How to Georeference an Image (Raster data) on QGIS
In this tutorial, I demonstrate how to georeference an old map in QGIS using a historical Nairobi 1993 street address map overlaid onto an OpenStreetMap base map.
Step- by- step description.
Adding a base map to QGIS workspace, loading a raster image, selecting accurate ground control points (GCPs), choosing the correct transformation method, and generating a properly aligned georeferenced image. By comparing the old map with current data, we can visually analyze how Nairobi has changed over time.
What to learn in this video:
How to add base maps in QGIS using QuickMapServices
How to load and georeference a raster image
How to select reliable ground control points
Understanding linear, Helmert, and polynomial transformations
How to export a georeferenced map correctly
Comparing historical and modern spatial data in QGIS
Software used: QGIS
Data source: Historical Nairobi map (1993) + OpenStreetMap