[Gdal-dev] Warping Plate Carree images to Mercator

[Lennox Antoine]

I believe this is the same projection used in VirtualEarth
(http://local.live.com/default.aspx?v=2&cp=0~0&style=h&lvl=1&scene=1875974),
so you can check out the projection they used to get it into
Geographic LL coordinates.

http://www.brains-n-brawn.com/default.aspx?vDir=veworldwind

I'll paste the reprojection area of the code here :

//NOTE tiles did not line up properly with ellps=WGS84
//string [] projectionParameters = new string[]{"proj=merc",
"ellps=WGS84", "no.defs"};
//+proj=longlat +ellps=sphere +a=6370997.0 +es=0.0
string [] projectionParameters = new string[]{"proj=merc",
"ellps=sphere", "a=" + earthRadius.ToString(), "es=0.0", "no.defs"};
proj = new Projection(projectionParameters);

I have also had luck estimating it with tangent and log functions
without using proj.4.

-Lennox


On 6/1/06, Joaquim Luis <jluis at ualg.pt> wrote:
> I don't know what is the projection of  the Google image. Maybe a Miller
> cylindrical.
> I don't know either the proj string to do it.
> You can look at the GMT cookbook to see many example maps of different
> projections.
> (the site seams to be having some problems right now)
>
> Joaquim
> >
> > Ah, thank you!  That helps, but I still can't figure it out.
> >
> > Basically what I'm trying to do is convert this:
> >
> > http://veimages.gsfc.nasa.gov/7107/world.topo.bathy.200408.3x5400x2700.jpg
> > <http://veimages.gsfc.nasa.gov/7107/world.topo.bathy.200408.3x5400x2700.jpg>
> >
> > Into something that looks like this:
> >
> > http://maps.google.com/?ll=4.915833,56.25&spn=179.778788,360&t=k&om=1
> > <http://maps.google.com/?ll=4.915833,56.25&spn=179.778788,360&t=k&om=1>
> >
>
> _______________________________________________
> Gdal-dev mailing list
> Gdal-dev at lists.maptools.org
> http://lists.maptools.org/mailman/listinfo/gdal-dev
>