ntsc2rgb - Converts from YIQ to RGB colorspace
ntsc2rgb(YIQ) converts an YIQ image or colormap from YIQ to RGB colorspace. The YIQ model is used in NTSC and European TV's. It is useful for b&w and color compatibility, since the cromaticity (I and Q) and luminance (Y) are conveniently isolated. ntsc2rgb(YIQ) uses the following operation to convert each YIQ triplet:
! R ! ! 1.000 0.956 0.621 ! ! Y ! ! G ! = ! 1.000 -0.272 -0.647 ! * ! I ! ! B ! ! 1.000 -1.105 1.702 ! ! Q !
initial_dir = PWD; chdir (SIPDIR + 'images'); rgb = imread('tru.jpg'); // RGB colorspace 0-1 imshow(rgb); yiq = rgb2ntsc(rgb); // YIQ colorspace 0-1 yiq(:,:,2) = yiq(:,:,2) /4; // Decrease chromaticity yiq(:,:,3) = yiq(:,:,3) /4; rgb = ntsc2rgb(yiq); imshow(rgb); chdir(initial_dir);
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