Update

Added an algorithm which will ignore lonely/corrupt chunks, and therefore regions with no chunks. This may or may not reduce the image size.

This addition is quite slow. The bigger the map, the even slower the processing. There may be a solution where one could run a faster algorithm on each region instead, but that could result in edges of a map to disappear, as a region could have small chunks on its edges.

Edit: Added that as well, but even though it is significantly faster, there is a slight chance that chunks between regions may not be found. This is rare and should not pose a big problem, but worth noting if edges on a map disappears.