So the masking is now more or less complete having taken somewhat longer than expected, although mostly this is due to other reasons other than the masking itself. I just have to recheck and then I can put out the geojpegs for Qgis. Which is now 2.18 for working on all my maps - no more development masters except to the extent I need to go back to 2.18.
I have looked at what historical aerial imagery exists for Dunedin and it does go back to the 1940s, so we just have to wait until all the historical stuff has been scanned for Otago and it will be possible to do this with preferably 1960s images.
