A maximum-flow formulation of the N-camera stereo correspondence problem

This paper describes a new algorithm for solving the N-camera stereo correspondence problem by transforming it into a maximum-flow problem. Once solved, the minimum-cut associated to the maximum-flow yields a disparity surface for the whole image at once. This global approach to stereo analysis provides a more accurate and coherent depth map than the traditional line-by-line stereo. Moreover, the optimality of the depth surface is guaranteed and can be shown to be a generalization of the dynamic programming approach that is widely used in standard stereo. Results show improved depth estimation as well as better handling of depth discontinuities. While the worst case running time is O(n/sup 2/d/sup 2/log(nd)), the observed average running time is O(n/sup 1.2/ d/sup 1.3/) for an image size of n pixels and depth resolution d.