[OSM-dev] OSM over Yahoo! Satellite

Dave Stubbs osm.list at randomjunk.co.uk
Thu Oct 25 15:34:33 BST 2007


On 25/10/2007, Christopher Schmidt <crschmidt at metacarta.com> wrote:
> 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.

It's possible -- but you'd need to create a different tile set.
Basically you just edit the style file to remove the background
colour, and then don't let it draw in the coast polygons and possibly
world boundaries. That would normally suck, but as we have the aerial
underlay, it's actually what we probably want.

I've done a bit of the cycle layer like this here: (adsl, so maybe
slow, and also a limited number of tiles)
http://beerwarmer.randomjunk.co.uk/yahoo-cycle/

Obviously it would need more work if I was doing this for real -- the
parks are awful.




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