn
23
24 ## Author: Kai Habel <kai.habel@gmx.de>
25 ## Date: 19. March 2000
26
27 function BW = im2bw (img, a, b)
28
29 if ( nargin < 2 || nargin > 3)
30 usage("im2bw(I) number of arguments must be 2 or 3");
31 endif
32
33 if (isgray (img))
34 if (is_scalar (a))
35 BW = (img >= a);
36 else
37 error ("threshold value must be scalar");
38 endif
39 elseif (isind (img))
40 if (is_matrix (a) && columns (a) == 3)
41 if (is_scalar (b))
42 I = ind2gray (img, a);
43 BW = (I >= b);
44 endif
45 endif
46 else
47 error ("image matrix must be of index or intensity type");
48 endif
49
50 endfunction