Glossary for Geospatial Science

threshold: (binary)  The separation point for converting grayscale raster cell data into binary (black and white) data.  For a raster object scanned with 256 levels of gray, a threshold might be set at 180.  Then the output binary raster object would have a 1 for every cell in the input raster object that had the value 180 or higher, and 0 everywhere else.