How to find standard deviation of a RGB image?

I want to find standard deviation of a color image. How can I do ? In which std2 and std ,which one is possible to do ?or some other method is available ? Thanks in advance

Answer 1

[zepp]

std2 calculates the standard deviation of an RGB image. Look up http://uk.mathworks.com/help/images/image-mean-standard-deviation-and-correlation-coefficent.html

Answer 2

[Som]

http://in.mathworks.com/help/images/ref/std2.html