Loading a raster layer
The QGSRasterLayer
API provides a convenient, high-level interface to raster data. To use this interface, we must load a layer into QGIS. The API allows you to work with a layer without adding it to the map. In this way, we'll load a layer and then add it to the map.
Getting ready
As with the other recipes in this book, you need to create a directory called qgis_data
in our root or user directory, which provides a short path name without spaces. This setup will help prevent any frustrating errors that result from path-related issues on a given system. In this recipe, and the others, we'll use a Landsat satellite image of the Mississippi Gulf Coast, which you can download from https://github.com/GeospatialPython/Learn/raw/master/SatImage.zip.
Unzip the SatImage.tif
and SatImage.tfw
 files and place them in a directory named rasters
within your qgis_data
directory.
How to do it...
Now we'll go through how to load a raster layer and then add it step by...