Abstract

Perceived depth of rotating ellipsoids and elliptical cylinders was examined with depths specified by motion, texture, and stereo independently manipulated. The combined depth estimate was a linear function of each cue. By manipulating the reliability of individual cues we found that the weight assigned to a cue depends upon its quality. Using only texture and motion, we found that when cue reliability was reduced, the weights summed to less than one and perceived depth decreased. To offset the extraneous cues from the flat display that may account for the remainder of the weight and reduce perceived depth, we improved the display by adding a stereo cue. In displays with sufficient high quality depth information, pilot experiments indicate that the weight subtracted from a reduced quality cue is redistributed among the remaining depth cues rather than being assigned to flatness. Extraneous cues may also play a role in Loomis and Eby’s (ICCV, 1988) finding that the perceived depth of ellipsoids specified by motion alone decreased as the angle between the line of sight and the rotation axis decreased. Using stereoscopic movies of textured ellipsoids, we find that the overall depth percept does not diminish for rotations about axes nonorthogonal to the line of sight until we approach the degenerate case (rotation about the line of sight). Thus, when there are rich depth cues, perceived depth does not decrease as a result of reducing the reliability of one of the depth cues.

© 1992 Optical Society of America