update packages

[CreaPhase.git] / octave_packages / m / image / rgb2ind.m

diff --git a/octave_packages/m/image/rgb2ind.m b/octave_packages/m/image/rgb2ind.m
new file mode 100644 (file)
index 0000000..01067c3
--- /dev/null
+++ b/octave_packages/m/image/rgb2ind.m
@@ -0,0 +1,65 @@
+## Copyright (C) 1994-2012 John W. Eaton
+##
+## This file is part of Octave.
+##
+## Octave 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 3 of the License, or (at
+## your option) any later version.
+##
+## Octave 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.
+##
+## You should have received a copy of the GNU General Public License
+## along with Octave; see the file COPYING.  If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn  {Function File} {[@var{x}, @var{map}] =} rgb2ind (@var{rgb})
+## @deftypefnx {Function File} {[@var{x}, @var{map}] =} rgb2ind (@var{R}, @var{G}, @var{B})
+## Convert an RGB image to an Octave indexed image.
+## @seealso{ind2rgb, rgb2ntsc}
+## @end deftypefn
+
+## Bugs: The color map may have duplicate entries.
+
+## Author: Tony Richardson <arichard@stark.cc.oh.us>
+## Created: July 1994
+## Adapted-By: jwe
+
+function [x, map] = rgb2ind (R, G, B)
+
+  if (nargin != 1 && nargin != 3)
+    print_usage ();
+  endif
+
+  if (nargin == 1)
+    rgb = R;
+    if (length (size (rgb)) == 3 && size (rgb, 3) == 3)
+      R = rgb(:,:,1);
+      G = rgb(:,:,2);
+      B = rgb(:,:,3);
+    else
+      error ("rgb2ind: argument is not an RGB image");
+    endif
+  endif
+
+  if (! size_equal (R, G) || ! size_equal (R, B))
+    error ("rgb2ind: arguments must all have the same size");
+  endif
+
+  [hi, wi] = size (R);
+
+  x = zeros (hi, wi);
+
+  map = zeros (hi*wi, 3);
+
+  map(:,1) = R(:);
+  map(:,2) = G(:);
+  map(:,3) = B(:);
+
+  x(:) = 1:(hi*wi);
+
+endfunction