1. A method, comprising, receiving input data in a display of a set of multiple digital images comprising a stereo image pair, wherein the input data indicates a location within a region of a digital image of the stereo image pair; and defining a boundary of the region and a corresponding boundary of a corresponding region of another digital image, wherein the boundary and the corresponding boundary represent boundaries of a shared visual feature in the digital image and the another digital image, the defining is based on the input data, content of the digital image, and content of the another digital image, and the defining further comprises constructing a probability distribution for the digital image, wherein the probability distribution represents a probability that each pixel of a set of pixels of the digital image is within the region, and another probability distribution for the another digital image, wherein the another probability distribution represents a probability that each pixel of another set of pixels of the another digital image is within the corresponding region, and the probability distribution and the another probability distribution are based on correspondence probabilities between each pixel of the set of pixels and respective ones of the another set of pixels.