On 12-05-04 03:39 PM, Billy Newman wrote:
I ran a quick test and confirmed that gdal.AutoCreateWarpedVRT is returning different results than osr.CoordinateTransformation.I.E. I opened a file using: Dataset dataset = gdal.Open("/images/image.tif"); I grabbed the corner point and used osr.CoordinateTransformation.TransformPoint(), to transform the point into EPSG:4326. I warped the dataset using gdal.AutoCreateWarpedVRT, grabbed the corner point and the corner point was a little different. I am not sure if that is expected behavior or not. Hopefully I am just missing some static files and one of the transformations was not quite right. I tried all the different sampling algos available for the AutoCreateWarpedVRT and that did not make a huge difference. Is warp using a different method to transform the points? If so is that transformation available via the API? I understand that not all calcs may be exact between these two but I would expect the corner point to be almost exact.
Billy, Generally speaking the extents of the warped VRT will be somewhat larger than the original to capture the irregular shape of the source image after warping into the target coordinate system. Best regards, -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, warmer...@pobox.com light and sound - activate the windows | http://home.gdal.org/warmerda and watch the world go round - Rush | Geospatial Software Developer _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
