Hi, yes that is the mail reporting the error. Thank you for explanation. I see that I have to reintroduce all the staff for GDALRasterIO()
Radim On Wed, Mar 9, 2011 at 8:50 PM, Even Rouault <even.roua...@mines-paris.org> wrote: > Le mercredi 09 mars 2011 19:46:26, Radim Blazek a écrit : >> Hi, >> > > Skimming qgis mailing list, I read this http://lists.osgeo.org/pipermail/qgis- > developer/2011-March/013291.html > > Was it the report you were refering too ? If yes, then the report gives an > interesting hint. You must be aware that the warping code does not take > advantage of overviews (it is intended to operate on the full-resolution > raster, and not for downsampling as Frank underlined), so you will have really > bad performance comparing too GDALRasterIO() if the output dimensions are much > smaller than the input window size. > >> GDALWarpOperation.ChunkAndWarpImage was reported to be extremly slow >> on larger geotiff (over 1GB). Is it possible that it is much slower >> with respect to GDALRasterIO() even without reprojection? Should I >> return to 'manualy' reading data via GDALRasterIO() + fidling with >> data extents and cells alignement? I thought that GDAL >> ChunkAndWarpImage will do it even faster, possibly knowing better (?) >> various formats nature. >> >> Is there way to tune somehow performance? Currently no reprojection >> and GRA_NearestNeighbour. >> >> Still the same code which I posted before >> http://trac.osgeo.org/qgis/browser/trunk/qgis/src/providers/gdal/qgsgdalpro >> vider.cpp?rev=15400#L625 >> >> Thanks for help. >> Radim >> _______________________________________________ >> gdal-dev mailing list >> gdal-dev@lists.osgeo.org >> http://lists.osgeo.org/mailman/listinfo/gdal-dev > _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
