Research And Implementation Of 3D Fragment Stitching Algorithm Based On Point Cloud

In the long history of continuous change and development,many cultural relics have been damaged due to natural or human factors.With the continuous development and wide use of 3D laser scanner,cultural relics mosaic technology based on 3D point cloud data processing has become a very important research field.In this paper,the 3D fragments with obvious thickness feature are taken as the research object,and the 3D fragment stitching algorithm is studied and implemented.In this paper,we first preprocess the 3D point cloud model,remove the irrelevant point cloud and outliers,and then do voxel filtering for the preprocessed point cloud model.Secondly,the covariance matrix is used to extract the potential feature points of 3D model,and the potential feature points are clustered and refined to get the feature points.Then,the feature points are broken line growing to get the feature broken line,the feature broken line is repaired,and the cubic B-spline method is used to fit the repaired feature broken line to get the smooth feature line.Finally,the surface of 3D model is segmented and the fracture surface is identified according to the feature line.Aiming at the problem of correct matching between three-dimensional fragments,this paper proposes a method of stitching from coarse to fine.Firstly,the extracted features of the fracture surface are used to find the initial matching pairs,which are labeled as the source point cloud and the target point cloud respectively.Secondly,the feature descriptors of the points on the fracture surface of the source point cloud and the target point cloud are calculated respectively to perform the rough splicing between the fracture surfaces,and the rotation translation matrix between the fracture surfaces is calculated to complete the rough splicing between the fragments.According to the rough splicing,the initial position of the fragments is obtained,and the fine splicing between the fragments is carried out by using the least square method.Finally,the stitched 3D model is obtained.Aiming at the non thin-walled 3D model,this paper designs and develops a fragment splicing system based on 3D point cloud.The system has good cross platform performance and is easy to operate.It can quickly complete the splicing of multiple fragments.