How to Pan-sharpen Images

Introduction

In this article, you will learn how to pan-sharpen geospatial datasets that you previously purchased either through the UP42 data platform (collections, catalog or tasking orders) or the UP42 processing platform (data blocks).

Pan-sharpening is a remote sensing algorithm that uses a higher-resolution panchromatic image to fuse with the lower-resolution multiband image. This outputs a multiband image with the spatial resolution of the panchromatic image.

This transformation is widely used, because geospatial data producers frequently provide low-resolution multiband images and higher-resolution panchromatic images of the same scene. Increasing the spatial resolution with the help of pan-sharpening provides a better visualization of the multiband image.

Currently, you can apply pan-sharpening directly on the UP42 platform or in third-party GIS software. In this guide, the following pan-sharpening tools are described: the processing block Pansharpening and the function GDAL Pansharpening available in the free software QGIS.

Pan-sharpen with UP42

Requirements

In this section, you will learn how to apply pan-sharpening on geospatial datasets. This algorithm will be applied using the UP42 processing block Pan-sharpening. This processing block is compatible with the following satellite images: Pléiades, SPOT 6/7 and Sentinel-2. The compatible data blocks are shown in the table below.

Steps

In order to apply pan-sharpening on the UP42 platform, please follow the steps below:

1. Create a new workflow by adding one of the compatible data blocks and then add the processing block Pan-sharpening.

2. Click Save & Configure Job.

3. In the job configuration window, find the parameter method and select the preferred pan-sharpening method: Brovey, Esri or SFIM.

4. Select the job type Live Job and click on Run Job.

5. You are redirected to the dashboard of your job that is currently running. Wait until the job run is successful.

6. Download the pan-sharpened image output.

7. Render the pan-sharpened image output in a third-party GIS software. For more information, please refer to Visualize the Outputs.

Example

A workflow that contains the data block Pléiades Reflectance (Download) and the processing block Pan-sharpening:

Pan-sharpen with QGIS

Requirements

In this section, you will learn how to apply pan-sharpening using the function GDAL Pansharpening available in the free software QGIS.

Steps

In order to apply pan-sharpening in QGIS, please follow the steps below:

1. a) If you have geospatial datasets already delivered to Storage through job runs or data ordering (collections, catalog or tasking orders), go to Storage and download the assets locally.

   b) If you do not have geospatial datasets delivered to Storage, then follow the steps from the previous section Pan-sharpen with UP42.

2. Open QGIS.

3. Create a new project.

4. Drag and drop the multispectral band and the panchromatic band.

5. Go to the tab Processing > Toolbox. A toolbox panel appears on the right side.

6. Type in Pansharpening and click on the function provided by GDAL.

7. A new window appears. Select the correct images for both the spectral and the panchromatic datasets. For Pléiades and SPOT 6/7 satellite images, the filenames usually indicate the image type (MS for multispectral and P for panchromatic).

8. Click on Run.

9. The pan-sharpened image will automatically be displayed as a new layer in your QGIS project.