filter_OverlappingCrowns: Remove crown area polygons based on spatial overlap with...
In niknap/MeanShiftR: Tree delineation from lidar using mean shift clustering

Description Usage Arguments Value Author(s)

View source: R/filter_OverlappingCrowns_function.R

The AMS3D algorithm can lead to clustering artefacts such that a single tree crown may be assigned to more than one cluster ID and the derived enclosing crown polygons may show very high spatial overlap. This function enables cleaning of the crown polygon dataset by removing redundant polygons which most likely represent just one single tree. Of several overlapping polygons, the polygon with the largest tree height value is kept, while the other polygons are removed. The algorithm involves pairwise comparisons of all polygons which are handed over to the function. Hence, it is recommended to apply it on small tiles (e.g., 1 ha), as processing time may become very slow for large areas.

1	filter_OverlappingCrowns(crowns, overlap.threshold)

`crowns`	SpatialPolygonsDataFrame of crown projection areas, derived from make_CrownPolygons function
`overlap.threshold`	Value between 0 and 1 specifying the relative overlap of a pair of crown projection areas (intersection area of two crowns divided by area of a single crown). If the relative overlap is for both crowns larger than this threshold, the crown polygon with the lower tree height value is removed.

SpatialPolygonsDataFrame with each feature representing the crown projection area of one tree and columns containing various geometric attributes

Nikolai Knapp, nikolai.knapp@ufz.de

niknap/MeanShiftR documentation built on Dec. 20, 2020, 12:32 p.m.