[gdal-dev] GDALWarpOperation.ChunkAndWarpImage slow on large tiffs

[Radim Blazek]

Hi,

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/qgsgdalprovider.cpp?rev=15400#L625

Thanks for help.
Radim