script.js

// Enhanced Vegetation Index  (abbrv. EVI)
// General formula: 2.5 * (NIR - RED) / ((NIR + 6*RED - 7.5*BLUE) + 1)
// URL https://www.indexdatabase.de/db/si-single.php?sensor_id=96&rsindex_id=16

let EVI = 2.5 * (B08 - B04) / ((B08 + 6.0 * B04 - 7.5 * B02) + 1.0);

if (EVI<-1.1) return [0,0,0];
else if (EVI<-0.2) return [0.75,0.75,0.75];
else if (EVI<-0.1) return [0.86,0.86,0.86];
else if (EVI<0) return [1,1,0.88];
else if (EVI<0.025) return [1,0.98,0.8];
else if (EVI<0.05) return [0.93,0.91,0.71];
else if (EVI<0.075) return [0.87,0.85,0.61];
else if (EVI<0.1) return [0.8,0.78,0.51];
else if (EVI<0.125) return [0.74,0.72,0.42];
else if (EVI<0.15) return [0.69,0.76,0.38];
else if (EVI<0.175) return [0.64,0.8,0.35];
else if (EVI<0.2) return [0.57,0.75,0.32];
else if (EVI<0.25) return [0.5,0.7,0.28];
else if (EVI<0.3) return [0.44,0.64,0.25];
else if (EVI<0.35) return [0.38,0.59,0.21];
else if (EVI<0.4) return [0.31,0.54,0.18];
else if (EVI<0.45) return [0.25,0.49,0.14];
else if (EVI<0.5) return [0.19,0.43,0.11];
else if (EVI<0.55) return [0.13,0.38,0.07];
else if (EVI<0.6) return [0.06,0.33,0.04];
else return [0,0.27,0];