[Gdal-dev] Trouble reading Geotiff projection

[CELLIER François]

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",

    GEOGCS["NTF (Paris)",

        DATUM["Nouvelle_Triangulation_Francaise_Paris",

            SPHEROID["Clarke 1880 (IGN)",6378249.2,293.4660212936265,

                AUTHORITY["EPSG","7011"]],

            AUTHORITY["EPSG","6807"]],

        PRIMEM["Paris",2.33722917],

        UNIT["degree",0.0174532925199433],

        AUTHORITY["EPSG","4807"]],

    PROJECTION["Lambert_Conformal_Conic_1SP"],

    PARAMETER["latitude_of_origin",46.8],

    PARAMETER["central_meridian",0],

    PARAMETER["scale_factor",0.99987742],

    PARAMETER["false_easting",600000],

    PARAMETER["false_northing",2200000],

    UNIT["metre",1,

        AUTHORITY["EPSG","9001"]],

    AUTHORITY["EPSG","27582"]]

Origin = (601499.999999999420000,2428999.999999997700000)

Pixel Size = (0.125000000000000,-0.125000000000000)

Metadata:

  AREA_OR_POINT=Area

Image Structure Metadata:

  COMPRESSION=PACKBITS

  INTERLEAVE=BAND

Corner Coordinates:

Upper Left  (  601500.000, 2429000.000) (  0d 1'13.55"E, 48d51'33.85"N)

Lower Left  (  601500.000, 2428500.000) (  0d 1'13.54"E, 48d51'17.67"N)

Upper Right (  602000.000, 2429000.000) (  0d 1'38.07"E, 48d51'33.84"N)

Lower Right (  602000.000, 2428500.000) (  0d 1'38.06"E, 48d51'17.66"N)

Center      (  601750.000, 2428750.000) (  0d 1'25.80"E, 48d51'25.75"N)

Band 1 Block=4000x1 Type=Byte, ColorInterp=Palette

  Color Table (RGB with 256 entries)

    0: 31,45,31,255

    1: 30,52,40,255

    2: 41,50,29,255

    3: 39,46,35,255

    4: 44,57,42,255

 

 

To read it I started from the example of the gdal website :
http://www.gdal.org/gdal_tutorial.html

 

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 ?

 

 

Best regards,

François 

 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/gdal-dev/attachments/20081008/c9c64c2a/attachment.html