Summary
Calculates the Normalized Difference Built-up Index (NDBI) from a multiband raster object and returns a raster object with the index values.
Discussion
The Normalized Difference Built-up Index (NDBI) uses the NIR and SWIR bands to emphasize manufactured built-up areas. It is ratio based to mitigate the effects of terrain illumination differences as well as atmospheric effects.
NDBI = (SWIR - NIR) / (SWIR + NIR)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
NDBI (raster, {swir_band_id}, {nir_band_id})| Parameter | Explanation | Data Type |
raster | The input raster. | Raster |
swir_band_id | The band ID of the shortwave infrared band. The ID index uses one-based indexing. (The default value is 6) | Integer |
nir_band_id | The band ID of the near-infrared band. The ID index uses one-based indexing. (The default value is 5) | Integer |
| Data Type | Explanation |
| Raster | The output raster object with the NDBI values. |
Code sample
Calculates the Normalized Difference Built-up Index for a Landsat 8 image.
from arcpy.sa import *
out_ndbi_raster = NDBI("landsat8.tif", 6, 5)
out_ndbi_raster.save("C:/arcpyExamples/outputs/NDBI.tif")Calculates the Normalized Difference Built-up Index for a Landsat 8 image.
# Import system modules
import arcpy
from arcpy.sa import *
# Set the analysis environments
arcpy.env.workspace = "C:/arcpyExamples/data"
# Set the local variables
in_raster = "landsat8.tif"
# Execute NDBI function
out_ndbi_raster = NDBI(in_raster, 6, 5)
# Save the output
out_ndbi_raster.save("C:/arcpyExamples/outputs/NDBI.tif")