noise_ivf {lidR}

Noise Segmentation Algorithm

Description

This function is made to be used in classify_noise. It implements an algorithm for outliers (noise) segmentation based on isolated voxels filter (IVF). It is similar to lasnoise from lastools. The algorithm finds points that have only a few other points in their surrounding 3 x 3 x 3 = 27 voxels.

Usage

ivf(res = 5, n = 6)

Arguments

res

numeric. Resolution of the voxels

n

integer. The maximal number of 'other points' in the 27 voxels

See Also

Other noise segmentation algorithms: noise_sor

Examples

LASfile <- system.file("extdata", "Topography.laz", package="lidR")
las <- readLAS(LASfile, filter = "-inside 273450 5274350 273550 5274450")

# Add some artificial outliers
set.seed(314)
id = round(runif(20, 0, npoints(las)))
set.seed(42)
err = runif(20, -50, 50)
las$Z[id] = las$Z[id] + err

las <- classify_noise(las, ivf(5,2))