Abstract:

Abstract: For traditional extraction methods of hole boundary were affected by noise and single-valued surface, this paper proposed an automatic extraction method for the multi-valued surface repair to overcome the problem of overlapping projection. First, the k-nearest neighbors calculated from the scattered point clouds were projected to the plane by the method of ALS; then the mesh was divided within the plane to extract the boundary grid and propose boundary line using the minimum convex hull; finally, the hole boundary and the object boundary was identified. In order to verify validity, the method is applied to fill up the hole and surface reconstruction which is used to analyze and evaluate the accuracy using the quantitative evaluation index of the maximum distance and the average distance from the sample points to the built surface model. The results show that ALS and the minimum convex hull can keep characteristics and avoid the problem of overlapping projection. The extracted hole boundaries are very precise to meet the needs of follow-up modeling.