Mercurial > octave-antonio
view scripts/image/colormap.m @ 17118:c97a26408ee0
Implement PixelRegion option for imread().
* imread.m: document new option.
* private/__imread__.m: parse new option and set defaults.
* __magick_read__.cc (calculate region): new option to calculate the region
to be read, shifts in memory required, and output image size.
(read_indexed_images, read_images): implement reading of only specific
regions of an image.
(__magick_read__): get octave_scalar_map at start for simplicity.
author | Carnë Draug <carandraug@octave.org> |
---|---|
date | Wed, 31 Jul 2013 21:28:48 +0100 |
parents | 24bb7dc754ed |
children | bc924baa2c4e |
line wrap: on
line source
## Copyright (C) 1994-2012 John W. Eaton ## Copyright (C) 2012 Carnë Draug ## ## 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{cmap} =} colormap () ## @deftypefnx {Function File} {@var{cmap} =} colormap (@var{map}) ## @deftypefnx {Function File} {@var{cmap} =} colormap ("default") ## @deftypefnx {Function File} {@var{cmap} =} colormap ("list") ## @deftypefnx {Function File} {@var{cmap} =} colormap ("register", "@var{name}") ## @deftypefnx {Function File} {@var{cmap} =} colormap ("unregister", "@var{name}") ## @deftypefnx {Command} {} colormap @var{map_name} ## Query or set the current colormap. ## ## With no input arguments, @code{colormap} returns the current color map. ## ## @code{colormap (@var{map})} sets the current colormap to @var{map}. The ## colormap should be an @var{n} row by 3 column matrix. The columns ## contain red, green, and blue intensities respectively. All entries ## must be between 0 and 1 inclusive. The new colormap is returned. ## ## @code{colormap ("default")} restores the default colormap (the ## @code{jet} map with 64 entries). The default colormap is returned. ## ## @code{colormap ("list")} returns a cell array with all of the available ## colormaps. The options "register" and "unregister" will add or remove ## the colormap @var{name} from this list. ## ## For convenience, it is also possible to use this function with the ## command form, where @var{map_name} must be the name of a function ## that returns a colormap. ## ## @seealso{jet} ## @end deftypefn ## Author: Tony Richardson <arichard@stark.cc.oh.us> ## Created: July 1994 ## Adapted-By: jwe function cmap = colormap (map, name) if (nargin > 2) print_usage (); endif persistent map_list = cell (); if (nargin == 1) if (ischar (map)) if (strcmp (map, "default")) map = jet (64); elseif (strcmp (map, "list")) cmap = map_list; return; else map = feval (map); endif endif if (! isempty (map)) if (! (isnumeric (map) && isreal (map) && ndims (map) == 2 && columns (map) == 3)) error ("colormap: MAP must be a real-valued N x 3 ([R,G,B]) matrix"); endif if (any (map(:) < 0) || any (map(:) > 1)) error ("colormap: all MAP values must be in the range [0,1]"); endif ## Set the new color map set (gcf (), "colormap", map); endif elseif (nargin == 2) if (! ischar (map) || ! any (strcmp (map, {"register", "unregister"}))) print_usage (); elseif (! ischar (name)) error ("colormap: to register/unregister a colormap, NAME must be a string"); elseif (strcmp (map, "register")) map_list{end+1} = name; elseif (strcmp (map, "unregister")) map_list(strcmp (name, map_list)) = []; endif endif ## Return current color map. if (nargout > 0 || (nargout == 0 && nargin == 0)) cmap = get (gcf (), "colormap"); endif endfunction %!demo %! ## Create an image for displaying a colormap %! image (1:64, linspace (0, 1, 64), repmat ((1:64)', 1, 64)); %! axis ([1, 64, 0, 1], "ticy", "xy"); %! ## Show 'jet' colormap %! colormap (jet (64)); %! title "colormap (jet (64))" %! disp ("Press a key to continue"); %! pause (); %! ## Show 'colorcube' colormap %! colormap (colorcube (64)); %! title "colormap (colorcube (64))" %!test %! figure ("visible", "off"); %! cmaptst = [0 1 0; 1 0 1; 1 1 1]; %! cmap = colormap (cmaptst); %! assert (cmap, cmaptst); %! cmap = colormap (); %! assert (cmap, cmaptst); %! cmap = (get (gcf, "colormap")); %! assert (cmap, cmaptst); %! colormap ("default"); %! assert (colormap (), jet (64)); %! colormap ("ocean"); %! assert (colormap, ocean (64)); %! close (); # done with temp. figure %!test %! cmaplst = colormap ("list"); %! assert (iscell (cmaplst)); %! colormap ("register", "__mycmap__"); %! cmaplst2 = colormap ("list"); %! assert (numel (cmaplst2), numel (cmaplst) + 1); %! assert (any (strcmp (cmaplst2, "__mycmap__"))); %! colormap ("unregister", "__mycmap__"); %! cmaplst2 = colormap ("list"); %! assert (numel (cmaplst2), numel (cmaplst)); %! assert (! any (strcmp (cmaplst2, "__mycmap__"))); %! ## Unregister again and verify that nothing has happened %! colormap ("unregister", "__mycmap__"); %! cmaplst3 = colormap ("list"); %! assert (isequal (cmaplst2, cmaplst3)); ## Test input validation %!error colormap (1,2,3) %!error <MAP must be a real-valued N x 3> colormap ({1,2,3}) %!error <MAP must be a real-valued N x 3> colormap ([1 i 1]) %!error <MAP must be a real-valued N x 3> colormap (ones(3,3,3)) %!error <MAP must be a real-valued N x 3> colormap ([1 0 1 0]) %!error <all MAP values must be in the range> colormap ([-1 0 0]) %!error <all MAP values must be in the range> colormap ([2 0 0]) %!error colormap ("invalid", "name") %!error <NAME must be a string> colormap ("register", 1)