A method and a system for progressive stereo matching of digital images
representing a scene. In general, the present invention uses a
progressive iterative technique that includes a disparity gradient limit
principle and a least commitment strategy. Generally unambiguous pixel
matches are found by beginning with a few reliable pixel matches and
finding progressively more unambiguous pixel matches. Unambiguous pixel
matches are used to define the search ranges for each pixel to guide
matching in the current iteration. Unambiguous pixel matches then are
found using a novel correlation technique and based on a correlation
score associated with a pixel match. The search range is capable of being
rotated, and is part of a novel correlation technique that provides a
more robust estimate of pixel match reliability. Potential pixel matches
found in the search ranges are tested for ambiguity and unambiguous
matches are selected and added to the reliable pixel matches.