mosaic_chm_mask: Apply a height mask to CHM data

In pliman: Tools for Plant Image Analysis

Apply a height mask to CHM data

Description

This function applies a height-based mask to a Canopy Height Model (CHM), focusing on areas with heights above a specified lower threshold and, optionally, below an upper threshold.

Usage

mosaic_chm_mask(
  dsm,
  lower,
  upper = NULL,
  window_size = c(5, 5),
  interpolation = "Tps"
)

Arguments

dsm	A SpatRaster object representing the digital surface model. Must be a single-layer raster.
lower	A numeric value specifying the lower height threshold. All heights greater than this value are retained.
upper	An optional numeric value specifying the upper height threshold. If provided, only heights between lower and upper are retained.
window_size	An integer (meters) specifying the window size (rows and columns, respectively) for creating a DTM using a moving window. Default is c(10, 10).
interpolation	(optional) A character string specifying the interpolation method to use when points are provided. Options are "Kriging" (default) or "Tps" (Thin Plate Spline).

Details

The mosaic_chm function, used internally, generates the DTM from the DSM by downsampling and smoothing raster data, applying a moving window to extract minimum values and then interpolating the results. The CHM is computed as the height difference between the DSM and DTM. This function calculates and applies a mask based on height thresholds.

Value

An SpatRaster object representing the masked CHM.

pliman documentation built on Aug. 21, 2025, 5:46 p.m.