Re: [gdal-dev] Rotate unreferenced tiff file by -90 degrees
On 11-03-17 05:09 AM, Wesley Roberts wrote: Dear gdal'ers I am working with TRMM rainfall data from an HDF5 file (converted from hdf4 to hdf5). I am able to use gdal_translate to extract the gridded data from the HDF file using the following command. gdal_translate -of GTiff HDF5:3A25.071201.6A.h5://DATA_GRANULE/PlanetaryGrid2/e_surfRainMean2 test.tif Gdal_translate works a treat and writes out the test.tif file perfectly, however, the file is unreferenced and needs to be rotated by -90 degrees. Is it possible to do this using gdal_translate or do I need to make use of gdalwarp as well? My tiff world file needs to look something like this 0.50 0.000 0.000 -0.50 -179.75 36.75 Am I correct in assuming that a suitable proj4 statement might do the trick, wrt assigning projection info and defining rotation? If so can someone point me towards a document explaining the various proj4 declaration parameters, or give me some advice on how to go about getting the data properly referenced. Wesley, I think the easiest approach is to prepare a worldfile representing the current georeferencing in east-up or west-up orientation. Then use gdalwarp to transform it to north up. gdalwarp input.tif output.tif For east up I think the world file might look something like: 0.0 0.5 0.5 0.0 top-left-x top-left-y You might need to fiddle around with the orientation a bit to get it right. Best regards, -- ---+-- I set the clouds in motion - turn up | Frank Warmerdam, warmer...@pobox.com light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush| Geospatial Programmer for Rent ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] Rotate unreferenced tiff file by -90 degrees
On 2011-03-17 15:34, Frank Warmerdam wrote: On 11-03-17 05:09 AM, Wesley Roberts wrote: Dear gdal'ers I am working with TRMM rainfall data from an HDF5 file (converted from hdf4 to hdf5). I am able to use gdal_translate to extract the gridded data from the HDF file using the following command. gdal_translate -of GTiff HDF5:3A25.071201.6A.h5://DATA_GRANULE/PlanetaryGrid2/e_surfRainMean2 test.tif Gdal_translate works a treat and writes out the test.tif file perfectly, however, the file is unreferenced and needs to be rotated by -90 degrees. Is it possible to do this using gdal_translate or do I need to make use of gdalwarp as well? My tiff world file needs to look something like this 0.50 0.000 0.000 -0.50 -179.75 36.75 Am I correct in assuming that a suitable proj4 statement might do the trick, wrt assigning projection info and defining rotation? If so can someone point me towards a document explaining the various proj4 declaration parameters, or give me some advice on how to go about getting the data properly referenced. Wesley, I think the easiest approach is to prepare a worldfile representing the current georeferencing in east-up or west-up orientation. Then use gdalwarp to transform it to north up. gdalwarp input.tif output.tif For east up I think the world file might look something like: 0.0 0.5 0.5 0.0 top-left-x top-left-y You might need to fiddle around with the orientation a bit to get it right. Best regards, But presumable the pixel sizes (1st 4th) would not be zero? -- === Zoltan Szecsei PrGISc [PGP0031] Geograph (Pty) Ltd. P.O. Box 7, Muizenberg 7950, South Africa. 65 Main Road, Muizenberg 7945 Western Cape, South Africa. 34° 6'16.35S 18°28'5.62E Tel: +27-21-7884897 Mobile: +27-83-6004028 Fax: +27-86-6115323 www.geograph.co.za === - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1204 / Virus Database: 1498/3510 - Release Date: 03/16/11 ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] Rotate unreferenced tiff file by -90 degrees
On 11-03-17 10:49 AM, Zoltan Szecsei wrote: For east up I think the world file might look something like: 0.0 0.5 0.5 0.0 top-left-x top-left-y You might need to fiddle around with the orientation a bit to get it right. Best regards, But presumable the pixel sizes (1st 4th) would not be zero? Zoltan, For east-up or west-up I believe that the 1st and 4th elements in the world file *should* be zero and the 2nd and 3rd will be the pixel size though I may be mixed up about the signs. More detail on the meaning of the world file is available at: http://en.wikipedia.org/wiki/World_file Best regards, -- ---+-- I set the clouds in motion - turn up | Frank Warmerdam, warmer...@pobox.com light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush| Geospatial Programmer for Rent ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
