| With the increasing availability of digital projection technology,there is a rapid development in three-dimensional measurement technology based on fringe projection.DFP has the advantages of non-contact,high-precision and high speed,thus it is widely used in numerous areas including virtual reality,cultural relic protection,medical health and industrial inspection.DFP can be divided into two techniques based on whether or not it require multiple projected patterns: single-shot and multi-shot techniques.To realize the three-dimensional measurement of the surface of dynamic objects,this thesis is based on the three-dimensional measurement of single-shot technique.The main work and research contents of the thesis are as follows:(1)The phase extraction method of wavelet transform profilometry based on singleshot technique is studied.To solve the influence of noise on the accuracy of phase extraction in real situations,the collected deformed fringe pattern is preprocessed.The adaptive median filter is used in denoising the noise,which improves the accuracy.(2)The branch-cut method in the spatial phase unwrapping method is selected for phase unwrapping.To solve the problem that the branch-cut length is easy to fall into the local optimum,Tabu search is applied to optimize the length of branch-cuts and further improve the speed and accuracy of phase unfolding.(3)The calibration of the camera and projector determines the accuracy of dynamic 3D reconstruction.The camera imaging model is introduced,and the formula for converting twodimensional coordinates to three-dimensional coordinates is derived;the principle and process of camera calibration and projector are described in detail,and corresponding experiments are carried out.(4)The experimental system is built and the experiment of dynamic 3D reconstruction based on single-shot technique is completed.The dynamic 3D reconstruction of human hand and face is realized,and the implementation details and results are given. |
PDF Full Text Request