基于机载LiDAR点云数据的历史文化街区重建方法研究

为了提高历史街区重建过程中建筑物轮廓与实际建筑物激光脚点的吻合精度，提出了一种基于机载LiDAR点云数据的历史文化街区重建方法。首先，对机载LiDAR点云数据作预处理，去除点云数据中的噪声。其次，利用区域生长算法对激光脚点作分割，完成建筑物点云数据的获取。之后，采用Alpha Shape算法提取建筑物特征信息，得到轮廓线，再通过管子算法将轮廓线规则化。针对多边形轮廓线，采用分类强制正交法对其作规则化。最后，通过平面拟合、直线拟合等方法，对历史文化街区进行三维重建。结果表明，所提出的重建方法在提取建筑物轮廓时，激光脚点吻合更精确，并且重建耗时为25 min，优于文献所提的2种方法。基于机载LiDAR点云数据的历史文化街区重建方法，可以在一定程度上提高历史文化街区的重建质量，并为其他历史文化街区的保护与更新提供借鉴。

Reconstruction method of historical and cultural blocks based on airborne LiDAR point cloud data

In order to improve the matching accuracy of building outlines and actual building laser foot points in the process of historical block reconstruction, a reconstruction method of historical and cultural blocks based on airborne LiDAR point cloud data was proposed. Firstly, the airborne LiDAR point cloud data were preprocessed to remove the noise in the point cloud data. Secondly, the region growing algorithm was used to segment the laser foot points to complete the acquisition of building point cloud data. Afterwards, the Alpha Shape algorithm was used to extract the feature information of the building, and the contour line was obtained, and then the contour line was regularized by the pipe algorithm. Aiming at polygonal contour lines, the method of classifying and forcing orthogonality was used to regularize them. Finally, through plane fitting, straight line fitting and other methods, the historical and cultural blocks were reconstructed in three dimensions. The results show that the proposed reconstruction method is more accurate in extracting building outlines than laser foot points. And the reconstruction time is 25 minutes, which is better than the two methods mentioned in the literature. The reconstruction method of historical and cultural blocks based on airborne LiDAR point cloud data can improve the reconstruction quality of historical and cultural blocks to a certain extent, and provides reference for the protection and renewal of other historical and cultural blocks.