Georeferencing a Scanned Topographic Map using QGIS

In this video, you will learn how to use the Georeferencer tool of QGIS to assign the correct geographic information to a scanned topographic map.

Georeferencing is the process of defining the existence of a certain geographic object in physical space by assigning the actual coordinate properties to the object, considering a specific coordinate reference system.

Typically objects like aerial photos or scanners maps, when found in file formats such as JPEG, PNG, do not contain any geospatial properties in them. This means, if you were to drag the image and drop it in a GIS software like QGIS or ArcGIS, it would not be placed where its supposed to be due to the fact that no specific coordinate values have been assigned for any of the pixels of the image.

Therefore, the process of taking a raw image and transforming it into an image which consists of the aforementioned geospatial properties is the core technique that is discussed in this tutorial. As the raw image, a scanned topographic map was used for the purposes of this tutorial as it originally did not contain any coordinate reference properties.

You may also check out the following videos that are related to this tutorial:

#georeferencing #qgis #geodeltalabs

[praiseborngreat]

Your lectures are clear and explanatory. Thank you for all you do.

[PrasadPLVK]

I love your way of explanation and your vocabulary

[Official-gegc]

Thank you so much for this interesting and significance video!

[MrABN]

Thanks for the information, if any auto processing is there?

[isaacnzayisenga]

Wonderful Lecturer, you're important to me.
In the coming videos if possible, you can help us how to records spatial data of an area using GPS and how to enter those data in ArcGIS for making a map of that area.
Thanks in advance for your time and support to us.

Isaac Shepherd
Kigali-Rwanda

[JackyVSO]

Thanks for the tutorial! When I try this on a different map from the same source, the topographical map is consistently about 0, 1 km too far North. What could be possible reasons for this? I entered 9 mostly evenly spaced points by zooming and clicking on the grid on the map.

[ananyag]

In the georeferencer window, the Mean Error shows 2.59.. What does this mean? is it in meters or feet?

[praiseborngreat]

If I decide to import a shape with a different CRS, do I need to transform the new shapefile to the current CRS?

[tubuobaggio]

Is it possible to teach us the basics in creating geoprocessing tools using python (Jupiter Notebook), that will be very helpful
thanks very much

[azeemsyed]

Hi sir thank you so much, i learnt lot from your videos
Sir i have dout please Help me.., how georeference a kml and DWG files in qgis rather than png and jpg files
How to Align in qgis as we do in autocadd

[wlgypxl]

The topo map of Nicosia for example are like two maps combined together, so I think this technique cannot be used.
Also in Tactical Pilotage maps there are problems in their georeference.

[Parcha]

how to get lat, long coordinates corresponding to the image map