Recognition of 3D Objects in 3D Scenes

Myron L. Braunstein


Abstract

J. J. Gibson proposed that we use the positions at which objects contact the ground in a 2D projection--optical contact--to perceive the layout of objects in 3D scenes. We considered this proposal in four series of experiments that used either computer-generated scenes, movies of real scenes into which computer-generated objects were inserted, or real scenes viewed directly. One series of experiments compared the effectiveness of optical contact with the ground to that of optical contact with other surfaces in determining layout. The other three series of experiments examined interactions of optical contact with motion parallax, occlusion and shadow. Optical contact with the ground was an effective source of information for layout, dominating optical contact with other surfaces. Optical contact was more effective than motion parallax for scenes with one or two objects, but not for scenes with three rigidly moving objects. A shadow on the ground was more effective than a second object on the ground in determining the perceived location of a floating object. These results support Gibson's emphasis on the importance of the ground surface in the perception of the visual world.


Maintained by Philippos Mordohai