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Deleting points with special colors from whole scene

Posted: Tue May 14, 2019 2:54 pm
by Chosster
Hello everybody,

I´m dealing with point clouds that were generated from savanna trees by using a handheld LiDAR device. I am only interested in the wooden biomass and not in the biomass of leaves and surrounding grasses. Therefore, I had the idea to delete all green points that represent leaves or grasses from my point clouds and then export the new scene into CompuTree for further measurements of the volume, height and diameter of the trees.

Is there any chance to delete all green points from the whole point cloud by using CloudCompare?

I would be really happy if anybody could help me solving my problem!

Best regards,

Chosster

Re: Deleting points with special colors from whole scene

Posted: Wed May 15, 2019 7:40 pm
by daniel
It's not super reliable, but at least you can try that:
- export the green component of RGB color as a new scalar field ('Edit > Colors > Convert to scalar field' then select the 'G' component only)
- then try to filter the points with a high green component (with 'Edit > Scalar fields > Filter by value')

You can interactively find the right threshold by playing with the scalar fields display parameters (the 'Min and Max displayed distances').

And you may also have to export the other fields (red and blue) so as to refine the segmentation and keep (or merge back) the points with high green values but also high blue or red values.

You can also to do even clever things by playing with the "SF Arithmetics" tool (but I'll let you play with it in a creative way ;).