Hue feature-based stereo scheme for detecting half-occlusion' and order reversal of objects

摘要

One of the most challenging tasks in stereopsis is to find corresponding points in a stereo image pair to obtain depth information. Half occlusion and order-reversal of objects further complicate the problem. In this paper, we propose the use of hue and intensity of images for stereo correspondences. Stereo correspondence is performed row by row. Planar first-order least squares curve-fitting is exploited to extract line-segments with similar hue. A sloping intensity profile of line-segment is used to indicate the presence of a sloping surface with the same hue. A Left-Left Right-Right (LL-RR) constraint is introduced for matching line-segment pair: the possible occluded part should be located both at the leftmost part of the left-line-segment and at the rightmost part of the right-line-segment. This constraint is used to detect half-occlusion in line-segment pair matching. Finally, an object is formed from a block of contiguous line-segments separated from other blocks by gaps. Experiments were performed on stereo image pairs and the estimated disparity maps are used to evaluate the performance of the proposed algorithm.