Need to Convert RGB color space to L*U*V* color space , Please tell am i correct with this code

%convert to RgbI image in RGB to XYZ

XYZTransformation = makecform('srgb2xyz'); 

XyzI = applycform(RgbI,XYZTransformation);

%seperate X,Y,Z

X = XyzI(:,:,1);
Y = XyzI(:,:,2);
Z = XyzI(:,:,3);

figure, imshow(X) , title('X');
figure, imshow(Y) , title('Y');
figure, imshow(Z) , title('Z');

xyz = cat(3, X,Y,Z);

figure, imshow(xyz) , title('xyz');

%convert to XYZ

labTransformation = makecform('xyz2uvl');
luvI = applycform(xyz,labTransformation);

%seperate X,Y,Z

u = luvI(:,:,1);
v = luvI(:,:,2);
l = luvI(:,:,3);

figure, imshow(l) , title('l');
figure, imshow(u) , title('u');
figure, imshow(v) , title('v');

Answer 1

[Image Analyst]

Looks right to me. Just realize that any lab or luv or any other colorspace values you get from "book formulas" are not going to be the same as the "true" values you'd get from a spectrophotometer or spectroradiometer. This is because your system is not calibrated and it assumes the values are sRGB which is not true.

[rky]

Thanks for reply. So should i go with above code to calculate LUV or with formula as given in books for conversion.

Is their any other method to convert RGB color space to L*U*V* color space

[Image Analyst]

That's fine. Some more forumlas are given here: http://www.easyrgb.com/index.php?X=MATH

And expert Bruce Lindbloom has formulas here under the Math tab: http://www.brucelindbloom.com/

And one of the world's leading experts in color science, Professor Stephen Westland, has created a colour toolbox for MATLAB: http://www.mathworks.com/matlabcentral/fileexchange/?search_submit=fileexchange&query=westland&term=westland

[rky]

Thanks a lot!

[fawad khan]

Thankyou