[Qgis-developer] Bug in rendering Rasters in QGIS 2.4 2.6 and 2.8 in Windows

[kimaidou]

Hi,

This seems to be a bug.. As a workaround, waiting for the bug fix, have you
tried to build pyramids for this raster ? QGIS would then read the raster
from the pyramids when zooming out of raster native resolution. You can do
it in the raster properties dialog.

Michael

2015-04-01 14:21 GMT+02:00 Frank Sokolic <sokolic at worldonline.co.za>:

> I can confirm this behaviour. I am getting it when displaying a
> georeferenced jpg using QGIS 2.8.1 64 bit (standalone installer) running on
> Windows 8.1.
>
> When zooming in or out the raster image sometimes doesn't display. I've
> tried it with OTF both on and off and the bug still occurs.
>
> I've also tried changing the rendering behaviour in the Options >
> Rendering dialogue. The bug occurs irrespective of whether "User render
> caching" and "Render layers in parallel" are on or off.
>
> Regards, Frank.
>
>
>
>
> On 01/04/2015 13:04, SBP wrote:
>
>> Dear All,
>> I had posted this in QGIS users list but I did not get any feedback. While
>> using the latest QGIS 2.8 ( 64 bit ) in Windows XP/7/8/8.1 in 6 laptops, I
>> found that large ( 300+ mb Landsat with 6 band image )raster images failed
>> to redraw while I zoomed in/out or while panning. This behaviour was so
>> random that I was forced to recommend 2.2 to all the users who are
>> supported
>> by my team.
>>
>> It is not possible to use raster images for interpretation as the images
>> do
>> not appear when we zooming or panning. I have placed a video where I have
>> compared the behaviour in 2.8 vs 2.2. A raster and a vector are shown. You
>> will be able to see that the raster disappears randomly and does not
>> redraw
>> even if we pan or zoom. It reappears randomly.
>>
>> Video Link : https://www.youtube.com/watch?v=Wjly6C445uE&feature=youtu.be
>>
>> I tested this in Macbook Pro with Qgis2.6 and I did not see this problem
>> so
>> it might be only seen in windows systems.
>>
>> I hope this will be looked into at the earliest.
>>
>> Thank you for your time.
>> Regards,
>> Sitansu Pattnaik
>> kCube Consultancy Services
>>
>>
>>
>> --
>> View this message in context: http://osgeo-org.1560.x6.
>> nabble.com/Bug-in-rendering-Rasters-in-QGIS-2-4-2-6-and-2-
>> 8-in-Windows-tp5196427.html
>> Sent from the Quantum GIS - Developer mailing list archive at Nabble.com.
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