[Gdal-dev] Trouble reading Geotiff projection

[Frank Warmerdam]

CELLIER François wrote:
> Hi everybody,
> 
>  
> 
> I need to read geotiff with the gdal library. This geotif had no 
> projection so I opened it through Global Mapper and Export it in order 
> to have a projection within it. When I do a gdalinfo on the file I have :
> 
>  
> 
> Driver: GTiff/GeoTIFF
> 
> Files: testAvecProj.tif
> 
> Size is 4000, 4000
> 
> Coordinate System is:
> 
> PROJCS["NTF (Paris) / France II",
...
> 
> GDALAllRegister();
> 
> this->_pGDALDataSet = (GDALDataset *) GDALOpen( 
> _NomFichierImport.c_str(), GA_ReadOnly );
> 
>  
> 
> In debug mode, the pszProjection field of _pGDALDataSet is :
> 
> PROJCS[“unamed”,GEOGCS[“unamed”,DATUM[“unknown”,SPHEROID[“unretrievable’ 
> etc…
> 
>  
> 
> Can someone tell me what I did wrong ?

François,

To get names like "NTF (Paris) / France II" for the coordinate system
strings from a GeoTIFF GDAL needs to lookup the geotiff codes in the
support files pcs.csv and gcs.csv normally living in gdal/data, and
installed in locations like /usr/local/share/gdal.

If they are not found you will get things like "unnamed".  You may
find you need to set the GDAL_DATA environment variable to point to
the directory where these data files are found.

Best regards,

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