Algorithm description
The algorithm used to determine the equivalent number of looks is pretty simple and it should be used only on isolated homogeneous salt and pepper like portions of the raster data:
\[
ENL = \frac{I_{mean}^2}{I_{std}^2}
\]
The algorithm used to determine the equivalent number of looks is pretty simple and it should be used only on isolated homogeneous salt and pepper like portions of the raster data: