Disparity space image based stereo matching using optimal path searching

The current paper proposes a fast stereo matching algorithm based on a pixel-wise matching strategy that can produce a stable and accurate disparity map. Since the differences between a pair of stereo images are only small and such differences are just caused by horizontal shifts in a certain order, matching using a large window is not required within a given search range. Therefore, the current study adopts a disparity space image(DSI) for efficient pixel-wise matching. In a DSI, each disparity value is derived from the matching path. As such, when the matching path in a DSI innately satisfies the ordering constraint, continuous matching is possible. In addition, since this continuous matching also considers neighbor pixels, it assumes the characteristics of region-based matching, similar to window-based matching, yet with a lower computational load. To avoid the unstable characteristic of the pixel-based matching, we modified the directions in the cost array in the dynamic programming(DP). Experimental results demonstrate that the proposed method can remove almost all disparity noise and produce a good quality disparity map within a very short time.