Summary
Calculates the Normalized Difference Vegetation Index (NDVI) from a multiband raster object and returns a raster object with the index values.
Discussion
The Normalized Difference Vegetation Index (NDVI) method 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 NIR band.
NDVI = ((NIR - Red)/(NIR + Red))- NIR = pixel values from the near-infrared band
- Red = pixel values from the red band
This index outputs values between -1.0 and 1.0.
For information about other multiband raster indexes, see the Band Arithmetic raster function.
The referenced raster dataset for the raster object is temporary. To make it permanent, you can call the raster object's save method.
Syntax
NDVI (raster, {nir_band_id}, {red_band_id})| Parameter | Explanation | Data Type |
raster | The input raster. | Raster |
nir_band_id | The band ID of the near-infrared band. The ID index uses one-based indexing. (The default value is 4) | Integer |
red_band_id | The band ID of the red band. The ID index uses one-based indexing. (The default value is 3) | Integer |
| Data Type | Explanation |
| Raster | The output raster object with the NDVI index values. |
Code sample
Calculates the Normalized Difference Vegetation Index for a Landsat 8 image.
import arcpy
NDVI_raster = arcpy.ia.NDVI("Landsat8.tif", 5, 4)