A THEORETICAL-ANALYSIS OF ILLUSORY CONTOUR FORMATION IN STEREOPSIS

A theoretical analysis of how illusory contours are formed in untextured stereograms is presented that focuses on the role of contour junctions in initiating surface interpolation processes. This theory asserts that the matching geometry of stereoscopic junctions-that is, the pattern of matchable and unmatchable features present at the intersection of binocularly viewed contours-initiates processes of illusory contour formation ( modal completion) and the connection of partially occluded objects (amodal completion). The matching geometry of 3 forms of stereoscopic junctions that elicit percepts of illusory surfaces is derived under the assumption that only horizontal disparities are matched. This analysis reveals the presence of 2 distinct kinds of monocular features generated by binocular viewing. Experiments and demonstrations are presented that reveal the role these monocular features play in modal and amodal completion in stereopsis.