[Qgis-developer] Raster providers

[Radim Blazek]

I have changed how GDAL provider reads the data, it should be fast again.


BUT! I am not absolutely sure that resampling is perfect and the
nearest neighbour is alway nearest. I dont think however that anybody
could notice that in normal work. I would appreciate however if
somebody with fresh brain could check the alignment fiddling.
http://trac.osgeo.org/qgis/browser/trunk/qgis/src/providers/gdal/qgsgdalprovider.cpp#L529

More pointers - more crashes expected!

Radim


On Wed, Mar 9, 2011 at 8:30 PM, Giovanni Manghi
<giovanni.manghi at gmail.com> wrote:
> Hi,
>
> On Tue, 2011-03-08 at 20:17 +0100, Radim Blazek wrote:
>> Merged to trunk.
>
>
> I'm testing the new raster capabilities of QGIS and I would like to have
> your opinion on a certain matter before eventually filing a ticket.
>
> I have a 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.
>
> As exemple:
>
> 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.
>
>
> anyone experiencing the same?
>
>
> cheers
>
> -- Giovanni --
>
>