Mahotas is an image processing library for Python. It includes a couple of algorithms implemented in C++ for speed while operating in numpy arrays. The main algorithms are watershed and Otsu thresholding.
PostPic is an extension for the PostgreSQL DBMS that enables image processing inside the database, like PostGIS does for spatial data. It adds a new ‘image’ type to the SQL and several functions for processing images and extracting their attributes.