How turn a map black and white
I'm new to software-based mapmaking and I was wondering if there was an easier way to get the map attached below into full black and white(so white land and completely black sea - no blue outline). The reason is because I want to try out Tear's Sideran-style tutorial ( http://www.cartographersguild.com/sh...hlight=Saderan ). I have access to GIMP and Photoshop. The map itself exists as a single layer image.
Edit: and I've accidentally posted in the wrong forum. Sorry about that!