Binocular Structured Light Three-dimensional Reconstruction Based On Multi-frequency Heterodyne Method

With the arrival of a new wave of industrial revolution,the development of the manufacturing industry urgently needs more efficient and accurate three-dimensional measurement technology.The advantages of computer vision three-dimensional reconstruction technology have become increasingly prominent.Structured light and binocular stereo vision three-dimensional reconstruction technology are important branches of computer vision,and their applications in industrial measurement are more and more extensive.However,the reconstruction accuracy of the structured light is limited by the manufacturing accuracy and calibration accuracy of the projector.And the errors in the reconstruction of objects with weak textures and repeated textures in the binocular stereo vision are relatively large.Therefore,improving the three-dimensional reconstruction accuracy of structured light and stereo vision has important research significance and application value.In this paper,based on the study of monocular structured light,the binocular stereoscopic stereo matching algorithm is combined,and the absolute phase value is used as the matching object,a three-dimensional reconstruction method of binocular structured light based on the multi-frequency heterodyne method is constructed.In this paper,the binocular stereo vision is first studied.Camera model and camera parameters calibration are the basis of three-dimensional reconstruction of computer vision.This paper combs the mapping relationship between the three-dimensional space points and the two-dimensional image plane,and discusses the camera nonlinear calibration method.According to the principle of stereo vision,the reconstruction process and algorithm of binocular structured light with large optical axis angle difference are deduced.Monocular structured light three-dimensional reconstruction technology is widely used in industrial measurement,and its methods are various.This paper studies the monocular structured light based on multi-frequency heterodyne method for high-precision measurement,and deduces the multi-frequency heterodyne solution phase principle and depth calculation method.This paper focuses on the study of monocular structured light optimization methods,and optimizes the projector's inverse camera calibration method and system Gamma distortion.In this paper,we study the problem of brightness saturation caused by the high reflectance of the surface of the measured object,and propose a partitioned projection optimization compensation method to improve the reconstruction accuracy of the monocular structured light.However,the optimization algorithms of projector calibration,optical defects and the system Gamma distortion still have some limitations,and through the binocular structured light can completely avoid these defects.In this paper,we study the absolute phase distribution characteristics obtained by multi-frequency heterodyne dephasing and based on two matching algorithms,the SAD and AD-Census,in binocular stereo matching,achieve the disparity calculation by matching absolute phase values.In addition,the disparity refinement calculation method is studied to optimize the accuracy of sub-pixel disparity and improve the accuracy of binocular structured light reconstruction.Finally,an experimental platform was set up,and the three-dimensional reconstruction accuracy of the monocular and binocular structured light was compared and analyzed.The effectiveness of the binocular structured light reconstruction method described in this paper for improving the reconstruction accuracy is proved.