I am trying to scale a JPEG image based on the grid present in the image.

I know each tick in the image shows 10km, and I want to display circles of 4.5km in diameter over this image. I can't figure out how to scale the image so each tick IS 10km in QGIS, so I can represent the circles properly. Is there some sort of tool that will allow me to pick two points, and say they are 10km apart?

I don't think georeferencing is a solution as I don't have any geolocation info.

  • Georeferencing is the way to go. If you don't have "geolocation info", you should add it, e.g. using the grid values. There are a lot of tutorials out there that show you how to do it. Once georeferenced, create buffers in QGIS, see here: gis.stackexchange.com/a/438809/88814
    – Babel
    Sep 5, 2022 at 13:55


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