Sorry for being vague, I don't do this often...

Something something.. path...
trace bitmap tool...

Which is probably covered in your links.

Anyway...
You'll likely have to play with whatever levels and clean up manually.
Level filters can be used on individual color channels if I remember right.
Beware the tool not liking super sharp angles too much. Finding the sweet spot between too much smoothing and too much noise is sometimes annoying.
Compression artifacts can cause noise in the path, the cleaner the source the better.

I don't remember the menu, but you can also edit individual points in the generated path if needed.

Anyway, that's what I do to transform a picture into a 2D path to later import in 3D CAD software.