An efficient approach for stereo matching of planar objects in stereo-digital image correlation

摘要

In many standard mechanical tests and in all two-dimensional digital image correlation (2D-DIC) applications, the surfaces of specimens to be measured are planar. For the special case of planar surfaces, in this paper an efficient approach for stereo matching was proposed to further improve the computation efficiency of stereo-DIC. The proposed stereo matching method utilizes the characteristic of planar objects that the projection transformation functions between left and right images are the same for all matched subsets and can be expressed by eight parameters. In each pair of images, four discrete points were matched to calculate the projection transformation matrix, and then the stereo matching of all other points could be accomplished based on the calculated projection transformation matrix in an easy and efficient way. Both simulations and experimental results demonstrated that the proposed method is feasible and effective and the computational speed is about 20 times faster than that of traditional method. Based on the proposed method, real-time stereo-DIC with a higher frame rate and more points should be achieved.