BI Algorithm Specification

BI

The Brightness Index algorithm is representing the average of the brightness of a satellite image.

The result looks like a panchromatic image with the same resolution of the original image.
This index is therefore sensitive to the brightness of soils which is highly correlated with the humidity and the presence of salts in surface (Escadafal, 1989).

The BI results from the following equation:

BI = sqrt( ( (red_factor * red * red_factor * red) + (green_factor * green * green_factor * green) ) / 2 )

BI-Flags

Also the processor computes an additional flags band called 'bi_flags' with the following bit coding:

Bit PositionDescription
Bit 0The computed value for BI is NAN or is Infinite
Bit 1The computed value for BI is less than 0 (zero)
Bit 2The computed value for BI is greater than Floating Point Maximum Value