[OSM-talk] Projections

[Nick Black]

The tiling is done by generate_tiles.py - which uses a google projection.

On 1/19/07, Christopher Schmidt <crschmidt at metacarta.com> wrote:
> On Fri, Jan 19, 2007 at 03:37:19PM +0000, SteveC wrote:
> > * @ 19/01/07 03:30:15 PM andrew.rowbottom at gmail.com wrote:
> > > >Are you trying to say that there is a standard for tiling in Mercator
> > > >projection written down somewhere, and we are breaking it?
> > >
> > > The big issue here is that the program used to display the tiles must
> > > know the projection used if it wants to convert pixel coordinates (or
> > > tile names) to lat/long. The current implementation assumes a
> > > particular conversion that is not the same for all the different sets
> > > of tiles.
> >
> > The current (top two layers) tiles can be dropped in to google maps -
> > it's a pretty compelling reason to stick with it.
>
> Unless you're using a different definition than I am, I don't think
> that's true... maybe I'm misunderstanding something though. Google, in
> my experience, uses a simple mercator projection, and OSM isn't creating
> tiles that match that...
>
> Regards,
> --
> Christopher Schmidt
> MetaCarta
>
> _______________________________________________
> talk mailing list
> talk at openstreetmap.org
> http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
>


-- 
Nick Black
--------------------------------
http://www.blacksworld.net