SPATIAL CONSTANCY AND THE VISUAL-PERCEPTION OF SURFACE CURVATURE FROM OPTICAL-FLOW

Multiple views (successive or simultaneous) of the same object provide the visual system with depth information through motion or stereopsis. The retinal velocity field and binocular disparities are coded in the visual system, and may be used in an intermediate step of the visual processing of 3-D structure. Here we address the problem of recovering an intrinsic characteristic of surfaces - curvature - from moving images. We provide a theory about visual detection of surface curvatures and show how our model can be extended to stereopsis. Experimental validation of this model is brought about by our own experimental work as well as by that of others. We also discuss how spatial constancy can emerge from the visual processing of multiple views.