'ForestTools' tree top detection

Implements the variable window filter algorithm (Popescu & Wynne, 2004) for detecting treetops from a canopy height model. Andrew Plowright: R package ForestTools

treepos_FT(
  chm = NULL,
  winFun = function(x) {
     0.5 * ((x^2) * 0.009 + 2.51)
 },
  minTreeAlt = 2,
  maxCrownArea = maxCrownArea,
  verbose = TRUE
)

Arguments

chm

Canopy height model in raster, lasmetrics, matrix or object of class LAS. Should be the same that was used to create the input for treepos.

winFun

function. The function that determines the size of the window at any given location on the canopy. It should take the value of a given CHM pixel as its only argument, and return the desired radius of the circular search window when centered on that pixel.

minTreeAlt

Height threshold (m) below a pixel cannot be a local maximum. Local maxima values are used to define tree tops.

maxCrownArea

numeric. A single value of the maximum individual tree crown radius expected.

verbose

quiet (1) height of treepos.

Value

raster* object

Examples

##- required packages
 require(uavRst)

 data(chm_seg)
 
##- call ForestTools treepos function
 tposFT <- treepos_FT(chm = chm_seg[[1]],
            minTreeAlt = 10,
            maxCrownArea = 150)
#> Checking inputs 
#> Creating windows 
#> Detecting local maxima 
            
##- visualize it
# mapview::mapview(tposFT)
raster::plot(tposFT)