顾及地形特征的机载LiDAR数据桥梁提取算法研究
Extracting Bridges from Airborne LiDAR Data Based on Terrain Features
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摘要: 提出了一种从机载LiDAR点云数据中提取水陆桥梁的新算法,采用先滤波分类再识别桥梁的策略用于桥梁主体及其与地面连接处脚点的提取。首先对机载LiDAR点云数据进行严格滤波,在此基础上利用多个阈值对非地面脚点进行初步提取;然后引入Alpha-shapes算法对初步提取结果进行分割,并辅以面积阈值提取出属于桥梁主体部分的脚点;最后提出一种顾及地形特征的点云区域生长算法,用于准确提取桥梁主体与地面连接部分的脚点。实验证明,本文算法对水面和陆地桥梁提取均有很好的效果。Abstract: A new method for extracting bridges from airborne LiDAR data based on terrain features is proposed.A filtering-recognizing strategy is implemented.Firstly,an initial extraction is implemented on non-ground laser footprints that are labelled by a prior filtering algorithm with strict criterions.Then,an Alpha-shapes algorithm is introduced to segment the initial extraction results.Among the segments,those who belong to the main bridge body are identified by using an area threshold.Finally,a region growing algorithm based on terrain features is proposed to accurately extract the laser footprints on the bridge-ground connecting sections.The experiments are conducted to demonstrate the efficiency of the proposed method both on water and land bridges dataset.