Study On Surface Reconstruction Of 3D Laser Scan Data

With the rapid development of the software and the hardware which have a close relationship with 3D imaging, 3D digitizing technology is paid more attention widely. Generally, there are three main parts in 3D digitization technology: sampling, surface-mesh reconstruction and surface information obtaining. Surface-mesh reconstruction is the process of constructing object-mesh with correctly topological structure on vast 3D point cloud data. It is the bridge to connect point cloud data and object surface. The quality of the reconstruction plays an indispensable role in the subsequent progresses, such as object recognition, character extraction and 3D measurement. On the other hand, 3D surface is only reconstructed on point cloud date, the topological structure of the object isn't known beforehand, much knowledge in many areas are used such as computational geometry, topology and computer graphics. Thus the research of reconstruction algorithm on 3D surface is essential in theory and practice.The article researches on point cloud date sampled by the laser 3D scanner, which was designed by our laboratory. There are four parts as follows.1. Pretreatment on point cloud data. Two algorithms are used: the algorithm to delete noises by the method of maximum connected domain and the algorithm to simplify point cloud data by estimating degree between lines of adjacent points. And results of these algorithms are analyzed.2. 3D surface reconstruction. This is the main part of the article. An improved algorithm is applied which based on the marching cubes mesh reconstruction algorithm. By the aid of local-tangent-planes-based method, the tangent plane is estimated, the normal vector is adjusted and the directional distance function is calculated. Both the speed and the effect of the reconstruction are improved.3. Optimizing of 3D meshes. After mesh simplification, the 3D meshes are optimized by local optimization arithmetic. Results show that the meshes are reduced and the speed of display is improved. Meanwhile, the quality of mesh-displaying is not deteriorated any more.