Abstract: Different from the traditional region growing matching algorithm which is excessively dependent on the growing threshold,PRPGM(Progressive Reliable Points Growing Matching) sets a sequence of thresholds from high to low for both seed point selection and growing matching to implement the stereo matching in an iterative process,thus enhancing the results’ robustness on the thresholds．A research has employed this method for depth estimation for speckle projection system and achieved good results．However,it motivates us to conduct this research that the calculation is not fast enough for practical applications as well as there are still many illegal points on the disparity map．We proposed a sparse seed point selecting method that selects seed point from grid divided by certain size on the speckle pattern image in the stage of selecting seed point and a jumping growing matching method instead of the conventional connectivity constraint of 4-neighbors domain during the growth of the reliable points．Both of the above revises have been verified to improve calculation speed greatly．Meanwhile,we applied the PRPGM to handle illegal points in post-processing of stereo matching and eliminated most of illegal points consequently.

Key words: Stereo matching,Speckle pattern image,Region growing,Invalid point