DegrainMed Faster Alternative for light compression artifacts in HD Videos?

[MrBiggles]

In Non-MT I get around 30fps on my 4.2Ghz 8 core CPU when downscaling 1080i TV recordings to 720p and denoising with DegrainMedian.

Am I correct in saying that DegrainMedian is overkill for this purpose as HD footage only has light compression artifacts? So I was wondering if there's a lighter and faster denoiser?

[poisondeathray]

Very fast, very light is RemoveGrain(1) . It does almost nothing, just remove very fine noise

You can have a look at KNLMeansCL if you have a decent GPU . It's looks to be one GPU filter in avisynth (and vapoursynth) that is actually useful and stable. The other previous GPU implementations of various filters tended to be buggy or plagued with issues

You have to experiment with different settings/ filters because everyone has different tastes/goals. Something that is "overkill " for someone is perfectly fine for someone else

[MrBiggles]

Thanks. Is there anything else as I don't want to use the GPU filter.

[Groucho2004]

Is there anything else as I don't want to use the GPU filter.

SMDegrain is highly configurable, although probably too slow for you even with the fastest settings.

Why would you not use a GPU filter?

[MrBiggles]

It says it only works on progressive footage.

[Groucho2004]

It says it only works on progressive footage.

Where? The page on avisynth.nl clearly states that it supports interlaced content.

[MrBiggles]

The readme file

[poisondeathray]

You're referring to KNLMeansCL ? There are ways to use it (or any filter) with interlaced footage - you separate the fields and apply to grouped even and odd fields

But aren't you deinterlacing, resizing to 720p ? Or what do you mean by "downscaling" ?

In Non-MT I get around 30fps on my 4.2Ghz 8 core CPU when downscaling 1080i TV recordings to 720p and denoising with DegrainMedian.

[MrBiggles]

Yes I'm referring to KNLMeansCL. Do you have a couple of scripts please so I know the best way to use it. One for 1080i and one for downscaling 1080i to 720p 50fps?

I thought downscaling means resize to a lower resolution? i.e. 1080i to 720p?

I've only got a cheap £30 graphics card although it has VP5. Will that still work? Does the filter only use the GPU or does it use the CPU as well?

[poisondeathray]

Yes I'm referring to KNLMeansCL. Do you have a couple of scripts please so I know the best way to use it. One for 1080i and one for downscaling 1080i to 720p 50fps?

I thought downscaling means resize to a lower resolution? i.e. 1080i to 720p?

I've only got a cheap £30 graphics card although it has VP5. Will that still work? Does the filter only use the GPU or does it use the CPU as well?

There is no "best" way, you need to adjust the settings to your source footage and personal tastes

You can't downscale interlaced footage without deinterlacing, or without using an interlaced aware resizing method

It will probably be too slow on that GPU, so should probably spend your time investigating other methods

[MrBiggles]

I know how to downscale mate, I was just wondering why you asked me what I meant by downscaling as I thought it was fairly obvious what downscaling means i.e. 1080i to 720p.

I can get a much better graphics card but I just want to test what the video looks like after the filter is used on it. I find the way these readme files are written is not very intuitive for people who don't know programming - I don't understand the instructions.

Do you have an example script please for 1080i to 720p 50fps using KNLMeansCL? That way I can work from there once I see what the script looks like.

[poisondeathray]

If you've converted to 720p properly - it's progressive and no longer interlaced. It wasn't clear that you understood that when you commented that it only worked on progressive footage

downscaling 1080i TV recordings to 720p and denoising with DegrainMedian.

That implies that you are denoising after "downscaling" so working on progressive footage .

Filtering actually works better when video is progressive . When you use the separate odd/even fields method for interlaced video, there is inefficient temporal filtering between grouped even/odd fields - you can get noise fluctuations between them.




There are examples in the KNLMeansCL thread. Just copy & paste them, then adjust them to your tastes. Or start with the default settings. You can use spatial or temporal modes. Spatial only is much much faster.

KNLMeans only affects Y' plane, U and V are not. If you need chroma denoising as well, you need to filter the U, V planes separately by converting them to Y8 (greyscale), then apply the filter and use YtoUV

eg.

y = KNLMeansCL("whatever settings")
u = UToY8().KNLMeansCL("whatever settings")
v = VToY8().KNLMeansCL("whatever settings")
YToUV(u, v, y)

[MrBiggles]

Thanks. Is there a simple explanation of the difference between spatial & temporal. All I understand about temporal after working with McTemporalDenoise is that it removes more noise such as flicker on VHS that DegrainMedian doesn't remove.

Is DegrainMedian a spatial denoiser? Basically I just want KNLMeansCL to do denoising similar to DegrainMedian but not as strong since HD footage barely has any compression artifacts to remove.

What is Y, U & V, & chroma?

[poisondeathray]

Thanks. Is there a simple explanation of the difference between spatial & temporal. All I understand about temporal after working with McTemporalDenoise is that it removes more noise such as flicker on VHS that DegrainMedian doesn't remove.

Is DegrainMedian a spatial denoiser? Basically I just want KNLMeansCL to do denoising similar to DegrainMedian but not as strong since HD footage barely has any compression artifacts to remove.

What is Y, U & V, & chroma?

Spatial means within a single frame only. Temporal means data from adjacent frames are used (they look at n+1, n+2, etc.. frames before and after). Temporal methods are usually stronger, stabilize noise patterns more effectively, but also put you at higher risk of temporal artifacts such as ghosting

DegrainMedian uses spatial/temporal , just read the readme, that's what it's there for

It uses some spatio-temporal limited median method.

In YUV video, the color information is codec separately in color difference channels (u, v) from the greyscale (black and white) information (y). Almost all consumer video uses YUV.
https://en.wikipedia.org/wiki/YUV

[MrBiggles]

DegrainMedian doesn't come with a readme file. The extension's website says "It uses some spatio-temporal limited median method". But it doesn't really say what that means?

Did you make a spelling mistake when you said this as I don't understand what you meant?

In YUV video, the color information is codec separately in color difference channels

What does Chroma denoising mean?

[Groucho2004]

DegrainMedian doesn't come with a readme file.

You must be downloading your stuff from a server in a parallel universe. The package contains a readme in html format, "degrainmedian.html".

[MrBiggles]

That's not a Readme file. A readme file is a README.txt file.

[poisondeathray]

Whatever, in the instructions then. All filters have instructions on how to use them. RTFM

Yes, it' s just a typo. The color is stored separately. Read the link or use Google.

Chroma noise is color noise. Use Google or use search. There are many examples posted. I'm sure you've asked about it when logged in under one of your previous names

[Groucho2004]

That's not a Readme file. A readme file is a README.txt file.

You've got to be f*cking kidding.

[MrBiggles]

I'm sure you've asked about it when logged in under one of your previous names

Don't know who you're confusing me with. This is my only account.

That's not a Readme file. A readme file is a README.txt file.

You've got to be f*cking kidding.

A readme file is a README.txt file. I know that sounds a bit far fetched but that's what most filters and programs come with...

I open the DegrainMedian folder and there's a "degrainmedian" file which won't open in any program (I have show file extensions turned off) and there's also a bunch of other similarly named files that also won't open in any program. The only text files are licence .txt files. So that and the fact that most programs come with a readme file, it wasn't unreasonable to assume that there wasn't an instructions file with the filter.

Groucho you could have just answered the question instead of wasting time moaning about a readme file.

Anyway, thanks everyone for your help.

[Groucho2004]

A readme file is a README.txt file. I know that sounds a bit far fetched but that's what most filters and programs come with...

Not true. Many plugins actually have a nicely formatted HTML documentation (Fizick, Tsp).

I have show file extensions turned off

I haven't used Explorer in years but I vaguely remember this utterly idiotic default setting. I did not expect that anyone would leave it as it is.

Groucho you could have just answered the question instead of wasting time moaning about a readme file.

DegrainMedian doesn't come with a readme file.

...The package contains a readme in html format, "degrainmedian.html".