Table 1.

The VI evaluated in this study. R, G, B indicated normalized red, green, and blue bands, respectively. Note: α was a constant as 0.667.

Index	Name	Equation	Reference
E1	EXG	$2\times G-R-B$	[50,51]
E2	EXR	$1.4\times R-G$	[52]
E3	VDVI	$\left(2\times G-R-B\right)/\left(2\times G+R+B\right)$	[53,54,55,56]
E4	EXGR	$2\times G-R-B-1.4\times R-G$	[57]
E5	NGRDI	$\left(G-R\right)/\left(G+R\right)$	[55,58]
E6	NGBDI	$\left(G-B\right)/\left(G+B\right)$	[54,59]
E7	CIVE	$0.441\times R-0.8818G+0.385\times B+18.787$	[60,61]
E8	CRRI	$G/R$	[62,63,64]
E9	VEG	$G/R^{\alpha }{B}^{1-\alpha }$	[65,66]
E10	COM	$0.25EXG+0.3EXGR+0.33CIVE+0.12VEG$	[67,68]
E11	RGRI	$G/B$	[69,70]
E12	VARI	$\left(G-R\right)/\left(G+R-B\right)$	[71,72]
E13	EXB	$1.4\times B-G$	[67,73]
E14	MGRVI	$\left(G\times G-R\times R\right)/\left(G\times G+R\times R\right)$	[74,75]
E15	WI	$\left(G-B\right)/\left(R-G\right)$	[72,76]
E16	IKAW	$\left(R-B\right)/\left(R+B\right)$	[58,77]
E17	GBDI	G − B	[52,78]
E18	RGBVI	(G × G − B × R)/(G × G + B × R)	[79,80,81]