[Qgis-developer] Raster providers

Giovanni Manghi giovanni.manghi at gmail.com
Wed Mar 9 14:30:31 EST 2011


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 --



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