Washed out flat areas when degraining

[moviefan]

Hi guys,

I'm currently trying to degrain a (for my taste) really grainy 1080p clip using MC_Spuds and MCTemporalDenoise respectively. The problem is that flat areas look somehow washed out, meaning when the camera is moved they look really unnatural, since there is almost no change in pixel, but in an unnatural way. I hope you know what I mean... Is this a common side-effect of strong degraining? Or is this a side-effect caused by bad parameters, for e.g. badly computed motion vectors?

Regards,
moviefan

[thetoof]

Looks to me like overdegraining... you could try lowering your settings and/or dithering with gradfun2db (if you have banding) or GrainFactory/Addgrain. This (http://forum.doom9.org/showthread.php?t=143014) might interest you.

[g-force]

Try adding "dct=1" to all MVAnalyse lines.

-G

[LaTo]

and/or dithering with gradfun2db (if you have banding) or GrainFactory/Addgrain. This (http://forum.doom9.org/showthread.php?t=143014) might interest you.

MCTemporalDenoise has an internal parameter for this, look at the "flat" parameter (if you want grain, don't forget to set AGstr) ;)

[moviefan]

OK, I'll try that. But I want to emphasize again that it's not only like only killing details too much, it looks a little weird in flat areas when there is a camera movement... Again they tend to look unnatural somehow.

[g-force]

Both MC_Spuds and MCTemporalDenoise have a DCT parameter. Set that to 1 and see if that helps.

[moviefan]

Hm, I tried DCT=1 but it doesn't help much... I think to have figured out the problem (not a solution): When the motion vectors are being calculated, they seem to calculate slightly wrong ones for little movement - thus the flat area (or better the denoised pixel pattern) doesn't change and it looks weird...

[LaTo]

It would be useful to post a sample!
You can also try stabilize=true in MCTemporalDenoise...

[moviefan]

I tried the stabilize option, no help... I'll post a sample later, currently busy with work ;-) Hopefully you'll find a solution and maybe more optimized settings for that source.