Converting a colour map into an outline?
I GM in the Hyborean age. We're currently using this map:
I've printed it out but I have a problem recording the party's travels on it. If I print it out in either B&W or colour, then I have a hard time making legible marks on it - practically everything is hard to see against the background.
My best solution so far is a silver gel pen, but even that's tricky. I tried to trace it, but there's a good deal of detail I'd like to retain - basically I'd like to discard the coloured gradiants and render it as a simple "outline map", like this: Example
Retaining the city names and whatnot would be nice, but secondary.
Is there a photoshop script or some other tool I could use? Ideally I'd prefer having to hand draw (trace) or commission someone (the map doesn't belong to me, I do not think it would be right to pay someone to copy it) unless I really have to.