Help on degraining methods?

aymanalz · 20th September 2019, 00:16

Hi,

I am trying to re-encode an HD (Bluray) movie that is extremely grainy. I would like to degrain it, and was wondering which method/settings I should choose. Having tested out most of the options in Vapoursynth, I think my choices boil down to MCTemporalDenoise, KNLmeansCL and SMdegrain. The first seems easy to use, the second utilizes my GPU and leaves the CPU for encoding, and the third has a lot of options that can be tweaked (but I don't know what they do).

So which one should I choose? Could somebody give a sample of options for SMdegrain that is relevant to this particular case? (Heavy grain in an otherwise high bitrate, high quality clip.)

Is KNLmeansCL good for degraining, or is it more of a general denoiser? Can the parameters be tweaked to make it remove mostly grain alone?

TIA.

hello_hello · 20th September 2019, 02:37

I can't help with SMDegrain, but you forgot one. TemporalDegrain2

I often use QTGMC() in progressive mode, because it's faster than some of the denoising scripts and does a pretty good job. Something like:
QTGMC(InputType=1, Preset="Medium", EzDenoise=1.5)

Try Preset="Slow" or slower first, but because QTGMC stabilises the picture, any grain left behind is stabilised, which can look a bit odd because grain normally isn't stable. Faster presets stabilise a little less. Increase or decrease the EzDenoise value as required. I try not to go over 2.5 if possible, as that's roughly where it starts to noticeably blur (to my eyes). How much blurring you're willing to live with is personal preference.

20th September 2019, 00:16	#1 \| Link
aymanalz Registered User Join Date: May 2015 Posts: 68	Help on degraining methods? Hi, I am trying to re-encode an HD (Bluray) movie that is extremely grainy. I would like to degrain it, and was wondering which method/settings I should choose. Having tested out most of the options in Vapoursynth, I think my choices boil down to MCTemporalDenoise, KNLmeansCL and SMdegrain. The first seems easy to use, the second utilizes my GPU and leaves the CPU for encoding, and the third has a lot of options that can be tweaked (but I don't know what they do). So which one should I choose? Could somebody give a sample of options for SMdegrain that is relevant to this particular case? (Heavy grain in an otherwise high bitrate, high quality clip.) Is KNLmeansCL good for degraining, or is it more of a general denoiser? Can the parameters be tweaked to make it remove mostly grain alone? TIA.

20th September 2019, 02:37	#2 \| Link
hello_hello Registered User Join Date: Mar 2011 Posts: 4,829	I can't help with SMDegrain, but you forgot one. TemporalDegrain2 I often use QTGMC() in progressive mode, because it's faster than some of the denoising scripts and does a pretty good job. Something like: QTGMC(InputType=1, Preset="Medium", EzDenoise=1.5) Try Preset="Slow" or slower first, but because QTGMC stabilises the picture, any grain left behind is stabilised, which can look a bit odd because grain normally isn't stable. Faster presets stabilise a little less. Increase or decrease the EzDenoise value as required. I try not to go over 2.5 if possible, as that's roughly where it starts to noticeably blur (to my eyes). How much blurring you're willing to live with is personal preference.