Table 3 Various RGBIs with its formulas and relevant references are used in this research.

Red pixel percentage (R %)

\(\:\frac{\text{R}}{\text{R}+\text{G}+\text{B}}\)

⁵⁷

Green pixel percentage (G %)

\(\:\frac{\text{G}}{\text{R}+\text{G}+\text{B}}\)

⁵⁷

Blue pixel percentage (B %)

\(\:\frac{\text{B}}{\text{R}+\text{G}+\text{B}}\)

⁵⁷

Green red simple ratio (GR)

\(\:\frac{\text{G}}{\text{R}}\)

⁵⁸

Red blue simple ratio (RB)

\(\:\frac{\text{R}}{\text{B}}\)

⁵⁸

Green blue simple ratio (GB)

\(\:\frac{\text{G}}{\text{B}}\)

⁵⁸

Modified Green Red Vegetation Index (MGVRI)

\(\:\frac{{\left(\text{G}\right)}^{2}-{\left(\text{R}\right)}^{2}}{{\left(\text{G}\right)}^{2}+{\left(\text{R}\right)}^{2}}\)

⁵⁸

Red Green Blue Vegetation Index (RGVBI)

\(\:\frac{\text{G}-\left(\text{B}\text{*}\text{R}\right)}{{\left(\text{G}\right)}^{2}+\left(\text{B}\text{*}\text{R}\right)}\)

⁵⁸

Excess red vegetation index (ExR)

\(\:\left(1.4\text{*}\text{R}\right)-\text{G}\)

⁵⁹

Excess green vegetation index (ExG)

\(\:\left(2\text{*}\text{G}\right)-\text{R}-\text{B}\)

⁵⁹

Excess green minus Excess red index (ExGR)

\(\:\text{E}\text{x}\text{G}-\text{E}\text{x}\text{R}\)

⁵⁹

Vegetative index (VEG)

\(\:\frac{\text{G}}{{\text{R}}^{\text{a}}\text{*}{\text{B}}^{\left(1-\text{a}\right)}},\:\text{a}=0.667\)

⁶⁰

Color Index of Vegetation Extraction (CIVE)

\(\:\left(0.441\text{*}\text{R}\right)-\left(0.811\text{*}\text{G}\right)+\)

(\(\:0.385\text{*}\text{B})+18.78745\)

⁶¹

Combination (COM)

\(\:\left(0.25\text{*}\text{E}\text{x}\text{G}\right)+\left(0.3\text{*}\text{E}\text{x}\text{G}\text{R}\right)+\)

\(\:\left(0.33\text{*}\text{C}\text{I}\text{V}\text{E}\right)+\left(0.12\text{*}\text{V}\text{E}\text{G}\right)\)

⁶²

Visible atmospherically resistant index (VARI)

\(\:\frac{(\text{G}-\text{R})}{(\text{G}+\text{R}+\text{B})}\)

⁶³

Green-red vegetation index (GRVI)

\(\:\frac{(\text{G}-\text{R})}{(\text{G}+\text{R})}\)

⁶⁴

Normalized difference index (NDI)

\(\:128\text{*}[\left(\frac{\text{G}-\text{R}}{\text{G}+\text{R}}\right)+1]\)

⁶⁵

Triangular Greenness Index (TGI)

\(\:\text{G}-\left(0.39\text{*}\text{R}\right)-\left(0.61\text{*}\text{B}\right)\)

⁶⁶

Principal component analysis index (IPCA)

\(\:0.994\text{*}\left(\text{R}-\text{G}\right)+0.961\)

\(\:\text{*}\left(\text{G}-\text{B}\right)+0.914\text{*}(\text{G}-\text{R})\)

⁶⁷

Green Leaf Index (GLI)

\(\:\frac{\left(2\text{*}\text{G}\right)-\text{R}-\text{B}}{\left(2\text{*}\text{G}\right)+\text{R}+\text{B}}\)

⁶⁸

Modified Excess Green Index (MExG)

\(\:\left(1.262\text{*}\text{G}\right)-\left(0.884\text{*}\text{R}\right)-\left(0.311\text{*}\text{B}\right)\)

⁶⁹