Since our last tutorial regarding georeferencing images in QGIS is 4 years old, let us have a second look at this task in the current times of QGIS 2.16. For this tutorial we will use a Soviet map of Crewe in England to see changes in city structure with a snapshot from 1957. We will use simple and quite easy affine transformations for this purpose.
In my first GIS-course I was presented with the concept of quality measures for a georeferenciation. My lecturer taught me: “There it is: the RMSE or root mean square error. Keep in mind: it should be not bigger than half the pixel size!” That was all I got. If you facing comparable words stick with us!