关键词: 机载点云, 采样线滤波, 断裂线约束, 局部曲面拟合

Abstract: The existing filtering methods often mistakenly filter a large number of ground points in areas with complex terrain and abrupt elevation, which reduces the accuracy of filtering results and seriously affects the subsequent application. For this reason, this paper proposes an efficient filtering method for sampling lines by fusing the breakline constraint model. Firstly, a constraint energy term is created based on the sum of point curvature and distance in the neighborhood, and the Snake energy model is improved, and features of breaklines are extracted by minimizing the energy function. Then, the point cloud sequence is obtained from the survey area to form a sampling line at equal intervals, and the regular triangle model is constructed, the flatness of point clouds is calculated, and the points on each sampling line are filtered by fusing the breakline constraint. Finally, according to ground points on the sampling line, the improved least square method is used to fit global surface, and the non ground points in the region are filtered according to their actual elevation values. In order to verify the effectiveness of this method, this paper uses five airborne laser point cloud data from different regional scenes for experimental analysis. The results show that the proposed method is better than the reference method in terms of efficiency and accuracy, and the average filtering accuracy is as high as 96.58%, especially in the terrain fault area.

Key words: airborne point clouds, sampling line filtering, breaklines constraint, local surface fitting