--- /dev/null
+## Copyright (C) 2008 Soren Hauberg
+##
+## This program is free software; you can redistribute it and/or
+## modify it under the terms of the GNU General Public License
+## as published by the Free Software Foundation; either version 2
+## of the License, or (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+## GNU General Public License for more details.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} @var{bw2} = bwhitmiss (@var{bw1}, @var{se1}, @var{se1})
+## @deftypefnx{Function File} @var{bw2} = bwhitmiss (@var{bw1}, @var{interval})
+## Perform the binary hit-miss operation.
+##
+## If two structuring elements @var{se1} and @var{se1} are given, the hit-miss
+## operation is defined as
+## @example
+## bw2 = erode(bw1, se1) & erode(!bw1, se2);
+## @end example
+## If instead an 'interval' array is given, two structuring elements are computed
+## as
+## @example
+## se1 = (interval == 1)
+## se2 = (interval == -1)
+## @end example
+## and then the operation is defined as previously.
+## @seealso{bwmorph}
+## @end deftypefn
+
+function bw = bwhitmiss(im, varargin)
+ ## Checkinput
+ if (nargin != 2 && nargin != 3)
+ print_usage();
+ endif
+ if (!ismatrix(im) || !isreal(im))
+ error("bwhitmiss: first input argument must be a real matrix");
+ endif
+
+ ## Get structuring elements
+ if (nargin == 2) # bwhitmiss (im, interval)
+ interval = varargin{1};
+ if (!isreal(interval))
+ error("bwhitmiss: second input argument must be a real matrix");
+ endif
+ if (!all( (interval(:) == 1) | (interval(:) == 0) | (interval(:) == -1) ))
+ error("bwhitmiss: second input argument can only contain the values -1, 0, and 1");
+ endif
+ se1 = (interval == 1);
+ se2 = (interval == -1);
+ else # bwhitmiss (im, se1, se2)
+ se1 = varargin{1};
+ se2 = varargin{2};
+ if (!all((se1(:) == 1) | (se1(:) == 0)) || !all((se2(:) == 1) | (se2(:) == 0)))
+ error("bwhitmiss: structuring elements can only contain zeros and ones.");
+ endif
+ endif
+
+ ## Perform filtering
+ bw = erode(im, se1) & erode(!im, se2);
+
+endfunction