Fig. 14.

Containment vs. Support. (A) Object boundaries along a container rim are highly detectable by the model from motion flow at motion discontinuities. (B) In contrast, object boundaries on the surface of a supporting object are not detectable from motion flow. These two types of boundaries arise from different types of surface discontinuity: contours of depth discontinuity at the container rim (occlusion contours), vs. contours of discontinuity in surface orientation, e.g. along the internal edges of a box. Arrows indicate the objects rotation. Color maps at bottom show the computed gradient of the optical flow: bright colors show high gradients along contours of motion discontinuity. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)