Table 4. Formulas of vegetation indices.

VI	Formulaa, b	Ref
EXG	2g−r−b	[20]
EXR	1.4r−g	[20]
NDI	(g−r)/(g+r)	[20]
EXGR	3g−2.4r−b	[20]
GLI	(2g−b−r)/(2g+b+r)	[21]
VARI	(g−r)/(g+r−b)	[21]

^a R = red band (630–690 nm), G = green band (520–600 nm), B = blue band (420–450 nm).

^b r = R/(R+G+B), g = G/(R+G+B), b = B/(R+G+B).