Abstract
Images of artificial and natural scenes typically contain many highlights generated by mirror-like reflection from glossy surfaces. Until recently, computational
models of visual processes have tended to regard highlights as obscuring the structure of the underlying scene. The truth is that, on the contrary, highlights are
rich in local geometric information. Here we report that the three-dimensional appearance of a highlight on a computer-simulated stereoscopic curved surface
affects observers‘ judgement of surface gloss. We also show that the 3-D appearance of a highlight affects the perception of surface curvature -- that is, it can
force an ambiguous convex-concave figure to change state. We thus conclude that human visual analysis seems to employ a physical model of the interaction of
light with curved surfaces, a model firmly based on ray optics and differential geometry.
