Research On The Technology Of Point Cloud Skeleton Extraction And Matching Of Terra-cotta Warrior’s Model

Curve skeleton is one-dimensional representation of a three-dimensional model, with rich topology information, and has become top research in computer graphics, virtual reality, scientific visualization and other disciplines. It is widely used in education model library retrieval, virtual navigation, medical visualization, computer animation, interactive game development and other areas. As the technology of point cloud data acquisition is becoming more and more convenient and popular, our group in the digital protection of Terra Cotta Warriors issue(the third excavation of pit One and excavation of pit K9901 of Qin Shi Huang Mausoleum) have established 82 point cloud models. In this paper, we take these models as research-objects, and deeply research on the technology of their skeleton extraction and matching, the results can be used in shape analysis, identification and retrieval and other neighborhood rigid of cultural model such as Terra-cotta Warrior, the main work includes:(1) Proposed a point cloud skeleton extraction algorithm based on the norm of L1. The L1-median defines the global center of an arbitrary set of points and has low sensitivity to the input data. This paper applies L,-median locally to a point set representing a 3D shape and gives rise to a one-dimensional structure that always in the center of the local space, and identifies it as the localized center of the shape. Our approach does not place strong requirements on the geometry or topology of the shape nor the quality of the input point cloud. It can extract better curve skeleton for point cloud model with noises or large missing data, and reserves the topology features of the original point cloud.(2) Proposed a matching algorithm based on skeleton diagram. The approach is to compare the geodesic path distance between the end points and junction points to match the key points of skeleton diagram. The junction point can carry the global structure information of model and the path between the junction point and the end point can represent the specific local geometry of model. Experiments show that our skeleton graph matching method can get the correct local correspondence and achieve the desired accuracy.(3) Designed and developed a point cloud skeleton extraction prototype system. The system is interactive, easy to operate. It can quickly and accurately extract the curve skeleton of the Terra Cotta Warriors point cloud model, we can use the extracted skeleton features to identify and match the model of Terra-cotta Warrior.