Mercurial > octave
view scripts/image/rgb2hsv.m @ 21580:ecce63c99c3f
maint: Add semicolons to terminate code in %! blocks.
* splineimages.m, Cell.cc, bsxfun.cc, cellfun.cc, conv2.cc, data.cc,
debug.cc, file-io.cc, gcd.cc, getrusage.cc, graphics.cc, kron.cc, mappers.cc,
oct-map.cc, ordschur.cc, psi.cc, rand.cc, variables.cc, __osmesa_print__.cc,
amd.cc, audiodevinfo.cc, dmperm.cc, qr.cc, ov-bool-mat.cc, ov-class.cc,
ov-fcn-handle.cc, ov-java.cc, oct-parse.in.yy, bicubic.m, delaunay3.m,
accumarray.m, flip.m, fliplr.m, flipud.m, gradient.m, inputParser.m, interp1.m,
narginchk.m, rot90.m, validateattributes.m, delaunay.m, delaunayn.m,
griddata3.m, inpolygon.m, waitbar.m, gray2ind.m, hsv2rgb.m, im2double.m,
image.m, imformats.m, imread.m, imshow.m, imwrite.m, ntsc2rgb.m, rgb2hsv.m,
rgb2ntsc.m, isbanded.m, onenormest.m, edit.m, fullfile.m, license.m, ode23.m,
ode45.m, glpk.m, annotation.m, legend.m, orient.m, text.m, area.m, barh.m,
contour.m, line.m, plot.m, plot3.m, plotyy.m, quiver.m, stem.m, clf.m,
copyobj.m, findobj.m, subplot.m, ppval.m, splinefit.m, ismember.m, freqz.m,
unwrap.m, eigs.m, ichol.m, pcg.m, spdiags.m, svds.m, magic.m, lscov.m,
median.m, ols.m, dec2base.m, strsplit.m, strtok.m, test.m, bug-31371.tst,
bug-36025.tst, bug-44940.tst, build-sparse-tests.sh, class-concat.tst,
classdef.tst, classes.tst, colormaps.tst, command.tst, ctor-vs-method.tst,
error.tst, fcn-handle-derived-resolution.tst, for.tst, index.tst, io.tst,
jit.tst, null-assign.tst, parser.tst, struct.tst, system.tst:
Add semicolons to terminate code in %! blocks.
author | Rik <rik@octave.org> |
---|---|
date | Fri, 01 Apr 2016 16:03:29 -0700 |
parents | acd6e203031d |
children | b002b4331a12 |
line wrap: on
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## Copyright (C) 1999-2015 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{hsv_map} =} rgb2hsv (@var{rgb}) ## @deftypefnx {} {@var{hsv_map} =} rgb2hsv (@var{rgb}) ## Transform a colormap or image from RGB to HSV color space. ## ## A color in the RGB space consists of red, green, and blue intensities. ## ## A color in HSV space is represented by hue, saturation and value ## (brightness) levels in a cylindrical coordinate system. Hue is the ## azimuth and describes the dominant color. Saturation is the radial ## distance and gives the amount of hue mixed into the color. Value is ## the height and is the amount of light in the color. ## ## Output class and size will be the same as input. ## ## @seealso{hsv2rgb, rgb2ind, rgb2ntsc} ## @end deftypefn ## Author: Kai Habel <kai.habel@gmx.de> ## Adapted-by: jwe function hsv = rgb2hsv (rgb) if (nargin != 1) print_usage (); endif [rgb, sz, is_im, is_nd] ... = colorspace_conversion_input_check ("rgb2hsv", "RGB", rgb); ## get the max and min for each row s = min (rgb, [], 2); v = max (rgb, [], 2); ## set hue to zero for undefined values (gray has no hue) h = zeros (rows (rgb), 1); notgray = (s != v); ## blue hue idx = (v == rgb(:,3) & notgray); if (any (idx)) h(idx) = 2/3 + 1/6 * (rgb(idx,1) - rgb(idx,2)) ./ (v(idx) - s(idx)); endif ## green hue idx = (v == rgb(:,2) & notgray); if (any (idx)) h(idx) = 1/3 + 1/6 * (rgb(idx,3) - rgb(idx,1)) ./ (v(idx) - s(idx)); endif ## red hue idx = (v == rgb(:,1) & notgray); if (any (idx)) h(idx) = 1/6 * (rgb(idx,2) - rgb(idx,3)) ./ (v(idx) - s(idx)); endif h(h < 0) += 1; # correct for negative red ## set the saturation s(! notgray) = 0; s(notgray) = 1 - s(notgray) ./ v(notgray); hsv = [h, s, v]; hsv = colorspace_conversion_revert (hsv, sz, is_im, is_nd); endfunction ## Test pure colors and gray %!assert (rgb2hsv ([1 0 0]), [0 1 1]) %!assert (rgb2hsv ([0 1 0]), [1/3 1 1]) %!assert (rgb2hsv ([0 0 1]), [2/3 1 1]) %!assert (rgb2hsv ([1 1 0]), [1/6 1 1]) %!assert (rgb2hsv ([0 1 1]), [1/2 1 1]) %!assert (rgb2hsv ([1 0 1]), [5/6 1 1]) %!assert (rgb2hsv ([0.5 0.5 0.5]), [0 0 0.5]) ## Test tolarant input checking on floats %!assert (rgb2hsv ([1.5 1 1]), [0 1/3 1.5], eps) %!test %! rgb_map = rand (64, 3); %! assert (hsv2rgb (rgb2hsv (rgb_map)), rgb_map, 1e-6); %!test %! rgb_img = rand (64, 64, 3); %! assert (hsv2rgb (rgb2hsv (rgb_img)), rgb_img, 1e-6); ## support sparse input %!assert (rgb2hsv (sparse ([0 0 1])), sparse ([2/3 1 1])) %!assert (rgb2hsv (sparse ([0 1 1])), sparse ([1/2 1 1])) %!assert (rgb2hsv (sparse ([1 1 1])), sparse ([0 0 1])) ## Test input validation %!error rgb2hsv () %!error rgb2hsv (1,2) %!error <invalid data type 'cell'> rgb2hsv ({1}) %!error <RGB must be a colormap or RGB image> rgb2hsv (ones (2,2)) ## Test ND input %!test %! rgb = rand (16, 16, 3, 5); %! hsv = zeros (size (rgb)); %! for i = 1:5 %! hsv(:,:,:,i) = rgb2hsv (rgb(:,:,:,i)); %! endfor %! assert (rgb2hsv (rgb), hsv); ## Test output class and size for input images. ## Most of the tests only test for colormap input. %!test %! hsv = rgb2hsv (rand (10, 10, 3)); %! assert (class (hsv), "double"); %! assert (size (hsv), [10 10 3]); %!test %! hsv = rgb2hsv (rand (10, 10, 3, "single")); %! assert (class (hsv), "single"); %! assert (size (hsv), [10 10 3]); %!test %! rgb = (rand (10, 10, 3) * 3 ) - 0.5; # values outside range [0 1] %! hsv = rgb2hsv (rgb); %! assert (class (hsv), "double"); %! assert (size (hsv), [10 10 3]); %!test %! rgb = (rand (10, 10, 3, "single") * 3 ) - 0.5; # values outside range [0 1] %! hsv = rgb2hsv (rgb); %! assert (class (hsv), "single"); %! assert (size (hsv), [10 10 3]); %!test %! hsv = rgb2hsv (randi ([0 255], 10, 10, 3, "uint8")); %! assert (class (hsv), "double"); %! assert (size (hsv), [10 10 3]); %!test %! hsv = rgb2hsv (randi ([0 65535], 10, 10, 3, "uint16")); %! assert (class (hsv), "double"); %! assert (size (hsv), [10 10 3]); %!test %! hsv = rgb2hsv (randi ([-128 127], 10, 10, 3, "int8")); %! assert (class (hsv), "double"); %! assert (size (hsv), [10 10 3]); %!test %! rgb_double = reshape ([1 0 1 .5 1 1 0 .5 0 1 1 .5], [2 2 3]); %! rgb_uint8 = reshape (uint8 ([255 0 255 128 255 255 0 128 0 255 255 128]), %! [2 2 3]); %! rgb_int16 = int16 (double (rgb_double * uint16 (65535)) -32768); %! expected = reshape ([1/6 1/2 5/6 0 1 1 1 0 1 1 1 .5], [2 2 3]); %! %! assert (rgb2hsv (rgb_double), expected); %! assert (rgb2hsv (rgb_uint8), expected, 0.005); %! assert (rgb2hsv (single (rgb_double)), single (expected));