Autocovariance coefficient for texture analysis

Hi I'm working with some ultrasound images and I want to extract some texture features, I have read in some papersthat the autocovariance and autocorrelation coefficients can work as texture descriptors.

How can I obtain this coefficients using Matlab. Here is the definition of the autovariance coefficient. Is there any implementation of this in Matlab?

I know there are a lot more options for texture description but right now I'm interested mainly in the autocovariance coeffcients. Here I leave a link to one of the papers using autocovariance coaffcients as texture descriptors. Texture analysis in ultrasound images

Thanks