[Qgis-developer] Raster providers

[Radim Blazek]

I fact, I forgot to write a piece of logic, there is a shift.

Radim

On Thu, Mar 10, 2011 at 8:13 PM, Radim Blazek <radim.blazek at gmail.com> wrote:
> 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 --
>>
>>
>