[Proj] Problem overlaying georeferenced images in Google, Maps(projection problem!)

Jorge jorge.arevalo at gmail.com
Mon Jun 2 04:23:39 EDT 2008

Hi everybody

To Janne and Cliff:

> Hmmm....
> are you sure the "gdalwarp" you are using uses the latest proj-4 libraries?
> Are you sure all programs are doing what thye should? If so, it is maybe the
> input data (assumptions) then?
The gdal tools and the proj.4 libs are the last version, yes. And I'm using them in the way the instructions say, I think. But is
obvious that I have a mistake. Maybe there is an error converting the MIF/MID files in a raster file, but the process is so
simple... I will review it, anyway.

> More ideas...
> The huge north shift, which is visible in your pictures,  is usually due
> to the conversion between spherical and elliptical. There is a way to
> go around that, but how it should be done in your case.... ???

> I believe the easiest solution to that would be to correct that north shift by utilizing Rectifying Latitude for the 
> International ellipsoid at the center of the area.  Don't know if that's in the PROJ4 Toolkit, though ...

Mmm... thanks for the clue! Then, I should do this for every province's files (52, exactly), but maybe the shift isn't the same 
in all... I'm going to see the rest

To Jose:

The "before" shift isn't the same as mine, but this is VERY interesting... What projection is "before" and what is "after", What 
are the input data? How did you do??

Thanks a lot!



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