Function of Mask (Fmask), is a classification process that categorises pixels into mutually exclusive classes. The classes are defined as an enumerator with values 0 -> 5.
The Fmask algorithm works across Landsat's 4, 5, 7 and 8, as well as Sentinel-2 A & B. The algorithms may differ per sensor, but the classification schema is standardised across all platform's/sensors.
The classes/categories are:
- Unclassified -> 0
- Clear -> 1
- Cloud -> 2
- Cloud Shadow -> 3
- Snow -> 4
- Water -> 5
Further details on the algorithm can be found here:
A Python implementation of the algorithm written by Neil Flood, can be found here: