Given a set of tiles covering a large area at a particular zoom level (These are online on someone's tile server and will need scraping, but let's assume these are on disk if it's easier. With TMS ...
Normally I would create an Image Pyramid using gdal_retile.py on one large image or a set of large images. I want to do the opposite. I have all the zoomed in tiles on the base level and I want to ...