Creating raster footprints

A common way to catalog raster datasets that consist of a large number of files is by creating a vector dataset with polygon footprints of the extent of each raster file. The vector footprint files can be easily loaded in QGIS or served over the Web. This recipe demonstrates a method to create a footprint vector from a directory full of raster files. We will build this program as a Processing Toolbox script, which is easier to build than a QGIS plugin and provides both a GUI and a clean programming API.

Getting ready

Download the sample raster image scenes from https://geospatialpython.googlecode.com/svn/scenes.zip. Unzip the scenes directory into a directory named rasters in your qgis_data directory.

For this recipe, we will create a new Processing Toolbox script using the following steps:

1. In the QGIS Processing Toolbox, expand the Scripts tree menu.
2. Next, expand the Tools tree menu.
3. Finally, double-click on the Create new script item to bring up the processing script...