standard deviation and mean of image

I have an image A and its corresponding glcm matrix named GLCM. which one of the two matrices will provide me with the correct standard deviation and mean of the image?

I know what GLCM is and how it works but finding standard deviation from GLCM matrix gives a very high value. While if i find standard deviation from the image matrix itself it is a relatively smaller value. So which one of the two shows the actual standard deviation of the image? Same goes for the mean of the image.

Answer 1

[Jeff E]

I'm assuming you are interested in the mean and S.D. of the intensity in the image. In which case, you would just take the mean (mean2) and S.D. (std2) of the image.

The GLCM matrix is a measure of texture. I don't see how the GLCM would give you any meaningful information about the distribution of the pixel intensities.

If you're interested in some other measure of the image that is not intensity, you'll need to elaborate.

[farheen asdf]

yes i am talking about the image intensity. So i should use the image matrix to find mean and SD? i also wanted to know about the variance of the image. I think i should use the image matrix to find that too. Correct?

[Image Analyst]

Yes, and yes.

theVariance = var(grayImage(:));