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.
The progressive iterative technique finds generally unambiguous pixel matches by
beginning with a few reliable pixel matches and finding progressively more unambiguous
pixel matches. Unambiguous pixel matches found in the previous iteration are used
to define the search ranges for each pixel to guide matching in the current iteration.
Unambiguous pixel matches in the current iteration 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 of the present invention that provides a more robust estimate of pixel
match reliability. Potential pixel matches found in the search ranges are tested
for ambiguity and any unambiguous matches are selected and added to the set of
reliable pixel matches. The ambiguity testing includes determining a correlation
score for the pixel match and classifying the match based on the correlation score.
The present invention also includes a system for progressive image matching that
incorporates the method of the present invention.