zonal_mask: Divide a raster image into four stacks which are used as masks.
Description
This function imports a SpatRaster image using terra::rast() functionality, and divide into four masks, using the image centre and borders as vertices.
The four zonal masks are then returned as a RasterStack.
Usage
zonal_mask(img)
Value
A 4-layers stacks of image masks
Arguments
img
SpatRaster. The input single layer image generated from terra::rast().