The only tool that I know to do what you want is Medial Axis. There was many discussion on this forum on this technique. I doubt it will work here. The tool you need is Rooster/Potrace with an option that I don’t know if it exists. You need something with curve with variable thickness.
We had a discussion of Potrace, so you could surely have more options.
It seems that there are some other tools
I tested a bit Vextractor that has some ability to extract median curve.
traditional graphic.3dm (614.3 KB)
