快速生成等值线的凹包算法  

The fast contour generation algorithm use concave hull

作　　者：蒲朝旭[1,2] 杨武年[1] 林志鹏 PU Chaoxu;YANG Wunian;LIN Zhipeng(Key Laboratory of Geoscience Spatial Information Technology of Ministry of Land and Resources,Chengdu University of Technology,Chengdu 610059,China;College of Earth Sciences,Chengdu University of Technology,Chengdu 610059,China;Sichuan Electric Power Design & Consulting Co.,Ltd.,Chengdu 610016,China)

机构地区：[1]成都理工大学国土资源部地学空间信息技术重点实验室,成都610059 [2]成都理工大学地球科学学院,成都610059 [3]四川电力设计咨询有限责任公司,成都610016

出　　处：《测绘科学》2019年第9期13-18,共6页Science of Surveying and Mapping

摘　　要：针对传统等值线的生成是根据离散点利用凸包作为构建TIN的边界,采用等值线追踪的方法进行生成,然后再进行等值线光滑、添加相应注记等以完成等值线图的绘制,存在效率不高,待删除的冗余三角形较多等问题,该文提出了一种以凹包作为由离散点构建TIN的边界,将所有三角形中等值线段生成之后,再整体进行相邻线段合并成多段线折线的方法进行等值线生成,减少了冗余三角形。经过实际验证表明,此法不仅能够满足等值线的快速生成,而且对于狭长型地带或大数据量时其优势更加明显,能够有效降低劳动强度,并且此法简单易行,能够满足实际的生产需要。The traditional method of generating the contour is to use the convex hull as the boundary of constructing TIN for discrete points,and the contour trace method is used to generate the contour,then smooth,add corresponding annotations,etc.But there is no efficiency,to be deleted more redundant triangles problems,this paper proposes a contour generation method based on the concave hull as the boundary of constructing TIN for discrete points,to generate the contours in all the triangles and then merge into the polylines,it can reduce redundant triangles.After actual verification shows that this method can not only meet the contours of the rapid generation,but also for the narrow strip or large amount of data when its advantages are more obvious,can effectively reduce labor intensity.This method is simple,and able to meet actual production needs.

关 键 词：凸包 凹包 TIN 等值线 等值线段连接 

分 类 号：P208[天文地球—地图制图学与地理信息工程]