Well, you won't be doing it from an image straight from VGMaps.com. These image formats (.PNG mostly, but also .GIF and .JPG) definitely just keep what you see, there's not going to be any "history" that you can dig through. All you can really do is crop out a section that matches the resolution of the screen (like a 256 x 224 chunk out of a NES or Super NES map, for instance - which obviously won't have any HUD stuff). Unless you want to go to the trouble of contacting the mapper and requesting their work files.