Vision is our dominant sense. We derive most of our information about the world - about where things are, how they move and what they are - from the light that enters the eye and the processing in the brain that follows. Yet, despite the fact that we know more about vision than any other sense, we still do not understand how these functions are performed. The starting point of this study is the function that vision serves for an active observer in the three-dimensional environment. Thus the perception of location, motion and object recognition form the core of the book. The machinery of vision is also described. "Visual Perception" places the study of vision in its historical context, since our ideas have been shaped by art, optics, biology and philosophy as well as psychology.