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Flickering / unstable filtration

Posted: Wed Jun 03, 2015 3:27 am
by VHSobsessive
There is a filtration issue I cannot get rid of in NV3 (and the NV4 demo). It involves areas of the image which lack texture or defined edges, e.g. out of focus background areas.

The temporal filter seems unable to realise that these background areas are entirely static, even with a temporal radius of 5, and increased threshold. I usually have the spatial filter switched off ... it does not help this issue when switched on.

Virtualdub, Win7-64.

Image

Here is an XVID showing the problem (NV4, temp radius 2, thresh. max, spatial filter off] :

https://www.dropbox.com/s/dgvw3aifn3qt5 ... 3.avi?dl=0

Clip 1 : upper left background; clip 2 : lower left wall; clip 3 : centre-right wall spotlight; clip 4 : centre-right yellow jacket reflection.

And a high-bitrate MJPEG of the unfiltered problem clips ... I have added a few extra frames to help profile building [click download, top right] :

https://www.dropbox.com/s/mldieiktonmtg ... 3.avi?dl=0

I don't think the profile is very relevant but here is what I have been using :

https://www.dropbox.com/s/d2kdd5jw0a3yn ... 0.dnp?dl=0

Are you able to reproduce this, and have you any suggestions on how to resolve this ?

Thank you for this otherwise excellent filter.

Posted: Wed Jun 03, 2015 1:18 pm
by NVTeam
Yes, I can see that flickering. It is not unstable filtration, the flickering is present in the original frames as well. Removing the noise just makes that flickering more visible.

Unfortunately, we do not currently have any dedicated means to address that specific problem of the source clip. That may be one of the directions of our future development.

Thank you,
Vlad

Posted: Wed Jun 03, 2015 5:07 pm
by VHSobsessive
Thank you. Please consider it. NV2 deals with these difficult areas perfectly. Hopefully something can be done.