Scaling an imported image to fit a known length.

I have been looking for this information but not found it here. If the question is already answered point me there and I will delete this post.

I am used to AutoCAD but am now moving to free versions. I was using FreeCAD for a while, but did not need the 3D-funtions so moved to LibreCAD.

In FreeCAD it was possible to import an image, and then scale it so that a known length got that actual length. I want to do this in LibreCAD to, but find no way to do it.

Say you have a paper map. You scan it, and then import it. There is a line on the bottom of the map with a scale. Thus you know that one specific line on the map is 10 meters. However if you draw a line along that line it will be 369.94256 mm. I want to reset the scale of the whole picuture so that the line is 10 000 mm when I am done.

There is a dead simple way to do this in FreeCAD. This tutorial show how to do it inf FreeCAD and will ilustrate what I want to do: (Timestamp 04:00)

https://www.youtube.com/watch?v=fJQvFsGXz-c&list=PLWuyJLVUNtc0UszswD0oD5q4VeWTrK7JC&index=4

How is the same thing done in LibreCAD?

https://wiki.librecad.org/index.php?title=Measure_Areas

For the scale option,

You can select a center, and a number or a pair of number to do anisotropic scaling.