how to extract Y channel from YCuCv image?

I have a project named "Hierarchical Prediction and Context Adaptive Coding for Lossless Colour Image Compression". for that we need to convert image from RGB into YCuCv model by using RCT,and we have to extract "y" component from that YCuCv model.How do to it?

Answer 1

[Thorsten]

See https://en.wikipedia.org/wiki/JPEG_2000#Color_components_transformation

 I = imread('peppers.png'); 
 R = I(:,:,1); G = I(:,:,2); B = I(:,:,3);
 Y = floor((R + 2*G + B)/4);
 Cb = B - G;
 Cr = R - G;