ABSTRACT
FACES ARE a very interesting application of pattern theory ideas. The difficultyin modeling faces is the extraordinary number of variables affecting their appearance: (a) changes in illumination; (b) changes in viewing angle; (c) varying expressions, (d) varying appearance between individuals; and (e) partial occlusion by hair, glasses, or other factors. The variations (a), (b), (c), and (e) are eliminated in Figure 5.1, so you can see how great the remaining factor, (d), is.
