Thanks to Paul Norman's efforts and visualizations based on it[1], there has been a lot of activity in remapping coastlines lately and a lot of improvement. However one loophole that Paul's method does not detect is islands that will have their coastlines vanish completely. I decided to take a look at this tonight. So far I have come up with a pretty hackish way of looking at things... but I think it might still be of use.
I downloaded all natural=coastline ways from my jxapi. Then I split the world into 4 parts to make them small enough for me to open in JOSM. Then I selected all objects that were last touched by an accepting user and purged them from the data set. What is left is all ways that were last touched by a decliner. Some of these are actually OK from a license standpoint. Maybe the decliner just deleted a tag or added some nodes in the middle of a way which will obviously distort the geometry but the coastline topology will remain intact so they don't show up in Paul's files. Also, some things that I purged may still be heavily impacted or even completely removed by the license change if they were created by a decliner but last touched by someone else. So it isn't perfect. The south/west quadrant of the world is actually pretty much good to go. I already fixed a few islands. The north/west one is still a little large so I may have to do some more tinkering there. The one I have ready to go right now is south/east (Australia) and I saw this topic come up in the talk-au archives a few days ago so I thought I would go ahead and share. Perhaps someone who is subscribed to talk-au can forward this? What I have is a ~10MB .osm file containing 537 ways (plus some stray nodes that should just be ignored): http://ni.kwsn.net/~toby/OSM/coastline_SE_bad.osm.gz This file covers from the equator to the south pole and from 0 to 180 longitude so it is more than Just Australia although that is the most impacted area. The way to use this would be to download it and open it in JOSM. Then do a "type:way" search and run the license plugin on that. Then just look for the big red blobs. DO NOT use this layer to edit and upload or terrible things are likely to happen. Use it only as a guide to find trouble spots. I set the upload=false flag in the file so JOSM should be very clear about this if you try to upload from this layer. So download a problem area to a new layer and replace dirty coastlines to your heart's content. The biggest blob of red is on the northeast side of Australia. Some of them are random rocks along the coastline that cover a few square meters. Some are large islands. Unfortunately it looks like Bing isn't good enough to retrace some of these but I'm hoping the locals may have other sources. Enjoy, Toby [1] http://www.wightpaths.co.uk/coast/CT-only.php _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
