Research On Three - Dimensional Calibration Method Of Digital Stereo Microscope

With the development of science and technology,as well as the demand of the society, the research on the shape, size, and internal structure of the micro object and its position modification has become a hot topic. The digital micro stereo vision system has the advantages of simple, convenient, good real-time,etc. Since the emergence of visual feedback mechanism, digital micro stereo vision system has been used for the 3D location of the tiny objects, the 3D shape reconstruction and measurement. Because of the function of information feedback in the system, thus it can be applied to practical production, such as micro assembly, micro operations and biological engineering, etc. Calibration whose accuracy directly determines the precision of the position of tiny objects is very important in the technology of digital micro stereo vision. In order to get the 3D shape and location information of tiny object more accurate, the calibration of micro stereo is needed. This paper studies on the methods of stereo calibration in terms of digital Stereo microscope, the concrete research content is as follows:(1) Analyze the linear camera model and the nonlinear distortion correction model in depth, and further to understanding the four step calibration algorithm, then combining it with the calibration characteristics of digital stereo microscope, this paper puts forward a stereo calibration method of the digital stereo microscope.(2) Set up the calibration platform of digital stereo microscope, and calibrate the digital Stereo microscope on the platform, thus get the internal and external parameters of the digital stereo microscope. According to the internal and external parameters which have calibrated, the recovery image is obtained.By comparing the recovery image and the original image, four-groups correction factors and correction external parameters are achieved.(3) According to the experimental correction external parameters, the method of 2D measuring quantitative is applied to evaluate. By analyzing distance distribution map of corresponding points of the restored image andoriginal image,optimum correction factors and correction external parameters are selected. On the basis of the internal and external parameters, the 3D measurement method is adopted to evaluate its accuracy, and apply the parameters to the three-dimensional reconstruction of 0603 resistance, then get the point cloud of 0603 resistance.