Mercurial > octave-dspies
view scripts/image/ind2gray.m @ 15689:14b7679891dd
ind2sub ind2gray: merge common code in private function, expanding fix for images when integers, input check, and expansion of colormap to ind2gray.
author | Carnë Draug <carandraug+dev@gmail.com> |
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date | Mon, 12 Nov 2012 04:53:42 +0000 |
parents | 1f911333ed3d |
children | a1b634240352 |
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## 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} {} ind2gray (@var{x}) ## @deftypefnx {Function File} {} ind2gray (@var{x}, @var{map}) ## Convert a color indexed image to a gray scale intensity image. ## If the colormap doesn't contain enough colors, pad it with the ## last color in the map. ## If @var{map} is omitted, the current colormap is used to determine the ## intensities. ## @seealso{gray2ind, ind2rgb} ## @end deftypefn ## Author: Tony Richardson <arichard@stark.cc.oh.us> ## Created: July 1994 ## Adapted-By: jwe function y = ind2gray (x, map) ## Do we have the right number of inputs? if (nargin < 1 || nargin > 2) print_usage (); elseif (nargin == 1) map = colormap (); endif [x, map] = ind2x ("ind2gray", x, map); ## Convert colormap to intensity values (the first column of the ## result of the call to rgb2ntsc) and then replace indices in ## the input matrix with indexed values in the output matrix (indexed ## values are the result of indexing the intensity values by the ## elements of x(:)). y = reshape (((rgb2ntsc (map))(:,1))(x(:)), rows (x), columns (x)); endfunction