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comparison scripts/image/rgb2ind.m @ 15683:806ea52af230

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Overhaul m-files in image directory to provide better support for images stored as integers. * NEWS: Add note about overhaul of image scripts to support integer classes. * brighten.m: Add demo. * colormap.m: Better input validation. * contrast.m: Re-position window in demo. * gray2ind.m: Redo docstring. Match variables in docstring to function prototype. Better input validation. Return integer class outputs as Matlab does. Add %!tests. * hsv2rgb.m: Add to docstring. Better input validation. Redo algorithm to get rido of obsolete matrix-fill methods like kron(). Add %!tests. * image.m: Redo docstring. Match variables in docstring to function prototype. Better input validation without using for loops. * imagesc.m: Redo docstring. Match variables in docstring to function prototype. Remove DEPRECATEDZOOM functionality. Add demos. * imfinfo.m: Redo docstring. * ind2gray.m: Redo docstring. Match variables in docstring to function prototype. Redo algorithm to directly calculate luminance value rather than getting it from rgb2ntsc. Add %!tests. * ind2rgb.m: Redo docstring. Better input validation. Add some %!tests. * ntsc2rgb.m: Redo docstring. Better input validation. Add %!tests. * rgb2hsv.m: Better input validation. Add %!tests. * rgb2ind.m: Better input validation. Code algorithm in cleaner method for ease of understanding. * rgb2ntsc.m: Redo docstring: Better input validation. Add some %!tests.
author Rik <rik@octave.org>
date Tue, 27 Nov 2012 16:38:13 -0800
parents 1f911333ed3d
children a1b634240352
comparison
equal deleted inserted replaced
15682:48e3841a7510 15683:806ea52af230
22 ## Convert an image in red-green-blue (RGB) space to an indexed image. 22 ## Convert an image in red-green-blue (RGB) space to an indexed image.
23 ## @seealso{ind2rgb, rgb2hsv, rgb2ntsc} 23 ## @seealso{ind2rgb, rgb2hsv, rgb2ntsc}
24 ## @end deftypefn 24 ## @end deftypefn
25 25
26 ## Bugs: The color map may have duplicate entries. 26 ## Bugs: The color map may have duplicate entries.
27 27 ## FIXME: This function has a very different syntax than the Matlab one of the same name.
28 ## Octave function does no support N, MAP, DITHER, or TOL arguments
28 ## Author: Tony Richardson <arichard@stark.cc.oh.us> 29 ## Author: Tony Richardson <arichard@stark.cc.oh.us>
29 ## Created: July 1994 30 ## Created: July 1994
30 ## Adapted-By: jwe 31 ## Adapted-By: jwe
31 32
32 function [x, map] = rgb2ind (R, G, B) 33 function [x, map] = rgb2ind (R, G, B)
35 print_usage (); 36 print_usage ();
36 endif 37 endif
37 38
38 if (nargin == 1) 39 if (nargin == 1)
39 rgb = R; 40 rgb = R;
40 if (length (size (rgb)) == 3 && size (rgb, 3) == 3) 41 if (ndims (rgb) != 3 || size (rgb, 3) != 3)
42 error ("rgb2ind: argument is not an RGB image");
43 else
41 R = rgb(:,:,1); 44 R = rgb(:,:,1);
42 G = rgb(:,:,2); 45 G = rgb(:,:,2);
43 B = rgb(:,:,3); 46 B = rgb(:,:,3);
44 else
45 error ("rgb2ind: argument is not an RGB image");
46 endif 47 endif
48 elseif (! size_equal (R, G, B))
49 error ("rgb2ind: R, G, and B must have the same size");
47 endif 50 endif
48 51
49 if (! size_equal (R, G) || ! size_equal (R, B)) 52 x = reshape (1:numel (R), size (R));
50 error ("rgb2ind: arguments must all have the same size");
51 endif
52 53
53 [hi, wi] = size (R); 54 map = [R(:), G(:), B(:)];
54
55 x = zeros (hi, wi);
56
57 map = zeros (hi*wi, 3);
58
59 map(:,1) = R(:);
60 map(:,2) = G(:);
61 map(:,3) = B(:);
62
63 x(:) = 1:(hi*wi);
64 55
65 endfunction 56 endfunction
57
58
59 %% FIXME: Need some functional tests or %!demo blocks
60
61 %% Test input validation
62 %!error rgb2ind ()
63 %!error rgb2ind (1,2)
64 %!error rgb2ind (1,2,3,4)
65