We are visual animals. But before we can see the world in its true splendor, our brains, just like our computers, have to sort and organize raw data, and then transform that data to produce new images of the world. Beginning Python Crafting Visual Transformation Scripts discusses turning many types of small data sources into useful visual data. And, you will learn Python as part of the bargain.
I really loved this book, although I think a better title would have been "Data Analysis with Python". It certainly does walk you through some useful material about the Python Image Library (PIL), but much more is presented on Numpy and SciPy as well.
This is a very practical book if you want to do any data processing, scientific work, or simulation with Python.