基于LIDAR数据的建筑轮廓线提取及规则化算法研究  

Algorithms Study of Building Boundary Extraction and Normalization Based on LIDAR Data

作　　者：沈蔚 李京[2] 陈云浩[2] 邓磊[2] 彭光雄[3] 

机构地区：[1]上海水产大学海洋学院,上海200090 [2]北京师范大学资源学院,北京100875 [3]中国科学院遥感应用研究所,北京100101

出　　处：《遥感学报》2008年第5期692-698,共7页NATIONAL REMOTE SENSING BULLETIN

基　　金：国家重大基础研究发展规划项目(编号:2006CB701302);国家自然科学基金(编号:40771136);上海高校选拔培养优秀青年教师科研专项基金(编号:B-8101-08-0021);上海水产大学博士科研启动基金(07-280)

摘　　要：建筑轮廓线提取与规则化是LIDAR数据处理和建筑三维建模的重要步骤和技术难点。首次将"AlphaShapes算法"应用于LIDAR数据处理,实践证明该算法简洁高效、运行稳定、提取精度高,适用于任何形状的建筑轮廓线提取,并具有一定自适应性和滤波功能,非常适合LIDAR点云数据提取建筑轮廓线。同时,提出了改进的"管子算法"用于原始轮廓线的简化,提出了适用于四边形的"矩形外接圆法"和适用于多边形(大于四边且边数为偶数)的"分类强制正交法"以进一步实现轮廓线的规则化,最终解决了离散点云提取规则建筑轮廓线的核心问题。实践证明,本文所述算法适用于凸凹多边形建筑内外轮廓线的提取与规则化。The building boundary extraction and normalization are the key approach for LIDAR data processing and building 3D modeling.In this paper,'Alpha Shapes algorithm' is first applied on the LIDAR data to extract the building boundary.In addition,an enhanced boundary simplifying algorithm,i.e.'Pipe Algorithm' and two other developed normalization algorithms,'Circumcircle Regularization Algorithm' & 'Cluster and Adjustment Algorithm' are used to improve the extracted boundary.Finally,the normalized building boundary is generated perfectly with these algorithms.A limited accumulated points S has an alpha shape in polygon.This polygon is determined by S and α.We can imagine that a circle with an α radius is rolling around the S.When α value is big enough,the circle will not fall into the area of accumulated points.The rolling track will form the boundary of these discrete points(for example LIDAR data).Contrarily,when the α value is very small(α→ 0),every point might be the boundary.When the alpha value is approaching infinity(α→∞),alpha shape will be the convex hull.When the S contains evenly distributed points and α value approaching optimum value,the alpha shape can extract the inner and outer boundary of convex and concave polygon.The boundary obtained from Alpha Shape Algorithm above is rough which can be defined as raw boundary.In this paper,an enhanced simplifying algorithm,i.e.'Pipe Algorithm' is developed to simplify the raw outline which usually is composed of zigzag shape.Pipe Algorithm retrieves the polygon inflexion points based on the changes of angle direction.These inflexion points are retained while the intermediate points are eliminated.The remained inflexion points will establish a basic framework of the polygon.At the same time,two other developed normalization algorithms,Circumcircle Regularization Algorithm & Cluster and Adjustment Algorithm are used to improve the extracted polygon framework.Now,the two normalization algorithms can be applied for four sided and multi-sided polygon(grea

关 键 词：LIDAR 机载激光扫描 建筑轮廓线提取 建筑轮廓线规则化 

分 类 号：TP751[自动化与计算机技术—检测技术与自动化装置] P237[自动化与计算机技术—控制科学与工程]