2009/11/24 Frederik Ramm <[email protected]>: > Alan Mintz wrote: >> Is anyone working on a solution to the poor Yahoo image quality in JOSM >> (compared with Potlatch, browser, etc.)? This pic shows the striking diff >> between the same area at the same scale in JOSM and in Potlatch: >> http://sites.google.com/site/am909geo/osm-1/BadYahooImagery.jpg?attredirects=0 > > Interesting. When I call up this area in JOSM, or indeed using any > standard "Yahoo Map API" example, the image URLs that are retrieved look > like this: > > http://maps1.yimg.com/ae/ximg?v=1.9&t=a&s=256&x=22784&y=13251&z=1 > > That's the best zoom it gives you (z=1, smaller being better). So JOSM > plays according to the rules of the Javascript API. However using > Potlatch, which presumably uses a Flash API, the map tiles requested > look like this: > > http://us.maps3.yimg.com//aerial.maps.yimg.com/img?md=1204827325&x=45569&y=26502&z=19&r=1&v=1.7&t=a > > and have a better resolution - z=19, higher being better in this scheme. > > The key to fixing this in JOSM would be finding a way to get the > high-res imagery through the Javascript interface. So if anyone would > manage to modify any of the examples on > > http://developer.yahoo.com/maps/ajax/ > > to actually give you the high-res image then we could use that knowledge > to improve JOSM. (I'm cc'ing this to the JOSM-dev list.) - We are not > allowed to cheat our way out of the Javascript API, sadly, which means > we cannot retrieve the tiles directly even if we knew how to.
I have heard on IRC that Potlatch bends the API slightly to get these images. However, the only area Yahoo has better resolution than z=1 is the US where the imager comes from another source (calles USGS I think) that can be used as a WMS directly so there's little gain from being able to get it through Yahoo. Regards _______________________________________________ josm-dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/josm-dev
