Martin, Could you paste the output of gdalinfo on the .sid file on both environments, and each time indicate what 'gdalinfo --version' reports ? It might be possible that the issue is at the source rather than at the warping.
Even > I seem to be having a few warping problems using OGRCoordinateTransformation > as the warped images do not appear to have the correct co-ordinates. > To establish what was going on I have come across a curious issue that may > indicate the problems that I am having. > > On a separate machine I have QGIS 2.4.0 installed as I use this for > verification as it also uses GDAL. > > I took a MrSID file (NAD83) and warped it in QGIS to a GeoTiff (WGS84). > > This worked successfully and produces a proper square tile with the correct > co-ordinates. > I then copied the command line that QGIS gives you shown below: > > gdalwarp -overwrite -t_srs EPSG:4326 -of GTiff > E:/Stuff/Maps/georgiaville_se.sid E:/Stuff/Maps/testGDAL.tif > > and ran this on the development machine (where I have noticed the gdal > issues) in a command prompt using 'pure' gdal. > This did not give any errors and a tif file was generated. > > However when this tif from the 'pure gdal' was viewed, it was skewed with > black borders and about 3 degrees in the longitude out and smaller error in > the latitude. (These are the exact same errors that OGRCoordinateTransform > gives) > > I then did a gdalinfo on both the generated tiff files and noticed these > differences: > > From the QGIS generated file: > > Files: C:\Stuff\MrSID\Georgiaville_SE\testQGIS2.tif > Size is 6133, 6131 > Origin = (-71.562566138751492,41.937520670986764) > Pixel Size = (0.000010201993468,-0.000010201993468) > > From the gdal generated file: > > Files: C:\Stuff\MrSID\Georgiaville_SE\testGDAL.tif > Size is 6331, 6217 > Origin = (-74.311201444644681,41.904608529793123) > Pixel Size = (0.000010289425691,-0.000010289425691) > (There were other differences in the Upper Left etc but these are the key > diffs. The Coordinate System is exactly the same) > > What is going on? Why the differences between the two? What am I doing wrong? > I have recently upgraded to gdal 1.11.0 and proj4 4.8.0. All the env > variables etc are setup e.g. GDAL_DATA, PROJ_LIB and point to the correct > directories so I must have missed something else? > > Hope somebody can help. > > Thanks > > > > ________________________________ > *****CONFIDENTIALITY NOTICE***** > > This electronic message transmission contains information which may be > confidential. If you are not the intended recipient, be aware that any > disclosure, copying, distribution or other use of the content of this > information is prohibited. If you have received this communication in error, > please notify the sender immediately by email and delete the original > message. > > Northrop Grumman UK Limited is company registered in England with No. > 05989428, Registered Office: 2nd Floor, Clareville House, 26-27 Oxendon > Street, London SW1Y 4EL. > -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
