Mercurial > octave
view scripts/image/pink.m @ 23219:3ac9f9ecfae5 stable
maint: Update copyright dates.
author | John W. Eaton <jwe@octave.org> |
---|---|
date | Wed, 22 Feb 2017 12:39:29 -0500 |
parents | bac0d6f07a3e |
children | 092078913d54 |
line wrap: on
line source
## Copyright (C) 2000-2017 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 {} {@var{map} =} pink () ## @deftypefnx {} {@var{map} =} pink (@var{n}) ## Create color colormap. This colormap varies from black to white with ## shades of gray-pink. ## ## This colormap gives a sepia tone when used on grayscale images. ## ## 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> function map = pink (n = rows (colormap ())) if (nargin > 1) print_usage (); elseif (! isscalar (n)) error ("pink: N must be a scalar"); endif if (n == 1) map = sqrt ([1/3, 1/3, 1/3]); elseif (n == 2) map = sqrt ([1/3, 1/3, 1/6 1 1 1 ]); elseif (n > 2) x = [0:(n-1)]' / (n-1); idx = floor (3/8 * n); base = 1 / (3 * idx); nel = idx; # number of elements r(1:idx,1) = linspace (base, 2/3*x(idx) + 1/3, nel); r(idx+1:n,1) = 2/3*x(idx+1:n) + 1/3; g(1:idx,1) = 2/3*x(1:idx); g(idx:2*idx,1) = linspace (2/3*x(idx), 2/3*x(2*idx) + 1/3, nel+1); g(2*idx+1:n,1) = 2/3*x(2*idx+1:n) + 1/3; nel = n - 2*idx + 1; b(1:2*idx,1) = 2/3*x(1:2*idx); b(2*idx:n,1) = linspace (2/3*x(2*idx), 1, nel); map = sqrt ([r, g, b]); else map = zeros (0, 3); endif endfunction %!demo %! ## Show the 'pink' colormap profile and as an image %! cmap = pink (256); %! subplot (2, 1, 1); %! rgbplot (cmap, "composite"); %! subplot (2, 1, 2); %! rgbplot (cmap);