关键词: 立体匹配, 视差范围, 前向搜索, 迭代细分

Abstract: Setting up reasonable range of disparity search can improve the speed and precision in stereo matching. Therefore, this paper proposes an image recursively divided method based on the forward search that estimates the upper and lower limits of the disparity range. Firstly, the reference image is evently divided into a plurality of image blocks, then the current matching block is evently divided with the forward search strategy in the each process of block matching and its sub-blocks are matched with similarity principle. When calculating the upper disparity range, the disparity value of the current block is expressed as the maximum disparity value of the sub-blocks, after finding the maximum disparity image block, it is recursively divided until getting a stable upper limits of the disparity range. When calculating the lower disparity range, the disparity value of the current block is expressed as the minimum disparity value of the sub-blocks, after finding the minimum disparity image block, it is recursively divided until getting a stable lower limits of the disparity range. The experimental results show that the method of using forward search strategy to calculate the disparity range can achieve 28.8% reduction rate of search space while preserving 98% hit rate on average, compared to direct matching, the error rate is reduced by 47.4%, the disparity range is more accurate.

Key words: stereo matching, disparity range, forward searching, recursive subdivision