Mahotas is an Image Processing Library for Python.
It includes a couple of algorithms implemented in C++ for speed while
operating in numpy arrays.

Notable algorithms:
 - watershed.
 - thresholding.
 - convex points calculations.
 - hit & miss. thinning.
 - Zernike & Haralick features.
 - freeimage based numpy image loading (requires freeimage libraries
to be installed).
 - Release the GIL in morphological functions
 - Convolution

WWW: http://packages.python.org/mahotas/