Bug report #3588
new raster provider: very slow
|Affected QGIS version:||Regression?:||No|
|Operating System:||All||Easy fix?:||No|
|Pull Request or Patch supplied:||Resolution:||fixed|
|Crashes QGIS or corrupts data:||Copied to github as #:||13648|
I'm testing the new raster capabilities of QGIS with bunch of big tiff rasters (> 1gb, sometimes > 2gb), with internal tiles and/or overviews.
What I'm seeing is that now those rasters take quite a lot (making
qgis not responsive for a while) to be rendered, before the merge it was all much quicker.
on QGIS 1.6 a 1.7GB geotiff with tiles and overviews opens in (more or less) 1 sec., in trunk now takes (more os less) 1 minute!
After the raster show in the canvas, also opening its properties take a long time. Before the merge was immediate.
Zooming and panning it is also much slower than before the merge.
Overall it seems like that tiles and overviews are ignored or not read, but to me seems that also opening big tiffs (> 1gb) without internal tiles and/or overviews takes a lot more than before the merge.