Figure 3.

Illustration of (a) object mask extension [40,45] and (b) object mask pruning [57]. Both employ attentional mechanisms, focusing on one object at a time. Object mask extension takes as input a subset of the true object and adds missing parts, whereas object mask pruning takes as input a superset of the true object and subtracts excessive parts. Both tasks typically use the raw image (or some alternative representation) as an extra input to figure out the right answer, though object mask pruning may be less dependent on the raw image [57].