DISTORTIONS OF 3-DIMENSIONAL SPACE IN THE PERCEPTUAL ANALYSIS OF MOTION AND STEREO

A fundamental issue in the study of human vision is the accuracy with which observers can perceive the three-dimensional structures of objec ts in the environment. The formal mapping from physical to perceived s pace is considered as a geometric transformation, and the literature i s reviewed to identify which aspects of object structure are systemati cally distorted by this transformation and which ones remain invariant . In the perceptual analysis of several different sources of optical i nformation, including motion and stereo, both individually and in comb ination, there is a consistent pattern of results to indicate that per ceived depth intervals are scaled differently from comparable interval s in either horizontal or vertical directions. These and other finding s provide strong evidence that the relationship between physical and p erceived space is noneuclidean, and that the three-dimensional structu res of objects can appear systematically distorted even when viewed un der full cue conditions.