[Gdal-dev] OGR Spatial Questions
pvongaza at northwestel.net
Mon Jan 17 20:37:55 EST 2005
I've just begun my long intended projected of replacing ("gutting") my
attempts at projection support with your OGR. What I've done is compile
a small DLL with the core ORG spatial routines. I'm testing by reading
Geotiffs (UTM and Albers) and trying to get Lat/Long screen coordinates.
Running into some trouble. First I tested with some of your examples:
OGRSpatialReference oUTM, *poLatLong;
oUTM.SetProjCS("UTM 17 / WGS84");
oUTM.SetWellKnownGeogCS( "WGS84" );
oUTM.SetUTM( 17 );
poLatLong = oUTM.CloneGeogCS();
poTransform = OGRCreateCoordinateTransformation( &oUTM, poLatLong );
Works fine. Then I load a geotiff and try the following:
char *pszProjection = GTIFGetOGISDefn(gtif, &defn );
// string looks like it should
OGRErr i = oSRS.SetProjection( pszProjection );
To this point seem ok.
poLatLong2 = oSRS.CloneGeogCS();
NADA, return NULL. Am I missing a key step in setting up projections
form geotiffs? Could this be related to proj.dll (I using the
precompiled binary from the proj4 site)? Before I start digging I'm
hoping there is an easy solution.
This is my first go at your code and using the proj4 dll.
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