[gdal-dev] GDAL C# bindings and TIFF read projection trouble

[Tamas Szekeres]

Hi,

Here is a similar code what gdalinfo is doing right now, and you
should get the same results with that:

Dataset ds = Gdal.Open(infile, Access.GA_ReadOnly);
  // get the projection
 string proj = ds.GetProjection();

SpatialReference sr = new SpatialReference(proj);
string prettywkt;
sr.ExportToPrettyWkt(out prettywkt, 0);

Console.WriteLine(prettywkt);

Best regards,

Tamas



2008/4/1, Kerry Halligan <halligan.kerry at gmail.com>:
> Can anyone help me out with problems reading the correct projection
> information from a TIFF image?
>
> I am using GDAL C# bindings from FWTools (1.3.9) and am getting unexpected
> results for projection information of TIFF files.  If I use the gdalinfo
> utility I get the correct information, but if I use the gdal_csharp bindings
> I get "unnamed" as the projection.  This is causing difficulty when
> comparing projections before processing multiple files.  I am assuming this
> is a data and/or operator error, rather than a bug, but can anyone tell me
> what I might be doing wrong?  I also tried this with the most recent version
> of FWTools and received the same results.
>
> Sample outputs are listed below:
>
> gdalinfo results:
>
> C:\Program Files\FWTools1.3.9>gdalinfo
> E:\Imagery\ortho\drcog\3130375_1610645.tif
> Driver: GTiff/GeoTIFF
> Files: E:\Imagery\ortho\drcog\3130375_1610645.tif
>  Size is 5000, 5000
> Coordinate System is:
> PROJCS["NAD83 / Colorado Central",
>     GEOGCS["NAD83",
>         DATUM["North_American_Datum_1983",
>             SPHEROID["GRS 1980",6378137,298.2572221010002,
>                  AUTHORITY["EPSG","7019"]],
>             AUTHORITY["EPSG","6269"]],
>         PRIMEM["Greenwich",0],
>         UNIT["degree",0.0174532925199433],
>          AUTHORITY["EPSG","4269"]],
>     PROJECTION["Lambert_Conformal_Conic_2SP"],
>     PARAMETER["standard_parallel_1",39.75],
>     PARAMETER["standard_parallel_2",38.45],
>      PARAMETER["latitude_of_origin",37.83333333333334],
>     PARAMETER["central_meridian",-105.5],
>     PARAMETER["false_easting",3000000.000316083],
>     PARAMETER["false_northing",999999.999996],
>      UNIT["US survey foot",0.3048006096012192,
>         AUTHORITY["EPSG","9003"]],
>     AUTHORITY["EPSG","26954"]]
> Origin = (3130375.000000000000000,1615645.000000000000000)
>  Pixel Size = (1.000000000000000,-1.000000000000000)
> Metadata:
>   AREA_OR_POINT=Area
>   TIFFTAG_SOFTWARE=Adobe Photoshop 7.0
>   TIFFTAG_DATETIME=2006:10:27 09:33:52
>   TIFFTAG_XRESOLUTION=72
>   TIFFTAG_YRESOLUTION=72
>    TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
> Corner Coordinates:
> Upper Left  ( 3130375.000, 1615645.000) (105d 2'16.18"W, 39d31'22.13"N)
> Lower Left  ( 3130375.000, 1610645.000) (105d 2'16.50"W, 39d30'32.71"N)
>  Upper Right ( 3135375.000, 1615645.000) (105d 1'12.37"W, 39d31'21.87"N)
> Lower Right ( 3135375.000, 1610645.000) (105d 1'12.71"W, 39d30'32.45"N)
> Center      ( 3132875.000, 1613145.000) (105d 1'44.44"W, 39d30'57.29"N)
>  Band 1 Block=5000x1 Type=Byte, ColorInterp=Red
> Band 2 Block=5000x1 Type=Byte, ColorInterp=Green
> Band 3 Block=5000x1 Type=Byte, ColorInterp=Blue
>
> csharp code:
>
> Gdal.AllRegister();
> Dataset ds = Gdal.Open(infile, Access.GA_ReadOnly);
>  // get the projection
> string proj = ds.GetProjection();
>
> printing 'proj' produces:
>
> "PROJCS[\"unnamed\",GEOGCS[\"NAD83\",DATUM[\"North_American_Datum_1983\",SPHEROID[\"GRS
> 1980\",6378137,298.2572221010002,AUTHORITY[\"EPSG\",\"7019\"]],AUTHORITY[\"EPSG\",\"6269\"]],PRIMEM[\"Greenwich\",0],UNIT[\"degree\",0.0174532925199433],AUTHORITY[\"EPSG\",\"4269\"]],UNIT[\"US
> survey
> foot\",0.3048006096012192,AUTHORITY[\"EPSG\",\"9003\"]],AUTHORITY[\"EPSG\",\"26954\"]]"
>
> _______________________________________________
>  gdal-dev mailing list
>  gdal-dev at lists.osgeo.org
>  http://lists.osgeo.org/mailman/listinfo/gdal-dev
>