The TGI operator algorithm computes the Triangular Greenness Index from a given product.

The TGI results from the following equation:

TGI = - 0.5 * (190 * (R - G) - 120 * (R - B))

, where:

The bands are:

- B is the Blue band
- G is the Green band
- R is the Red band

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

Bit Position	Description
Bit 0	The computed value for TGI is NAN or is Infinite
Bit 1	The computed value for TGI is less than -1 (minus one)
Bit 2	The computed value for TGI is greater than 1 (one)