DETECTION OF ONE VERSUS 2 OBJECTS IN STRUCTURE-FROM-MOTION

The ability of subjects to detect whether a structure-from-motion disp lay depicts one or two rigid objects was examined in the presence or t he absence of noise points. Each object was composed of a set of point s chosen randomly within the volume of a sphere. The objects rotated r igidly about different axes passing through the center of the sphere. For displays without noise points, detection increased with larger ang les between the rotation axes and with more points in each object, For displays in which noise points were present, detection was above chan ce but, in general, worse than that for displays without noise points. The implications of these results for image segmentation in complex m otion patterns is discussed.