Based On The Stereoscopic Measurement Gray Code And Phase Shift Combination

Along with the rapid development of the digital projection technology and computer vision theory, the binocular stereo vision measuring based on the digital projection has become one of the important 3d vision measuring in reverse engineering, has wide application, especially in length than the measurement of large components 1-m.The binocular stereo vision measuring based on compiling gray code with phase-shift is a new measurement method, which will project gray code raster and phase-shift raster onto the object by using digital projectors. Gray code value and phase value can be obtained through gray code and phase decoding. Stereo match based on gray code value and phase value is adopted and the disparity which is used to calculate three-dimensional coordinates is acquired. The process of 3d acquisition can be divided into the camera calibration, stereo matching and 3d reconstruction. This paper will study from these three aspects.Firstly, study the stereo camera calibration and stereo calibration principle, the development of stereo camera calibration module, and verify the feasibility of the module. Secondly, focus on the stereo matching. The key factors which affect the measurement accuracy of the binocular stereo vision measuring based on compiling gray code with phase-shift were studied. First, by comparing to determine the phase shift grating generated, and use a new way to reduce noise. Second, by contrast, a new period correction method-----the maximum probability correction method is proposed that this method can obtain better correction results. Third, dynamic programming, greedy algorithms are introduced to the stereo matching to obtain a better matching results, but the match takes a long time. A new matching algorithm - two-step matching method was proposed through the analysis, the use of this matching method, matching not only effective, but also short match time-consuming, and high efficiency. Finally, study the three-dimensional reconstruction. Not only developing three-dimensional reconstruction module completed the reconstruction of three-dimensional point cloud model, but also evaluating the accuracy of the measurement system. Measurement system is used in the specific instance of measurement and the measurement results obtained are similar with the three coordinate measuring machine (CMM). It is shows that the accuracy of the measurement system.