[mitk-users] Flickering image in render window

[Miklos Espak]

Hi,

I noticed some weird rendering issues.

Screenshot and video here:

https://drive.google.com/drive/folders/0Bz-0EIzNgFvMRXdoR2taeWlnaU0

This happened with MITK 2015.05.2 and Qt4 on CentOS 6, and it's not
consistent, so can't open a ticket.

I am wondering if anyone has seen this, maybe it's been resolved in a newer
VTK/Qt/MITK?


The issue in words:

Three images were loaded into our viewer based on QmitkStdMultiWidget. A
grey scale (T1), a binary mask and an RGB image (DWI). The T1 was at the
bottom layer, the RGB and the mask was over it. The images were not
transparent (opacity=1.0), the mask was rendered as contour.

When you scrolled through the slices, the image is "flickering". When
changing slice, you could see the T1 for the fragment of a second and then
it was covered by the RGB again.

On top of that, an annotation that should only appear in the bottom right
corner, was overlaid on the image with very big letters.

Cheers,
Miklos

[Dinkelacker, Stefan]

Hi,


I'm pretty sure that this is a driver issue, as it looks like wrong blitting in VRAM. There's a slight chance that maybe VTK is involved but I doubt that because of the temporary character of the glitch. Qt may also play a role here if there's context sharing. Is it possible to up- or downgrade the graphics driver? You could also try to deactivate any kind of power saving plan for the GPU. For example, if you have a Nvidia GPU, you can set the PowerMizer mode in the Nvidia Settings to "maximum performance". This solved some rendering issues for me in the past on Linux. It would also explain why the issue is sometimes there and sometimes it is not. Note that the PowerMizer mode setting is not persistent between restarts or even between runs of the Nvidia settings app. If it does the job, you would need to add it manually to the hidden Nvidia settings file in your home directory with a line like "GPUPowerMizerMode=1" (everytime after you ran the Nvidia settings app as it overrides the config file again).


Best,

Stefan

________________________________
Von: Miklos Espak <***@ucl.ac.uk>
Gesendet: Mittwoch, 21. Juni 2017 16:30
An: mitk-users
Betreff: [mitk-users] Flickering image in render window

Hi,

I noticed some weird rendering issues.

Screenshot and video here:

https://drive.google.com/drive/folders/0Bz-0EIzNgFvMRXdoR2taeWlnaU0

This happened with MITK 2015.05.2 and Qt4 on CentOS 6, and it's not consistent, so can't open a ticket.

I am wondering if anyone has seen this, maybe it's been resolved in a newer VTK/Qt/MITK?


The issue in words:

Three images were loaded into our viewer based on QmitkStdMultiWidget. A grey scale (T1), a binary mask and an RGB image (DWI). The T1 was at the bottom layer, the RGB and the mask was over it. The images were not transparent (opacity=1.0), the mask was rendered as contour.

When you scrolled through the slices, the image is "flickering". When changing slice, you could see the T1 for the fragment of a second and then it was covered by the RGB again.

On top of that, an annotation that should only appear in the bottom right corner, was overlaid on the image with very big letters.

Cheers,
Miklos

[Miklos Espak]

Hi Stefan,

thanks for the hints, they are very useful.

The machines have Nvidia cards, indeed. I could not reproduce the bug in
another machine that has an older driver, but then it did not occur in the
first machine again, either (after just restarting the app), so I do not
think it is the version. These are machines for clinical trials, so
upgrading/downgrading packages is difficult because then everything needs
to be revalidated again.

I will try first to force this PowerMizer mode off then to upgrade the
driver on the test machine to see if I can reproduce the problem.

Cheers,
Miklos


On 22 June 2017 at 08:09, Dinkelacker, Stefan <

Post by Dinkelacker, Stefan
Hi,
I'm pretty sure that this is a driver issue, as it looks like wrong
blitting in VRAM. There's a slight chance that maybe VTK is involved but I
doubt that because of the temporary character of the glitch. Qt may also
play a role here if there's context sharing. Is it possible to up- or
downgrade the graphics driver? You could also try to deactivate any kind of
power saving plan for the GPU. For example, if you have a Nvidia GPU, you
can set the PowerMizer mode in the Nvidia Settings to "maximum
performance". This solved some rendering issues for me in the past on
Linux. It would also explain why the issue is sometimes there and sometimes
it is not. Note that the PowerMizer mode setting is not persistent between
restarts or even between runs of the Nvidia settings app. If it does the
job, you would need to add it manually to the hidden Nvidia settings file
in your home directory with a line like "GPUPowerMizerMode=1" (everytime
after you ran the Nvidia settings app as it overrides the config file
again).
Best,
Stefan
------------------------------
*Gesendet:* Mittwoch, 21. Juni 2017 16:30
*An:* mitk-users
*Betreff:* [mitk-users] Flickering image in render window
Hi,
I noticed some weird rendering issues.
https://drive.google.com/drive/folders/0Bz-0EIzNgFvMRXdoR2taeWlnaU0
This happened with MITK 2015.05.2 and Qt4 on CentOS 6, and it's not
consistent, so can't open a ticket.
I am wondering if anyone has seen this, maybe it's been resolved in a
newer VTK/Qt/MITK?
Three images were loaded into our viewer based on QmitkStdMultiWidget. A
grey scale (T1), a binary mask and an RGB image (DWI). The T1 was at the
bottom layer, the RGB and the mask was over it. The images were not
transparent (opacity=1.0), the mask was rendered as contour.
When you scrolled through the slices, the image is "flickering". When
changing slice, you could see the T1 for the fragment of a second and then
it was covered by the RGB again.
On top of that, an annotation that should only appear in the bottom right
corner, was overlaid on the image with very big letters.
Cheers,
Miklos