The problem is that we make tiles for each map individually and then older ones just override earlier ones. We really want to make vrts for maps which overlap which will make much nicer looking tiles.
Work out the extent of each image.
Group images together which overlap (finding the islands). Make a VRT for each island (note that an island can have just 1 image in it).
Make tiles for each of these VRTs
I am unsure how to efficiently achieve point 2 currently.
The problem is that we make tiles for each map individually and then older ones just override earlier ones. We really want to make vrts for maps which overlap which will make much nicer looking tiles.
I am unsure how to efficiently achieve point 2 currently.