When a raster dataset has a bimodal distribution, this function creates a new raster that divides the data into two distinct classes. It creates a low value class displayed with black pixels, and a high value class displayed with white pixels.
The algorithm used is the Otsu method, which was designed to distinguish between the background and foreground in imagery and create two classes with minimal intra-class variance (Otsu 1979).
The input raster.
Otsu, Nobuyuki, A Threshold Selection Method from Gray-Level Histograms, IEEE Transactions on Systems, Man, And Cybernetics 9, no. 1 (1979): 62–66.