Study On 3D Reconstruction Of Structured Light Based On Photoelastic Fringes

Computer vision technology has been widely used in many fields in recent years,among which the three-dimensional reconstruction technology of structured light attracted a large number of researchers because of its accurate and lossless characteristics.Generally speaking,the three-dimensional reconstruction technology based on structured light obtains the three-dimensional information of the object by interpreting the distortion of grid lines and stripes.It integrates the technical means of optics,image processing,computer vision and other fields,and can quickly realize the three-dimensional reconstruction of the object,which has a wide application prospect.According to the photoelastic technology and the three-dimensional measurement method of structured light,this thesis designed a three-dimensional reconstruction method of structured light based on photoelastic fringes.The main research contents and the completed work are summarized as follows:(1)The types and measurement principles of structured light system were introduced and the physical model and coordinate system transformation in structured light system were described.The principle of camera calibration was expounded and the work of camera calibration was completed.(2)The work of introducing the basic concept and theory of photoelastic technology had been completed.The formula of light intensity of phase-shifting method in circularly polarized light field by Jones matrix was deduced.The simulation and experiment of photoelastic fringes in the circularly polarized light field of the radially compressed disk model were carried out(3)The three-dimensional reconstruction workflow based on photoelastic fringes generated by computer was designed.The methods of obtaining wrapping phase and unwrapping phase were studied and discussed.Then an experimental platform was built to test the proposed method,and the three-dimensional reconstruction based on digital photoelastic fringes was realized.(4)The physical model of three-dimensional reconstruction system usingphotoelastic instrument as projection device was constructed and the selection of photoelastic materials was studied and discussed.The design of three-dimensional reconstruction workflow and the construction of experimental platform were completed and the performance of the system was tested by using step model and semicylindrical model,and the validity of structured light system and the feasibility of the method proposed in this paper were verified.