CVI is a derived multi-spectral index for usage with the KolariVision Infrared Blue/NIR NDVI filter (and similar). It is intended to closely parallel the values of leaf-level NDVI (e.g. GreenSeeker), though it currently does not occupy the same domain of values.
CVI has seen numerous revisions, each with the intent of improving the detection of Crop Vigor, especially against bare soil.
Schott BG3
Band 1 - Red - High IR Reflectance
Band 2 - Green - Low IR reflectance, mostly ground/non-vegetative returns
Band 3 - Blue - Medium IR reflectance, good ground/non-vegetative returns
Blue light will map to the blue channel.
Near IR from 700-800 will map to the red channel primarily.
Light from the 850-1000nm band will map to red, blue, and green, but you have much less sensitivity in the 850-1000 range than 700-800 range, so it is a minority of the signal.
Effectively, blue=B, IR=R.
Trying: (NIR+BLUE)-(Green)/(NIR+BLUE)+(GREEN)
The below methods assume that a typical tri-band visible sensor (RGB) is being used with a full-spectrum conversion alongside the application of either an internal or external KolariVision Infrared Blue/NIR NDVI filter.
Linear Averaging
((R + G + B)) / 3
CVI: Version 1
((R + B) - (G) / (R + B) + (G)) / 3
CVI: Version 2
((R + G) - (B) / (R + G) + (B)) / 3
CVI: Version 3
1/((((R + B) - (G)) / ((R + B) + (G))) / 3)
CVI: Version 4
((((R + G)/2) - B))/((((R + G)/2) + B))
CVI: Version 5
1/((((R + B) - (G)) / ((R + B) + (G))))
CVI: Version 6
((R + G) - (2 * B)) / ((R + B) + (2 * B))
CVI: Version 7
((R + B) - (G) / ((R + B) + (G))) / 3
CVI: Version 8
((((R + B)/2) - G))/((((R + B)/2) + G))
CVI: Version 9
((((R + B) - (G)) / ((R + B) + (G))) / 3)
CVI: Version 10
(R + B) - ((G) / ((R + B) + (G))) / 3
CVI: Version 11
((R + B) + (G)) / ((R + B) - (G))
