Golan Levin has written an excellent introduction to computer vision for artists and designers.

cut-n-pasted from the introduction:

“The first section of this article introduces some of the ways in which computer vision has found artistic applications outside of industrial and military research. Section II, Elementary Computer Vision Techniques, presents an overview of several basic but widely-used vision algorithms, with example code included in appendices at the end of the article. Although it is easy to suppose that sophisticated software is all one needs to create a computer vision system, Section III, Computer Vision in the Physical World, makes the case that a well-prepared physical environment can dramatically improve algorithmic performance and robustness. The remaining sections present a brief survey of several artist-friendly new computer vision toolkits, and an example of a student project, developed by novice programmers in a workshop structured around the considerations presented in this article.”