Image:Barns grand tetons HSV separation.jpg

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[edit] Summary

This takes an image (Image:Barns grand tetons.jpg) and displays the H, S and V elements of it.

Note that the H element is the only one displaying colour. Compare the dark on the left side of the barn roof and the white of the snow; in both cases these have colour, but the saturation is very low, causing them to be near-greyscale; the intensity of the barn is much lower than the snow. The green of the grass is highly saturated and of moderate intensity; the blue of the mountains is consistent in colour but varies in intensity and saturation; and the sky has constant colour and intensity but varying saturation.

[edit] Generator code

In MATLAB:

RGBimage = imread('barns_grand_tetons_reduced.jpg');
[height,width,depth]=size(RGBimage);
HSVimage=rgb2hsv(RGBimage);

% Caution: MATLAB's hsv2rgb routine is very memory-hungry. I had to halve
% the size of the source image to avoid running out or memory (even with
% a lot of swap space allocated).

% Newer versions of matlab need outputimage=zeros(height*4,width,depth,'double');
outputimage=double(zeros(height*4,width,depth));
for w=1:width,
  for h=1:height,
    outputimage(h,w,1) = HSVimage(h,w,1); %Copy H, S and V for normal image
    outputimage(h,w,2) = HSVimage(h,w,2);
    outputimage(h,w,3) = HSVimage(h,w,3);
    outputimage(h+height,w,1) = HSVimage(h,w,1); %Copy H only for first component
    outputimage(h+height,w,2) = 1;
    outputimage(h+height,w,3) = 1;
    outputimage(h+(2*height),w,2) = HSVimage(h,w,2); %S only for second component
    outputimage(h+(2*height),w,1) = 1;
    outputimage(h+(2*height),w,3) = 1;
    outputimage(h+(3*height),w,3) = HSVimage(h,w,3); %V only for third component
    outputimage(h+(3*height),w,1) = 1;
    outputimage(h+(3*height),w,2) = 1;
  end
end

im2=hsv2rgb(outputimage);
image(im2);
imwrite(im2,'HSV_separation.jpg','jpeg');

[edit] Licensing

Based on the (public domain) photo Image:Barns grand tetons.jpg. Code above and resulting output by Mike1024.

This image is copyrighted. However, the copyright holder has irrevocably released all rights to it, allowing it to be freely reproduced, distributed, transmitted, used, modified, built upon, or otherwise exploited in any way by anyone for any purpose, commercial or non-commercial, with or without attribution of the author, as if in the public domain.

File history

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(del) (cur) 17:47, 2 June 2006 . . Mike1024 (Talk | contribs) . . 800×2392 (369,530 bytes) (==Summary== This takes an image (Image:Barns grand tetons.jpg) and displays the H, S and V elements of it. Note that the H element is the only one displaying colour. Compare the dark on the left side of the barn roof and)