Regions of similarity in a matrix

[Daniel Pryde]

Hi again everyone.

I was wondering if anyone knew of any python modules that are able to 
detect and extract regions of similarity from a matrix. My problem is 
that I have a self organizing map that has been trained, but now need to 
detect and extract the areas that contain similar values. In my case, 
each matrix point contains 9 pixels. I have calculated the euclidean 
values for each 9 pixel tuple in order to search for edges, so I'm 
guessing that an edge would just be a radical change between 
neighbouring values. I'm pretty sure that I'll be able to code it up 
myself, but was just asking in the hope that a module may already exist 
to help me along the way. :)

Any help would be greatly appreciated.

Daniel