摘要
三维激光扫描仪获得的工业构件点云数据精度高,但是包含大量的冗余点。在保证被测对象几何特征的前提下,对点云数据进行精简,可以提高计算速度,减少存储空间,突出建模特征。本文针对工业构件点云提出了基于曲面变化的点云精简算法,通过计算点的曲面变化将点云分成特征不同的3个区域,对不同点区域设定权值,利用点的曲面变化定义近似特征点阈值,将小于阈值的点按照属于不同的特征区域计算其精简比率,由精简比率定义距离阈值完成精简。利用本文方法对bunny点云、盒子点云、工业零件点云3组数据进行了精简处理,并从算法的精简简度、速度及精度3方面与基于曲率的精简方法进行了比较。结果表明,本文提出的基于曲面变化的工业构件点云精简方法在精简精度上可以达到与基于曲率精简方法相同的效果,且计算速度更快,更好地保持了几何特征;加入边界保护处理后,精简对边界影响也比较小,可以满足后续建模要求。
The point cloud data of industrial components obtained by a 3 D laser scanner has high accuracy to represent the object,but it contains a large number of redundant points. On condition that the geometric characteristics of the measured objects are ensured,simplification of the point cloud data is capable of increasing calculation speed,reducing storage space,and highlighting modeling characteristics. In this paper,a new algorithm based on curved surface variation for the point clouds of industrial components is proposed. By calculating the curved surface variations of points,the point cloud is divided into three zones with different characteristics.Weighting values are set for the point zones. The threshold of approximate characteristic points is defined using the curved surface variations of points. Calculate the simplification rates of those points less than the threshold according to its characteristic zones. Then define the distance threshold based on the simplification rate to finish the simplification. The three groups of data for bunny point cloud,point cloud of a box,and point cloud of an industrial part are simplified using the simplification technique introduced in this paper,i.e.curved surface variation-based simplification technique. In respect of extent,speed,and accuracy of simplification,comparison is made between the curved surface variation-based simplification technique and the curvature-based simplification technique. The comparison shows that the two techniques have the same simplification accuracy but the former overtakes the latter in terms of simplification speed.In addition,the former does better in preserving geometric characteristics. Owing to addition of boundary protection processing,the former has little impact on the boundary and can hence meet the subsequent modeling requirements.
作者
曹爽
赵显富
马文
CAO Shuang;ZHAO Xianfu;MA Wen(School of Remote Sensing ＆ Geomatics Engineering,Nanjing University of Information Science ＆ Technology,Nanjing 210044,China)
出处
《测绘通报》
CSCD
北大核心
2018年第11期20-24,共5页
Bulletin of Surveying and Mapping
基金
国家自然科学基金青年项目(41501501)
关键词
点云精简
工业构件
曲面变化
曲率
几何特征
边界保护
point cloud data simplification
industrial components
curved surface variation
curvature
geometric characteristics
boundary protection
