To calculate the vegetation indices. This class contain the following functions:
get_vi => To get the Vegetation Indices.
The followign indices can be calculated :
RVI
NDVI
IPVI
DVI
RNDVI
MRVI
MPRI
SAVI
EVI2
MGNDVI
MNDVI
BI
RGRI
GNDVI
NDRGI
NDVSI
RDI
TNDVI
GRVI
OSAVI
MGRVI
SLAVI
NDMI