> > > Hi, Even > > I faced this problem before. I checked under debugger and saw that vrt > sources were not creating overviews. So, gdal was making long RasterIO > executions to the source raster, but not overviews. I provided a patch > which took the overviews from origin raster and wrapped them too. May be > this is not so elegant solution, but it works and speed up work with > wrapped rasters considerably. > > I don't thik that qgis under GDB/DDD will give any additional > information (one will just see long RasterIO executions). > > But I can still try to use GDB if you think this might help. >
Dmitry, I don't deny the problem you describe. And your solution sounds reasonable. But without more precise context from Andrea, I just wanted to be sure that it was the precise case that Andrea ran into. There might be other issues involved (like histogram or statistics computations that can take a long time, but admitedly, I wouldn't expect the VRT overhead to be significant) and displaying the stack can show which first GDAL API call is involved. _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
