Part 3: Create a Pansharpened Image Using ArcGIS
Panchromatic sharpening, more commonly called pansharpening, is a process in which two raster datasets are fused together to create one high-resolution, easy to analyze raster dataset. This process utilizes one high-resolution panchromatic image and one lower-resolution multiband color image. By combining these two images, the final product not only has the higher resolution of the panchromatic dataset, but it also has the color associated with the multiband dataset, providing the user with better analysis opportunities.
Where to begin:
In this example, pansharpening was applied to a mosaic dataset contained within a file geodatabase. The imagery featured in this example was collected using the Quickbird satellite. Mosaic datasets are a powerful way to store, manage and utilize large amounts of raster data. They also provide the user with additional functionality through the use of functions. These functions allow the user to apply “on-the-fly” operations that alter the mosaic datasets; these functions can be applied to the dataset as a whole or to individual rasters contained within the mosaic dataset.
How to apply the pansharpening function:
1. In ArcMap, right click on the mosaic dataset in the Catalog and select “Properties.”
2. Navigate to the “Functions” tab at the top of the window.
3. Right click on the “Mosaic Function” under the Function Chain and select “Insert,” and then
select the “Pansharpening Function.”
4. In the dialog box that appears, first select the “Pan Sharpen” tab, and then navigate to the
panchromatic mosaic dataset. Leave the multispectral box as is, and delete the text from the
infrared box. Check the box below to “use the fourth band of the multispectral image as the
5. In the “Properties” section:
a. Choose the appropriate method (in this case Gram-Schmidt was used).
b. Choose the sensor type (in this case Quickbird).
c. Leave the rest default (these options should automatically populate to correspond with
the sensor type chosen).
6. Click “OK” to exit the function. The function chain should now appear like the image below.
Because functions apply from the bottom up, the “Pansharpening Function” is located above
the “Mosaic Function.”
7. Click “Apply,” then “OK” to apply the pansharpening to the mosaic dataset.
This blog posting was developed with the support of a competitive grant (cooperative agreement number P09AC00212; task agreement number P13AC00875) from the National Park Service in partnership with the North Atlantic Coast Cooperative Ecosystems Studies Unit. It is part of a larger document available for download on the IRMA Portal.