OtsuSeg (version 0.1.0)

binarize_raster: Binarize a Raster Using Otsu's Thresholding (with Inter-Class and Intra-Class Variance)

Description

This function computes deltaNBR (difference between post-fire and pre-fire NBR), rescales it, applies a smoothed histogram, and uses Otsu's thresholding to create a binary raster representing burn scars. It also generates and saves plots of the smoothed histogram, inter-class variance curve, and the inter-class and intra-class variance curves on separate plots.

Usage

binarize_raster(
  x,
  y,
  output_shapefile = TRUE,
  shapefile_path = "binary_raster.shp"
)

Value

A list containing:

best_threshold

Numeric. The computed Otsu threshold value.

area_hectares

Numeric. The estimated burned area in hectares.

binary_raster_smoothed

RasterLayer. The binary raster created using the Otsu threshold.

binary_shapefile

sf object. The binary shapefile created, if output_shapefile is TRUE.

shapefile_path

Character. Path where the shapefile was saved, if output_shapefile is TRUE.

Arguments

x

RasterLayer. A raster layer object representing pre-fire NBR (e.g., `raster::RasterLayer`).

y

RasterLayer. A raster layer object representing post-fire NBR (e.g., `raster::RasterLayer`).

output_shapefile

Logical. If TRUE, saves the binary raster as a shapefile. Default is TRUE.

shapefile_path

Character. Path to save the shapefile. Used only if output_shapefile is TRUE.

Examples

if (FALSE) { # interactive()
#For CRAN checks, a temporary directory is used to avoid leaving files.
#For permanent use, specify a path like "results/binary_raster.shp"
  pre_fire <- get_external_data("NBRpre.tif", load = TRUE)
  post_fire <- get_external_data("NBRpost.tif", load = TRUE)
  shapefile_path <- file.path(tempdir(), "binary_raster.shp")
  result <- binarize_raster(pre_fire, post_fire, shapefile_path = shapefile_path)
  print(result$area_hectares)
  # Clean up (optional)
  unlink(list.files(tempdir(), pattern = "binary_raster\\.(shp|shx|dbf|prj)$", full.names = TRUE))
}