Wood and leaf separation from terrestrial LiDAR point clouds based on mode points evolution

Abstract

To improve the accuracy of wood and leaf points classification for individual tree, this paper proposed a separation method based on mode points evolution from terrestrial LiDAR point clouds. In the proposed method, the Mean Shift method was used to first acquire the mode points, which were then adopted as nodes to build a network graph for the individual tree. By path retracing and calculating the visiting frequency of each node, the wood seed nodes were detected. To obtain more wood nodes, the wood seed nodes were evolved based on three constraints, namely the shortest path length of the evolved nodes to the base node should be smaller, the evolved nodes should not belong to the leaf nodes that have been detected by path retracing and the verticality of the evolved nodes should be similar as the wood seed nodes. After wood nodes evolution, the segments corresponding to each wood seed node were merged together to obtain the final wood points. The proposed method has been evaluated using nine tree samples with seven different tree species. Experimental results showed that the proposed method can achieve an average wood and leaf classification accuracy of 0.892. The average F1 score for wood was 0.871, while the average F1 score for leaf was 0.900. Compared to two other famous wood and leaf classification methods, the proposed method can achieve better classification results.