[OSM-dev] OSM over Yahoo! Satellite

Christopher Schmidt crschmidt at metacarta.com
Thu Oct 25 13:56:06 BST 2007

On Thu, Oct 25, 2007 at 12:57:03PM +0100, Robert (Jamie) Munro wrote:
> Christopher Schmidt wrote:
> > http://labs.metacarta.com/osm/over-yahoo/
> > 
> > Opacity slider, and three layers -- the base mapnik layer, the one I
> > maintain, and hte t at h layer. (The one I maintain makes no statements
> > or gaurentes it will work -- I just like being able to see it when it is
> > working.)
> Cool!
> Can we get mapnik to render PNGs with a transparent background (but
> using the alpha channel for anti-aliasing, rather than a white
> background, and just set the page background to be white?

That's a question for someone other than me. I have no experience with
Mapnik tobe sure.

> > The opacity slider will adjust the opacity for the three overlays, so
> > you can see through to the map.
> > 
> > Uses YUI for the slider.
> > 
> > (I'm assuming that this is acceptable to OSM, since there is not a
> > problem with abusing Yahoo!'s satellite tiles for OSM purposes the way
> > there might be for map tiles or something similar.)
> The issue with Yahoo is you have to use their official APIs, not write
> your own code to download their image tiles directly. 

Correct. This is what the demo in question is doing.

> It's true that
> their terms and conditions do not prevent us from deriving data from the
> imagery, but only as long as we access the tiles through their official
> APIs. 

I'm not sure if this is directed as a criticism of this particular map,
or just a general comment. 

Christopher Schmidt

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