Research On Redundancy Elimination For Overlapping Point Clouds And Texture Mapping In A Grating Projection Rotation Measurement

With the development of computer science and technology,optical imaging technology and related hardware technology.As well as the continuous research and innovation of scholars at home and abroad.The grating projection topography measurement technology has made rapid development.At the same time,people's requirements for the quality of information are increasing,and the traditional way of information acquisition has gradually hard to meet the requirements of people at this stage.From the initial plane image to a high-precision 3D stereo model.With the continuous integration and development of computer technology and optical technology,the use of optical 3D topography measurement technology has become a mainstream trend in the field of 3D topography measurement.In order to improve the accuracy and efficiency of the model reconstruction in the grating projection topography measurement system,and improve the realistic visual effect of the overall model.This paper based on a grating projection rotation measurement system.Aiming at the problem of large point cloud data redundancy caused by point clouds splicing,and the lack of texture information in the reconstructed 3D model.Which is the redundancy elimination for overlapping point clouds between adjacent stations and texture mapping.The main contents are as follows:This paper first introduces a special measurement system,a grating projection rotation measurement system.The hardware and measurement strategy of this system are introduced respectively.And the key contents of the system,such as fringe grating coding,phase expansion,phase feature matching,phase space mapping,system calibration and depth recovery are described in detail.Next,aiming at the important technology of point clouds splicing in the omnidirectional measurement system.On the basis of summing up the splicing methods and principles commonly used at present.The principle of omnidirectional point cloud splicing in grating projection rotation measurement system,which using two constraints of acquisition space invariance and projection space invariance is mainly introduced.And the corresponding experiments are carried out.In the next step,aiming at the problem of a large number of redundant points in the point clouds splicing results of the measurement system.An algorithm of redundancy elimination for overlapping point clouds based on two-dimensional corresponding point pair constraints is proposed.In this algorithm,by combining the two constraints of the invariable projection space and the invariable acquisition space in the rotation measurement system.The fast location of the overlapped point pair between adjacent stations is realized,and the low accuracy of the overlapped point pair is removed by combining the comparison of the back projection residual value.Through the comparison of experimental data,the proposed algorithm can faster locate overlapping 3D point pairs between adjacent stations,with higher elimination rate,and the accuracy of the overall point cloud is higher after the redundancy elimination.Finally,in order to obtain a more realistic display effect.Texture mapping is carried out for the 3D model based on point representation.With the measurement strategy of rotation measurement system,this paper obtains the mapping relationship between 3D model space and 2D texture space by two-step mapping correspondence method.Taking the standard deviation and image information entropy of texture image in the same object area as the image quality evaluation index,and combines the global color transmission algorithm which can eliminate the texture seam problem caused by the texture image collected in different stations.The experimental results show that the method is effective.