Mosaic Index — mosaic_index • pliman

Compute or extract an index layer from a multi-band mosaic raster.

Usage

mosaic_index(mosaic, index = "R", r = 3, g = 2, b = 1, re = 4, nir = 5)

Arguments

mosaic: A mosaic of class SpatRaster, generally imported with mosaic_input().
index: The index to use for the index view. Defaults to "B".
r: The layer for the Red band (default: 3).
g: The layer for the Green band (default: 2).
b: The layer for the Blue band (default: 1).
re: The layer for the Red-edge band (default: 4).
nir: The layer for the Near-infrared band(default: 5).

Value

An index layer extracted/computed from the mosaic raster.

Details

This function computes or extracts an index layer from the input mosaic raster based on the specified index name. If the index is not found in the package's predefined index list (see image_index() for more details), it attempts to compute the index using the specified band indices. The resulting index layer is returned as an SpatRaster object.

Examples

library(pliman)
library(terra)
#> terra 1.7.55
#> 
#> Attaching package: 'terra'
#> The following object is masked from 'package:pliman':
#> 
#>     distance
mosaic <- mosaic_input(system.file("ex/elev.tif", package="terra"))
confusion <-
     matrix(rnorm(90*95, 100, 30),
            nrow = nrow(mosaic),
            ncol = ncol(mosaic))
confusion <- mosaic_input(confusion)
terra::ext(confusion) <- terra::ext(mosaic)
terra::crs(confusion) <- terra::crs(mosaic)
names(confusion) <- "confusion"
two_layers <- c(mosaic, confusion)
final <- mosaic_index(two_layers, "B+R", b = 1, r = 2)
#> Index 'B+R' is not available. Trying to compute your own index.
mosaic_view(mosaic_input(final), viewer = "base")