How to extend an OSM or raster area in QGIS (into 'No Data' area)?

Question

I need to do the opposite of clipping down a raster (or SHP file) in QGIS (or Gdal, Python etc - even R if someone can provide the script).

I have a dataset from Open StreetMap (*.OSM) which includes the south west corner of a country. I have also converted this to a SHP file or Raster format).

To match with my other Maxent datasets I need to expand the OSM data south and west so I am only increasing the 'no data' areas at the left and bottom of the files.

I have looked at previous questions but not found a clear answer for this. Is there a way to do this in QGIS?

Answer 1

This process worked for me:

http://ssrebelious.blogspot.co.uk/2012/09/raster-extent-modification-using-qgis.html

"In QGIS you can change extent of the rasters. Lets examine one of the worst case scenarios. There are two overlapping (one band) rasters A and B. Say, we need to add A values to B values and get the final image to have extent that will contain both images."