Greetings everyone,
It has been quite a while since I was last on here. I have a question, though, for the GIMP minded of us.

How does one take a finished map and extract the outline of the coasts for an overlay?

A bit of background as to why I ask. I recently lost all my GIMP files in a computer crash. A terrible tragedy. Thankfully, I had saved my finished maps off on to an external drive but not the GIMP files which contained all the layer information. I only have the .JPG files I exported from GIMP. My next project was to be a political overlay for the various countries to show how the land was divided up amongst the country's ruling families. I could hand draw the coastlines but the result would be far sloppier than I would like. It would be best if I could somehow copy only the outline of the continents to a new layer so that I might use them in my overlay.

Thank you all for your time.

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