Design Of Binocular Vision 3d Reconstruction System Based On Digital Speckle

In recent years,with the development of industrial technology and the demand of the daily life,how to get object 3D information has become a hot research topic which people concern,3D reconstruction,as a kind of convenient,quick and accurate to obtain 3D information technology method,is widely used in machine vision,automatic obstacle avoidance,reverse engineering and many other aspects.3D reconstruction technology is mainly through the camera to obtain images from different point of the object under test for stereo matching with corresponding points.The commonly used 3D reconstruction technique of stripe structured light requires encoding multiple images projected onto the measured object,which limits its application range.Therefore,a 3D reconstruction system which is based on digital speckle is studied in this paper.This system improves the matching effect of weak texture and untextured region by projecting speckle images on the measured object,so as to realize the single reconstruction of the object.The system is widely applicable and can quickly obtain the 3d information of the object.In this paper,the 3d reconstruction model of binocular vision which is based on parallel camera axis is firstly studied.Then the imaging model of camera and the method which are used in calibrating camera have been simply intruduced,according to the world coordinate system to the mapping relationship between image coordinate system,by zhang calibration method to calculate the information which is about internal and external parameters of binocular cameras,the system calculates the Euclidean distance between the corners of the checkerboard grid by calculating the three-dimensional coordinates of each corner of the checkerboard grid,verifies the calibration results by measuring the measured distance and the actual distance between the corners of the checkerboard grid,and obtains the calibration results of the average error is 0.0075 mm.According to the gaussian distribution law of speckle,the generation algorithm of digital simulated speckle is studied.The gray binarization and gray random two global speckle pattern has been simulated,through the proposed binarization gray speckle generated area is divided into local speckle pattern,through the gray-level histogram and average gray level gradient emphatically analyze three kinds of speckle pattern,by adjusting the spot diameter of speckle and SAD cost window size,design controled experiment to compare three kinds of speckle images,and the speckle images with better auxiliary effect are selected as the structural light of the system.The system realizes a convenient and visual interactive interface through the MFC framework,collects the image of the object under test after digital speckle modulation,and realizes the stereo matching of the left and right eye images by using SGBM algorithm.The system carries out reconstruction experiments on the gypsum cylinder and the ceramic tank,and obtains the point cloud data of the cylinder and the ceramic tank.By fitting the cylinder with the point cloud data,the system's reconstruction accuracy is verified by the comparison between the measured data of the fitting cylinder and the real data of the cylinder as well as the standard deviation of the point cloud data of the cylinder.