Segmenting tree clouds: need some suggestions
Dear Forum,
I’m trying to segment a lot of trees of an 1 hectare big forest plot. Since segmenting it all at once is not feasible, because it is to much data, I decided to devide my original point cloud in smaller subclouds.
I know the exact position of every tree in that plot and hence I cropped a 30m hexagon shaped plot out of the original (did that with CloudCompare and a very useful command line script which I came up with [CMD.exe on windows]).
Now I have over 800 30m plots and my “target” tree is exactly in the center of that plot.
Then I created a script using the tutorials to segment and export the tree in the center of that plot to an individual point cloud.
1. create a list of files to load
2. create loop
3. load file using readers
4. classify ground points
5. create DTM
6. extract a slice parallel to the DTM
7. create 2D positions from point density
8. create point voxel grid
9. create seed voxel grid
10. segment using seed voxel grid
11. Modify voxel grid segmentation # to check whether the segmentation was successful ##I only keep validate trees
12. segment a scene using indices grid
13. export the segmented tree to xyb file.
This is working actually pretty good, BUT still I think this could be done more robustly.
If you look at the attached pictures I attached, you can see that nearly every tree in that plot is segmented. Is there a way that only the tree in the center gets segmented?
I tried to insert between step 5 and 6 an “Extract points in a part of a bounding box” step so that an small subset (1m in dieameter) is created and used that to create only one seed point. But doing so results that every tree is then a part of one subset (all trees would have the same color).
I tried as well to modify my parameters of seed point size and searching parameters for the clusterization but it is not leading to the desired results.
Do you guys have any suggestions how only the tree in the center of my plot is segmented?
Best TMC
p.s. I attached a sample plot as well.
p.p.s. I could in general decrease the size of my hexagonal plots, but some trees have crows which are about 30 m diameter and I want to include those as well.
p.p.p.s If it would help, I have a list with the exact coordinates of each tree I want to segment.
| Sep_trees_full_30m_plot.PNG (81.5 KB) Sep_trees_full_30m_plot.PNG | |||
| Sep_trees_full_30m_plot_2.PNG (302 KB) Sep_trees_full_30m_plot_2.PNG | |||
| 02_Extract_Trees_Crown_Projections_Script.xsct2 (651 KB) 02_Extract_Trees_Crown_Projections_Script.xsct2 | script for segmenting trees (loop) | ||
| Plot_1.xyb (1.37 GB) Plot_1.xyb |
