Stereo matching using cost volume watershed and region merging

Segment based disparity estimation methods have been proposed in many different ways. Most of these studies are built upon the hypothesis that no large disparity jump exists within a segment. When this hypothesis does not hold, it is difficult for these methods to estimate disparities correctly. Therefore, these methods work well only when the images are initially over segmented but do not work well for under segmented cases. To solve this problem, we present a new segment based stereo matching method which consists of two algorithms: a cost volume watershed algorithm (CVW) and a region merging (RM) algorithm. For incorrectly under segmented regions where pixels on different objects are grouped into one segment, the CVW algorithm regroups the pixels on different objects into different segments and provides disparity estimation to the pixels in different segments accordingly. For unreliable and occluded regions, we merge them into neighboring reliable segments for robust disparity estimation. The comparison between our method and the current state-of-the-art methods shows that our method is very competitive and is robust particularly when the images are initially under segmented.