Rasterizing a vector layer

Sometimes, a raster dataset is a more efficient way to display a complex vector that is merely a backdrop in a map. In these cases, you can rasterize a vector layer to turn it into an image.

Getting ready

We will demonstrate rasterizing a vector layer using the following contour shapefile, which you can download:

https://github.com/GeospatialPython/Learn/raw/master/contour.zip

Extract it to your /qgis_data/rasters directory.

How to do it...

We will run the gdalogr:rasterize algorithm to convert this vector data to a raster:

1. Start QGIS.

2. From the Plugins menu, select Python Console.

3. Import the processing module:

           import processing 
   

4. Run the algorithm, specifying the input data, the attribute from which to draw raster values, 0 to specify the pixel dimensions for the output instead of map dimensions, then the width and height, and finally the output raster name:

           processing.runalg("gdalogr:rasterize",
                             "/qgis_data/rasters/contour...