1 ## Copyright (C) 2000 Etienne Grossmann
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.
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.
13 ## You should have received a copy of the GNU General Public License
14 ## along with this program; If not, see <http://www.gnu.org/licenses/>.
17 ## @deftypefn {Function File} {@var{b} = } bwborder (@var{im})
18 ## Finds the borders of foreground objects in a binary image.
20 ## @var{b} is the borders in the 0-1 matrix @var{im}. 4-neighborhood is considered.
22 ## A pixel is on the border if it is set in @var{im}, and it has at least one
23 ## neighbor that is not set.
26 ## Author: Etienne Grossmann <etienne@cs.uky.edu>
27 ## Last modified: January 2000
29 function b = bwborder(im)
34 !([im(2:R,:) ; zeros(1,C) ] & ...
35 [zeros(1,C); im(1:R-1,:) ] & ...
36 [im(:,2:C) , zeros(R,1) ] & ...
37 [zeros(R,1), im(:,1:C-1)] ) ;