2.54. Normalized difference index
The tool calculates the normalized difference index for any two input images.
Inputs:
First component of the difference index
Any GDAL-compatible raster
Second component of the difference index
Any GDAL-compatible raster
Outputs:
A raster with normalized difference index in GeoTiff format
The calculation is carried out according to the formula: (First image - Second image) / (First image + Second image). The pixel values of the resulting raster are in the range from -1 to 1 Before the calculation, both images are brought into a single spatial domain. The projection and spatial resolution of the first raster is used.
Examples of common normalized difference indices:
NDVI - for vegetation assessment (the first raster - NIR, the second - RED) For Landsat 8 data: 5 and 4 bands.
NDWI - for the detection of water bodies (the first raster - NIR, the second - SWIR). For Landsat 8 data: 5 and 6 bands.
NDSI - for assessing the snow cover (the first raster - GREEN, the second - SWIR). For Landsat 8 data: 3 and 6 bands.
Launch tool: https://toolbox.nextgis.com/operation/ndi
Try it out using our sample:
Download input dataset to test the instrument. Step-by-step instructions included.
Get the output to additionally check the results.