Recent theoretical developments and research findings from three different approaches to visual perception are brought together in this book. The first approach is physiological; the evolution of different types of eye and the physiology of mammalian visual pathways are described. The second is the traditional psychological approach; perceptual organization, the perception of depth and motion, and pattern recogniton are discussed in terms of the processing of information contained in retinal images. Emphasis is placed on recent computational work on these processes, and particularly on algorithms for the detection of edges and motion, the computation of stereo disparity, and object recognition.