Let's begin with the picture on the front cover. You may have observed that the portra让of Alan Turing is constructed from a number of pictures ("tiles") of great computer scientists and mathematicians. Suppose you were asked in an interview to design a program that takes an 垃nage and a collection of s x s-sized tiles and produce a mosaic from the tiles that resembles the image. A good way to begin may be to partition the image into s x s-sized squares, compute the average color of each such image square, and then find the tile that is closest to it in the color space. Here distance in.
