RGB channel extraction problem

I have a question. I have an image that is 1024*1024*3 but when I extract it using :

red=image(1,:,:);
green=image(:,1,:);
blue=image(:,:,1);

then size of red is 1*1024*3, green is 1024*1*3 and blue is 1024*1024. What is wrong with green and red channel why I am not getting a right result and how can I extract their channel?

Answer 1

[Geoff Hayes]

chess - to extract the correct channel, you have to remember that it is the third dimension that indicates colour. So if img is your 1024x1024x3 image, then

 red   = img(:,:,1);  % 1 for red
 green = img(:,:,2);  % 2 for green
 blue  = img(:,:,3);  % 3 for blue

Remember that image is a built-in MATLAB function, and so is not a good name for a local variable.

[chess]

Thanks I can't believe what I just asked.