R lidR compute tree crown width

Question

I have a LiDAR tile with segmented which includes respective tree IDs using silva2016. Now, I am looking for a way to compute the crown widths of each of the segmented trees.

How or which metric can I use to do this?

Purpose: In ArcGIS Pro 3 you can use the Draw preset layers tool to render Realistic Trees in 3D on a map. This tool requires height and crown width information of each tree. I have ztop but don't have the crown width information.

Area:

ITD:

Segmented LAS via silva2016:

Draw preset layers

Code:

library(lidR)

LAS_TreeID = segment_trees(LAS , 
                           silva2016(CHM_pitfree,
                           CHM_pitfree.TTops_Manual2)) # segment point cloud

Answer 1

In absence of a clear definition of the radius/width of objects that are not circular we can assume they are almost circular i.e. the convex hull of each tree is not to far from a circle. In this case the radius can be approximated by sqrt(A/pi).

library(lidR)
LASfile <- system.file("extdata", "MixedConifer.laz", package="lidR")
trees <- readLAS(LASfile, filter = "-drop_z_below 0")
metrics <- crown_metrics(trees, .stdtreemetrics)
metrics$radius = sqrt(metrics$convhull_area/pi)

For a more complex definition, we need... a definition.