Research On 3D Reconstruction Of Antique Based On 3D Laser Scanning And Digital Photogrammetry

The three dimensional modeling is an important method and means of protection of cultural relics.There have a lot of methods to be used for 3D model,but the more research and application methods is 3D laser scanning technology and photogrammetry technology.3D laser scanning technology can quickly obtain exact three-dimensional coordinates of the model surface,but it also has some shortcomings.First,the color information can't satisfy the requirement of realistic model building.Second,scanning the three-dimensional point cloud data often exists cavitation.Photogrammetry method can well make up for the inadequacy.Because of the image to obtain is simple and arbitrary,so it can according need to obtain specific parts of the image.At the same time the image date contains more abundant texture information.How to combine the two methods is a problem need to study,enable it to have complementary advantages,to build a more detailed 3D model.First of all,collect date of the target and build model by respective using 3D laser scanning technology and photogrammetry technology.Then we have two sets of model data.Based on the laser point cloud model,transform the two groups of model to the same coordinates by using the method of point cloud registration between different scales.And then find the empty position in the laser point cloud data,by using the photogrammetric model points repair the hole in laser point cloud to perfect the point cloud model.According to the photogrammetry camera position and scene geometry method,get the mapping relationship between image and model.We can realize texture mapping for the model to get the realistic 3D model.In laser point cloud model building,the registration multistation data is the key to build the model.I use the normal vector characteristics of the point cloud and the improvement of ICP algorithm to realize automatic registration between different viewpoints of point cloud.In the process of building 3D model of photogrammetry,i take the SFM algorithm to generate target 3D point set and image exterior orientation elements by using the image data.For registration between the two model,seven parameter and beam adjustment method is used to solve the transformation matrix between the two models through selection of more than three control points.Basis of theoretical analysis,use the measured data to verify this method.Point cloud registration error is 0.3 mm,meet to the need of antiquities three-dimensional model building.Point cloud loopholes is fixed.The texture map of model is vivid,increase the sense of reality model.This indicates that the 3D laser scanning technology and photogrammetry method combination are applied to constructing 3D model is feasible and practical.