PERCEIVING MOTION AND RIGID STRUCTURE FROM OPTIC FLOW - A COMBINED WEAK-PERSPECTIVE AND POLAR-PERSPECTIVE APPROACH

Structure-from-motion algorithms based on weak-perspective projection have many interesting properties and could serve as a basis for a mode l of human perception of motion and structure from motion (M&SFM). The re is some psychophysical evidence, however, that points to discrepanc ies between what can be accomplished with these algorithms and the per formance of human subjects in certain M&SFM tasks. In light of this ev idence, this paper presents a mechanism that both takes advantage of a ll the possibilities offered by a weak-perspective approach and behave s in a manner that is in close correspondence with human performance i n M&SFM tasks. It consists of a novel weak-perspective-based method op erating at small visual angles and a complementary, perspective-projec tion-based method operating at larger visual angles.