[Qgis-user] Slow to open huge rasters

[Andrea Peri]

Hi Radim,
thx for hint.

I try to set the contrast enhancement to NO STRETCH
and
Limits to minimum / maximum ,
Apparently seem to have no result. The qgis is locked in opening of
raster, but of course I should wait for some hours to see if some
improvements is occursed.

A.


2015-07-30 9:52 GMT+02:00 Radim Blazek <radim.blazek at gmail.com>:
> On Thu, Jul 30, 2015 at 9:19 AM, Andrea Peri <aperi2007 at gmail.com> wrote:
>> Hi,
>>
>> I have a GeoTiff raster of 24Gbyte, floating point (Float64) with 11
>> bands and fomat geotiff.
>>
>> When try to open it with qgis 2.8.1 I see it take a really uge time to
>> open it (about 10 hours).
>> Initially I guess that was a time due to the huge dimension, but after
>> the qgis show it.
>> I notice that it is reallyquickly to zoom and pan.
>> I don't understand why this difference between the open time and zoom/pan time.
>>
>> My first suspect was that qgis want to calculate the statistics in first open.
>> But after a check with gdalinfo I see the statistics are available
>> also in original tiff.
>
> QGIS defaults are stretch to 2/98% cut, try to set in
> Options > Rendering > Rasters
> Contrast enhancement: No stretch  or  Limits: Minimum / maximum
>
> Radim
>
>
>> So I dont know really why it take so more time to open it.
>>
>> I hope to find some setting to reduce the pen time for this kind of images.
>>
>> Thx,
>>
>> A.
>>
>> --
>> -----------------
>> Andrea Peri
>> . . . . . . . . .
>> qwerty àèìòù
>> -----------------
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-- 
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Andrea Peri
. . . . . . . . .
qwerty àèìòù
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