Coloring a map, one color per country

Question

How could one use the Gimp to easily transform a map with many colors into a map where each country is fully colored in a single unique color. I used the Color > Threshold option to get a b&w image, then filled the country-borders with more black pixels where they were missing, and erased the black pixels inside a country's territory, before using the fill tool to fill each country with its own color.

That's very tedious and long work, and probably someone has a better idea, which they'll be happy to share with me ;)

Answer 1

I may be misunderstanding your question, but I don't imagine there is a simple way for GIMP (or any other graphics program) to discern and color arbitrary regions on an image with a unique color. How would it know things like Great Britain or United States having multiple geographically-separated regions but color them the same?

You'd better buckle down and getting ready for some tedium...