Fig. 6.

Figure-ground segmentation. Analysis steps for a simple, non-container object (top) and a container (bottom). (A) Two consecutive frames from a familiarization video sequence. (B) Computed optical flow between the two frames using (Sun et al., 2013). Direction and magnitude are represented by hue and saturation respectively. The container both translates down and wiggles (see arrows). (C) Motion discontinuities are computed from local gradients of the optical flow. (D) Figure-ground segmentation for the two types of objects: (top) a simple object is separated from the background by an external boundary; (bottom) a container has in addition two sub-regions separated by an internal boundary at the container’s rim. Later, the hand is separated from the object using an additional image of the object at rest without the hand holding it.