Fig. 1. Flow diagram of proposed method

Fig. 2. Local extreme point detection

Fig. 3. Search results of local extreme points. (a) Clustering result of connectivity growth; (b) three-dimensional clustering diagram of branches and trunks; (c) clustering status of branches and trunks; (d) result of extracting tree vertices

Fig. 4. Schematics of density contour. (a) Schematic of under-segmented two-dimensional density contours; (b) schematic of under-segmented three-dimensional density contours

Fig. 5. Schematics of under-segmentation. (a) Result of low vegetation segmentation; (b) result of double tree segmentation; (c) result of three wood tree segmentation

Fig. 6. TLS point cloud data. (a) Sample 1; (b) sample 2; (c) sample 3

Fig. 7. Single tree segmentation results in this study. (a) Sample 1; (b) sample 2; (c) sample 3

Fig. 8. Segmentation results by different single tree segmentation methods

Fig. 9. Single tree extraction result of mixed woodland. (a) 3D point cloud data of mixed woodland; (b) segmentation result of proposed method