Research On Acquisition And Visualization Of Three Dimensional Data For Collection Of Cultural Relics

As the carrier of culture,cultural relics play an important role in the development of culture.However,with the influence of human activity and the passage of time,ancient artifacts have been continuing to suffer damage,so heritage protection and promotion work has become an important issue.The digitization of cultural relics is the most scientific method for the protection and promotion of cultural relics.It not only records the original three dimensional and texture information to acquisite the really three dimensional digital models,but also provides important data and model support for the restoration of cultural relics.The current three dimensional scanning technology,digital camera technology,and three dimensional rendering technology all have provided the feasible technical support for the digitization of cultural relics.In this thesis,the three-dimensional data acquisition and visualization of collections of cultural relics is studied,from the three dimensional scanning,data processing,modeling and rendering,to the three dimensional printing and three dimensional display of cultural relics.Focusing on the typical collections of cultural relics,the 3D scanner of Go!Scan based on structure light is used to acquisite the 3D information,including the three dimensional structure and texture information;as for the oil painting,a micro three dimensional information acquisition system is independently improved based on the line laser scanning technology and 3D precision control platform.The scanning precision on X-Y axis is less than 10 ?m,and the scanning precision on Z axis is 2 ?m.In the process of data processing,the three-dimensional color point cloud is obtained from the one to one binding of scanning RGB color and three dimensional points.A series of data processing algorithm are studied taking the three dimensional color point as the smallest unit: the Euclidean distance weighting factor used in the point cloud denoising algorithm of K mean clustering,has effectively improved the outlier misjudgment rate;the curvature and normal vector are considered in the point cloud resampling algorithm at the same time,which has taken the structure and details of point cloud into account;in the point cloud registration algorithm,the boundary detection method based on the point cloud gravity center distance can reduce the complexity and improve the accuracy of the feature point extracting process;a tetrahedral mesh generation algorithm based on Crust algorithm is proposed,which introduces region division and Delaunay tetrahedral mesh generation into the Crust algorithm,the new algorithm not only improves the efficiency,but also avoids surface adhesion phenomenon in mechanical non closed area;in the triangular mesh optimization algorithm,a boundary region growth method based on the wavefront method gradually fills holes from the boundary of hole to the inside of hole,which can realize the repairing holes close to the actual structure.Based on object oriented spatial feature database technology,a three dimensional relics rendering engine is developed,combining with the object oriented technology,service oriented architecture technology,three dimensional rendering technology,B+ tree index algorithm,levels of detail display technology,and Web services technology.This engine overcomes the problems of traditional technology that the data must be segmented according to spatial data types,the data organization is complex,and three dimensional data reconstruction and visualization effect is low.The engine has an excellent reconstruction ability of three dimensional scene with batch models and a realistic rendering effect of single model.After the establishment of three-dimensional color digital model of collections of cultural relics,on the one hand,the model can be used for three dimensional printing,the solution for the continuous printing before and after the pause operation in the three dimensional printing process was proposed;on the other hand,the digital museum platform based on cloud computing and mobile Internet technology is established,which changes the traditional display method that ordinary people must go to the museum,and realize the mobile roaming mode that audience can see the vivid and three dimensional museum through mobile terminal.