rgb to ycbcr conversion in matlab

Question

I am trying to write a function in Matlab that takes an RGB image of class unit8 and double and converts it to a YCBCR image. The transformation formula is below.

Answer 1

"rgb2ycbcr" function (image processing toolbox):

Path :

MATLAB\R2013a\toolbox\images\colorspaces\rgb2ycbcr.m

Code :

function ycbcr = rgb2ycbcr(varargin)
rgb = parse_inputs(varargin{:});
isColormap = false;

if (ndims(rgb) == 2)
 isColormap=true;
 colors = size(rgb,1);
 rgb = reshape(rgb, [colors 1 3]);
end

origT = [65.481 128.553 24.966;-37.797 -74.203 112; 112 -93.786 -18.214];
origOffset = [16;128;128];


scaleFactor.double.T = 1/255;      
scaleFactor.double.offset = 1/255; 
scaleFactor.uint8.T = 1/255;       
scaleFactor.uint8.offset = 1;      
scaleFactor.uint16.T = 257/65535;  
scaleFactor.uint16.offset = 257;   

classIn = class(rgb);
T = scaleFactor.(classIn).T * origT;
offset = scaleFactor.(classIn).offset * origOffset;


ycbcr = zeros(size(rgb),classIn);

for p = 1:3
 ycbcr(:,:,p) = imlincomb(T(p,1),rgb(:,:,1),T(p,2),rgb(:,:,2), T(p,3),rgb(:,:,3),offset(p));
end  

if isColormap
 ycbcr = reshape(ycbcr, [colors 3 1]);
end