Table 2 Details of visible and thermal indices used.
S.No | Name | Abbreviation | Definition | References |
|---|---|---|---|---|
Visible indices | ||||
Red | R | Red (0–255) | - | |
Green | G | Green (0–255) | - | |
Blue | B | Blue (0–255) | - | |
Normalised Red | r | \(\text{R/(R+G+B)}\) | Xu et al. 2010 | |
Normalised green | g | \(\text{G/(R+G+B)}\) | Xu et al. 2010 | |
Normalised blue | b | \(\text{B/(R+G+B)}\) | Xu et al. 2010 | |
Colour intensity index | INT | \(\text{(R + G + B)/3}\) | Ahmad and Reid, 1996 | |
Green red difference | GRD | \({\text{G}}\text{-R}\) | - | |
Blue red difference | BRD | \({\text{B}}\text{-R}\) | - | |
Green blue difference | GBD | \(\text{G-B}\) | Xu et al. 2010 | |
Green red ratio index | GRRI | \(\text{G/R}\) | - | |
Green blue ratio index | GBRI | \(\text{G/B}\) | - | |
Red blue ratio index | RBRI | \(\text{R/B}\) | - | |
Woebbecke index | WI | \(\text{(G-B)/(R-G)}\) | Woebbecke et al. 1995 | |
Green–red vegetation index | GRVI | \(\text{(G-R)/(G+R)}\) | Hunt et al. 2005 | |
Kawashima index | IKAW | \(\text{(R-B)/(R+B)}\) | Kawashima and Nakatani, 1998 | |
Normalized Difference Turbidity Index | NDTI | \(\text{(R-G)/(R+G)}\) | Lacaux et al. 2007 | |
GBI | \(\text{(G-B)/(G+B)}\) | - | ||
NGRDI | \(\text{(}\text{G-R}\text{)/(R+G+B)}\) | - | ||
NBRDI | \(\text{(}\text{B-R}\text{)/(R+G+B)}\) | - | ||
NGBDI | \(\text{(G-B)/(R+G+B)}\) | - | ||
Green leaf index | GLI | \(\text{(2g-b-r)/(2g-b-r)}\) | Louhaichi et al. 2001 | |
Visible atmospherically resistant index | VARI | \(\text{(g-r)/(g+r-b)}\) | Gitelson et al. 2002 | |
Normalized difference index | NDI | \(\text{(g-r)/(g+r)}\) | Woebbecke et al. 1995 | |
Gray | Gray | \(0.2898 \times r + 0.5870 \times g + 0.1140 \times b\) | Kazmi et al. 2015 | |
Brightness index | BI | \(\sqrt{{(R}^{2}{+G}^{2}+{B}^{2})/3}\) | Levin et al., 2005 | |
Hue index | HI | \({(2} \times {\text{R - G - B)/(G - B)}}\) | Levin et al. 2005 | |
Redness index | RI | \({\text{R}}^{2} {\text{/(B}} \times {\text{G}}^{3} {)}\) | Levin et al. 2005 | |
Saturation index | SI | \({2 } \times {\text{ (R - G - B)/(G - B)}}\) | Levin et al. 2005 | |
Colouration index | CI | \(\text{(R - B) / R}\) | Levin et al., 2005 | |
Color index of vegetation | CIVE | \({0}{\text{.441}} \times {\text{R - 0}}{.811} \times {\text{G + 0}}{.385} \times {\text{B + 18}}{.78745}\) | Kataoka et al. 2003 | |
Vegetative Index | VEG | \(\text{G/(}{R}^{0.667}{B}^{0.334}\text{)}\) | Hague et al. 2006 | |
Excessive green index | ExG | \(\text{2g-r-b}\) | Meyer et al. 1999 | |
Excessive red | ExR | 1.4r-g | Meyer et al. 1999 | |
Excessive green index minus excess red index | ExGR | 3g-2.4r-b | Meyer et al. 2004 | |
Modified Excess Green Index | MxEG | \(\text{1.262G-0.884R-0.311B}\) | Burgos-Artizzu et al. 2011 | |
Excessive blue | ExB | 1.4 × b-g | Wenhua Mao et al. 2003 | |
Principal component analysis index | IPCA | \(\text{0.994 (R - B) + 0.961 (G-B) + 0.914 (G-R)}\) | Saberioon et al. 2014 | |
Red green blue VI | RGBVI | \({(}G^{2} {\text{ - (R}} \times {\text{B))/(}}G^{2} {\text{ + (R}} \times {\text{B))}}\) | Bending et al. 2015 | |
GLAI | \({(25 } \times {\text{ (G - R)/(G + R - B) + 1}}{.25 )}\) | - | ||
Overall Saturation Index | SAT | \(\text{(max(R,G,B) - min(R,G,B)) / max(R,G,B)}\) | - | |
OHI | \({\text{atan(2 }} \times {\text{ (R - G - B) / 30}}{.5 } \times {\text{ (G - B))}}\) | - | ||
True Color Vegetation Index | TCVI | 1.4 × (2R-2B)/(2R- G-2B + 255 × 0.4) | - | |
Combined Indices 1 | COM1 | \(\text{ExG + CIVE + ExGR + VEG}\) | Guijarro et al. 2011 | |
Combined Indices 2 | COM2 | \({0}{\text{.36}} \times {\text{ExG + 0}}{.47} \times {\text{CIVE + 0}}{.17} \times {\text{VEG}}\) | Guerrero et al. 2012 | |
