As mentioned yesterday I am now working on new maps of Cromwell and hope to get some coverage that will also give me the valley going to the top of Lake Dunstan in conjunction with the Cromwell Museum to have full coverage of the historical appearance of that area.
After some experimentation I am doing new mosaics with much larger geojpeg tiles for Qgis because the new imagery is of such a high resolution that scaling it down to fit the old mosaic tiles lost far too much detail. This entails getting the highest resolution tiles available from Linz Data Service and scaling them up so there is more of a match in size for the Retrolens stuff to drastically reduce the scale down and loss of quality on the latter.
This will be for Cromwell station and Clyde station only. I am not redoing the gorge which would take much too long, instead I will use the existing Gorge stuff that I have as it does not need to be at a higher resolution as there is not much detail on the ground.
The mosaic so far is looking extremely good with the quality of Cromwell Station being very high, almost as good as what was in the previous post, and it means maps will be able to be of much higher quality for that yard. The same approach will be followed for other yards that I have this high quality NZR survey imagery for. These include:
- Clyde - both 1st and 2nd stations
- Alexandra - in addition to the early 1980s NZR survey an older one from the early 1970s has turned up.
- Omakau
- Ranfurly
- Waipiata
- Middlemarch
I expect to finish the Cromwell mosaic today and probably start the Clyde one tomorrow, then redrawing the maps will be quite fast so this is not going to slow things down much.
