The JPG one is the full map, the PNG is selective crop.
Here's a quarter-sized one which shows it.
(Wondering if there's some way to identify warp points and do full-sized map image for just those local parts of the map which can be overlaid on a much smaller map and then display when hovered over. Possibly makes sense to wait for that bukket thing.)
EDITED: 6 Feb 2011 22:11 by BOUGHTONP