基于最小角度三角化填充的枝干点云根部空洞修补  

Filling Tree Root Hole in Branch Point Cloud With Triangulations Based on Minimum Angles

作　　者：杨杰[1,2] 温小荣 汪求来[3] 叶金盛 YANG Jie;WEN Xiao-rong;WANG Qiu-lai;YE Jin-sheng(Co-Innovation Center for Sustainable Forestry in Southern China,Nanjing Forestry University,Nanjing 210037,Jiangsu,China;Faculty of Forestry,Nanjing Forestry University,Nanjing 210037,Jiangsu,China;Guangdong Forestry Survey and Planning Institute,Guangzhou 510520,Guangdong,China)

机构地区：[1]南京林业大学南方现代林业协同创新中心,江苏南京210037 [2]南京林业大学林学院,江苏南京210037 [3]广东省林业调查规划院,广东广州510520

出　　处：《西北林学院学报》2023年第4期214-223,共10页Journal of Northwest Forestry University

基　　金：广东省林业科技创新项目(2021KJCX001);国家重点研发计划(2016YFC0502704);江苏高校优势学科建设工程项目(PAPD)。

摘　　要：激光雷达扫描仪获得的树木点云仅表达了树木的表面,缺少根部截面的点云,因而往往是不封闭的,这一特性对树木建模的2种主要方法(骨架和Delaunay三角网)都会产生影响,增加了额外处理工作并且降低了模型精度,而现有研究中点云的空洞修补方法并不能直接应用于枝干点云根部。针对这一现状,结合对现有空洞修补方法进行改进,并适用于枝干点云的根部,分为由预处理、根部空洞边界的获取、基于最小角度法的空洞三角化填充与后处理4个阶段,并以C++编程实现,以根部空洞修复和未修复的骨架对比了效果。结果表明,r_(be)、α、k、ε4个参数设置合理时填充枝干点云能够在正确监测点云空洞边界的基础上较好且快速地修复根部的空洞,使用处理后的点云建立的骨架相较于未处理的中心偏移明显改善,因而有助于提高枝干建模的精度。该方法拓宽了点云空洞修补的适用场合。Only the surface of a tree can be expressed in the point cloud provided by a LiDAR scanner.Tree point clouds are always unclosed for lack of the section of the root.The feature has a bad influence on two major methods of tree modeling,including skeleton and Delaunay triangulation,which increase extra processing work and decrease the accuracy of models.However,the existing methods of point cloud hole-filling cannot directly apply to the root section in tree branch point cloud.Aimed at this issue,the method proposed in the research improved the existing hole-filling methods to satisfy the applicability of handling the root section in tree branch point cloud.It was divided into four stages:preprocessing,obtaining the root cavity boundary,cavity triangulation filling based on the minimum angle method and post-processing.It was implemented by C++programming for showing the difference between the skeleton produced after hole-filling and without hole-filling.The results showed that when four parameters were set rationally r _(be),α,k,εfilling the root hole of the branch point clouds was better and quick.Compared with the branch point cloud before root hole-filling,the produced skeleton with that after root hole-filling had smaller center deviation.Therefore the research is helpful to improve the accuracy of tree branch modeling.Additionally the method can broaden applicable occasion of point cloud hole-filling.

关 键 词：空洞修补 DELAUNAY三角网 树木建模 

分 类 号：S758[农业科学—森林经理学]