Propagation strategies for stereo image matching based on the dynamic triangle constraint

For the purpose of reliable stereo image matching, this paper discusses a novel propagation strategy of image matching under the dynamic triangle constraint. Firstly, the construction and the dynamic updating method for the corresponding triangulations on the stereo pairs are introduced, which are used as both constraints and carriers during the matching propagation. Then, three propagation strategies: the stochastic propagation, the adjacent propagation based on the topological relationship of triangles, and the self-adaptive propagation, which considers the texture features are proposed. The detailed algorithms of these three propagation strategies are also presented. To compare these strategies, a stereo pair with typic texture features is employed to describe the different propagation manners of these three strategies, and an experimental analysis is illustrated with different aerial stereo pairs. From test results, the following has been found: (1) stochastic propagation gives the worst matching results; (2) self-adaptive propagation performs better than the adjacent propagation by making use of the global “best first” strategy. From these conclusions, the self-adaptive propagation strategy is recommended for reliable stereo image matching under the dynamic triangle constraint.