[Image-SIG] Feature recognition in Python?

[Alex Cobb]

Hi everyone,

	I am working on a (very) simple feature recognition task:  finding 
light-colored ellipses on a dark background.  Has anyone seen any code/know 
of any resources for feature recognition using Python?
	More detail, if you want it:  I am working on an algorithm that would 
determine whether any given pixel represented the center of an ellipse by 
determining whether it is the centroid of pixel values in a neighborhood of 
a given radius.  I've gotten as far as using PIL to load a .jpg, 
transferring it to a NumPy matrix using tostring and fromstring -- now I 
want to apply the filter.  Is it possible to implement custom filters like 
this in PIL?  Or am I better off doing it using NumPy?

Thanks in advance for any help --

Alex