Research On 3D Reconstruction Technology Of Multi-frequency Phase-shift Structured Light

Fringe coded structured light three-dimensional reconstruction technology is an important method to achieve high-precision measurement of objects.However,the existing structured light coded fringes show obvious shortcomings in dealing with the complex texture of the object surface and the interference of environmental light,which directly affects the accuracy of subsequent decoding work.For this reason,this paper improves and optimizes the traditional sinusoidal fringe coding and decoding algorithm,and studies the causes of system distortion.The aim is to achieve high precision 3D reconstruction of the free-form surface of the measured object and obtain accurate 3D reconstruction model of the surface.Based on 2D plane target calibration method,the structured light system is calibrated by projector calibration method of projective relation.Based on the decoding algorithm of multi-frequency heterodyne method,an adaptive local mean filter is used to filter the intermediate phase to eliminate the phase errors caused by the periodic jump of heterodyne method.In this paper,the cause of phase error in structured light system is analyzed by sinusoidal phase shift method.The optimization of camera output response curve and the compensation of Gamma distortion of projector are carried out to solve the problem that the distortion may generate water ripple on reconstructing the surface of the object to be measured.In the stage of 3D point cloud computing,based on the triangulation principle of structured light system,the error point cloud caused by inaccurate edge coding information is filtered,and then the point cloud segmentation algorithm is used to extract the target point cloud completely,and the accurate 3D model of the object free surface is obtained.The experimental results show that the optimization and improvement of the traditional structured light system is effective,the stability of the structured light system is improved,and the more accurate 3D reconstruction results are obtained,which can promote the follow-up research of high-precision 3D reconstruction of structured light.