Hi, I'm not sure about this problem, I suspect cascading the vrt datasets should normally work. Could you provide your complete C# example to produce the output and the gdal_warp command line to examine the difference?
Best regards, Tamas 2009/5/31 edomazlicky <[email protected]> > > I am trying to warp a NAD27 UTM file to Google Mercator 900913. My > understanding is that for this to happen you have to first warp the file to > WGS84 and then to 900913. I have tried going straight from NAD27->900913 > and > I get projection errors similar to if you plotted a WGS84 coordinate on a > NAD27 map. So to accomplish this two-step warp I have been trying to do > something kind of like this: > > Dim oWGS84 As New OSGeo.OSR.SpatialReference("") > ' WGS84 UTM Zone 10 > oWGS84.ImportFromEPSG(32610) > Dim wgs84_wkt As String = "" > oWGS84.ExportToPrettyWkt(wgs84_wkt, 0) > InterMed = OSGeo.GDAL.Gdal.AutoCreateWarpedVRT(SrcGdalDataSet, src_wkt, > wgs84_wkt, eReSample, 0.125) > GdalDataSet = OSGeo.GDAL.Gdal.AutoCreateWarpedVRT(InterMed, wgs84_wkt, > dst_wkt, eReSample, 0.125) > > Where src_wkt contains the NAD27 WKT and dst_wkt contains the 900913 WKT. > This doesn't work- I am getting the same results I get if I try to go > straight from NAD27->900913. However if instead I warp the file in > gdal_warp > first to WGS84 and then go from that to 900913 it works fine. Is there > anyway to warp these files without making a new file fist? I would like for > it all to be done in memory without messing with temporary files or calling > gdal_warp externally. > -- > View this message in context: > http://n2.nabble.com/Warping-a-warped-file-C--bindings-tp3003215p3003215.html > Sent from the GDAL - Dev mailing list archive at Nabble.com. > > _______________________________________________ > gdal-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/gdal-dev >
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