I took a picture of a patch, and have been cleaning it up for use in a router (I will be engraving it) and I can't seem to figure out how to get inkscape to produce single line paths from my image. It keeps detecting the inner and outer edges (the lines are sort of thick) when I really need just the one line down the center of everything. I don't want to engrave it as double lines since it will take longer and I don't like the look of the dual line.
I have exhausted my own googling, youtube tutorials, and trial and error, so I have come here for guidance. Attached are my source and the dual line that I don't like. I am trying to get it this into dxf for import into my other program and any help will be much appreciated!!
Source:

Ugly dual line:
