[gdal-dev] Problem with GDAL data folder in 1.9

Frank Warmerdam warmerdam at pobox.com
Tue Apr 10 16:53:34 EDT 2012


On Tue, Apr 10, 2012 at 1:41 PM, Ivan Lucena <ivan.lucena at pmldnet.com> wrote:
> It seems to me that the GTIFF driver tries to interprets the WKT instead of just pass it on. Is that right? It doesn't seems to be doing it right.

Ivan,

When the GeoTIFF file contains parameters in addition to the PCS code,
it is likely that the coordinate system is being composed from the
parameters instead of being derived from the PCS code.  Basically the
geotiff file is overspecified and the driver makes a choice not to
trust the PCS code.  For instance, sometimes folks change the linear
units and trusting the PCS code would lead to wrong results.

The final coordinate system seems correct if a bit different in
details (like PCS name) from what you might expect.

Ideally we would compare all the parameters to the ones from the PCS
and if everything matches we would actually use the PCS code and
attach it as an authority code.   So if you file a ticket on this issue that
would be the features I'd hope to implement.  That might be a bit hard
though.

Best regards,
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Software Developer


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