Mercurial > octave-antonio
view scripts/image/flag.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 | 1a800034d443 |
children | d63878346099 |
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## Copyright (C) 1999-2012 Kai Habel ## ## 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{map} =} flag () ## @deftypefnx {Function File} {@var{map} =} flag (@var{n}) ## Create color colormap. This colormap cycles through red, white, blue, ## and black with each index change. ## The argument @var{n} must be a scalar. ## If unspecified, the length of the current colormap, or 64, is used. ## @seealso{colormap} ## @end deftypefn ## Author: Kai Habel <kai.habel@gmx.de> ## PKG_ADD: colormap ("register", "flag"); ## PKG_DEL: colormap ("unregister", "flag"); function map = flag (n) if (nargin == 0) n = rows (colormap); elseif (nargin == 1) if (! isscalar (n)) error ("flag: N must be a scalar"); endif else print_usage (); endif if (n == 1) map = [1, 0, 0]; elseif (n > 1) C = [1, 0, 0; 1, 1, 1; 0, 0, 1; 0, 0, 0]; map = C(rem (0:(n-1), 4) + 1, :); else map = zeros (0, 3); endif endfunction %!demo %! ## Show the 'flag' colormap as an image %! image (1:64, linspace (0, 1, 64), repmat ((1:64)', 1, 64)); %! axis ([1, 64, 0, 1], "ticy", "xy"); %! colormap (flag (64));