[Talk-us] Poor JOSM Yahoo imagery solution?
Frederik Ramm
frederik at remote.org
Tue Nov 24 03:20:44 GMT 2009
Alan,
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.
Bye
Frederik
--
Frederik Ramm ## eMail frederik at remote.org ## N49°00'09" E008°23'33"
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