Export classification LiDAR to raster

Question

I'd like to export the LiDAR data according to their classification in a georeferenced raster format. Something that look like that:

Here is the code that I tested to retrieve the classification:

nonveg <- filter_poi(las, Classification != LASHIGHVEGETATION)
veg <- filter_poi(las, Classification == LASHIGHVEGETATION)

x <- plot(nonveg, color = "Classification", bg = "white", size = 3)
plot(veg, add = x)`

Answer 1

Well, without more details I'd say it is not possible because in a given cell you may have points with different classes e.g. low vegetation + high vegetation + ground. Consequently for a given cell you must make a choice to retain only one class. Here I will assume you want to retain the class that is represented by more numerous points. So you want Mode(Classification)

library(lidR)
LASfile <- system.file("extdata", "Megaplot.laz", package="lidR")
las = readLAS(LASfile)

Mode <- function(x) {
  ux <- unique(x)
  return(ux[which.max(tabulate(match(x, ux)))])
}

map = grid_metrics(las, ~Mode(Classification), 1)
plot(map)

Here the output is not very interesting because there are only "ground" and "non classified" in this dataset.