国产欧美精品一区二区,中文字幕专区在线亚洲,国产精品美女网站在线观看,艾秋果冻传媒2021精品,在线免费一区二区,久久久久久青草大香综合精品,日韩美aaa特级毛片,欧美成人精品午夜免费影视

Towards to the problem of vision measurement on the large profile measurement of rail transit tunnel, research and design of a large and multi-array circular calibration plate for system calibration work. The method of region growing barycenter is proposed to extract the datum points on the calibration image. Combining the region growing method and the gray barycenter method, the seed point of each datum circle are searched by rough location and while 4 neighborhood pixels of the seed points’ pixel are considered for region growth. Then the gray barycenter method is used to extract the barycenter of the growing area as the datum point. In order to eliminate the effect of the image distortion, the nonlinear change datum points is substituted for the seed points of the linear datum circle. This method not only ensures the reliability and robustness of the feature detection process, but also can be used for the extraction of the datum points of the large and multi-array circular calibration plate. The profile of reduction experiment was carried out by carry a fisheye lens to shoot the simulation of tunnel cross section with 6 m. The experimental results show that the pixel coordinate error of the datum points extracted by this method can reach within 2pixel. The system precision can reach within ±5mm and fully meet the errorSstandard for the cross section measurement of rail transit tunnel.