利用LiDAR点云强度的十字剖分线法道路提取
Automatic Power Lines Extraction Method from Airborne LiDAR Point Cloud
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摘要: 由于道路与地面在空间上表现相近,因此,仅用空间坐标无法从LiDAR数据中直接提取道路。机载激光扫描系统在获取对象三维信息的同时,也记录了激光经由反射的强度信息,因此能从空间坐标和辐射两个方面表现地物的特性。结合这两种相对独立的信息在激光扫描数据中进行道路提取,提高了提取结果的稳定性。首先利用激光扫描数据的高程滤波去除非地面点;再通过强度信息进行阈值分割得到包含干扰的初始道路区域;然后,利用两组十字剖分线检测初始区域在4个方向的狭长性与宽度一致性,使得狭长状、区域宽度较一致的道路区域同干扰区域具有不同的权值,从而提取真正的道路区域;最终通过对道路区域的细化和平滑,得到道路中心线。实验表明,该方法能够较好地在LiDAR数据中提取出道路并得到道路中心线。Abstract: This paper present a power lines automatic extraction method from airborne LiDAR point cloud. Firstly, ground points are removed by automatic filtering method based on fluctuant feature of terrain. Vegetation points, building points and part pylon points are also removed by dimensionality feature and direction feature. Secondly, 2D Hough transform and least square fitting are used to fit center line equation of power lines. And then, the laser point of each power lines can be obtained by center line equation. In this step, power lines projection overlap in the horizontal plane are considered as well. Finally, block centroid calculation method is used to calculate 3D nodes of each power lines. These nodes are used to output the power lines vector. The experimental result shows that the proposed method can extract complete power lines from airborne LiDAR point cloud. This method has some practical meaning for power line inspection.
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