Using the NDVI button on the Image Analysis window
Using the NDVI button computes the normalized difference vegetation index (NDVI) from a multispectral image or two selected image layers. The NDVI is a standardized index allowing you to generate an image displaying greenness (relative biomass). This index takes advantage of the contrast of the characteristics of two bands from a multispectral raster dataset-the chlorophyll pigment absorptions in the red band and the high reflectivity of plant materials in the near-infrared (NIR) band.
- To view the Image Analysis window, click Windows on the Main menu and click Image Analysis.
If you are selecting a multiband dataset, you can specify which band will be used for the red and infrared inputs by doing the following:
- Click the Options button on the Image Analysis window.
- Click the NDVI tab.
Change the inputs for the Red Band and Infrared Band.
By default the Red Band is 3 and the Infrared Band is 4. You may need to look at the metadata for your imagery to determine which bands to use. If, for example, you have a three-band color infrared image, the Infrared Band may be 1 and the Red Band may be 2.
- Click OK.
- Click a multiband raster or image service layer in the Image Analysis window.
- Optionally select two single-band raster or image service layers in the table of contents.
- Click the NDVI button .