Cleaning artifacts and graining from non-anime MPEG-2 video (source examples)

[chipzoller]

I've got several questions to ask in regard to the thread title, all of which because I'm at least somewhat familiar with filtering anime/cartoon sources but not at all with real-life video (nomenclature?).

1.) Since I will not and cannot ask which filter(s) is(are) best to use, I would in its place ask for a consensus on a general filter combination that is most often used in cleaning sources of this type. It is important to note that I am referring to grainy MPEG-2 DVD sources and NOT VHS or any other sort of analog capture (although some of the filters and usages will no doubt apply to both).

2.) From searching the forum and the 'net I have been able to find no resources that directly address this issue, so I would be most appreciative if someone might point me in the general direction of such.

4 sample shots:
http://arches.uga.edu/~czoller/1.png
http://arches.uga.edu/~czoller/2.png
http://arches.uga.edu/~czoller/3.png (http://arches.uga.edu/~czoller/2.png)
http://arches.uga.edu/~czoller/4.png (http://arches.uga.edu/~czoller/2.png)

The post here (http://forum.doom9.org/showthread.php?p=847091#post847091) using fft3dfilter seems to give good results but I want to consider other plugins. I just don't know how to begin researching and testing such plugins for something like this.

Thanks for any help. I'll edit with more questions as I've forgotten some just now.

[Mug Funky]

I am referring to grainy MPEG-2 DVD sources and NOT VHS or any other sort of analog capture (although some of the filters and usages will no doubt apply to both)

hehe... the screenshots you gave suffer (slight) rainbowing and crawlies, evidence that the DVD was actually an analog capture, albeit a good quality one.

there's actually not much grain at all on this transfer. there's analog artefacts, like oversharpening, dot crawl and rainbows. it's probably transferred from Laserdisc, or run off a digital deck via analog (this happens too much).

try:

dedot
dehalo_alpha (with r_x larger than r_y)
degrainmedian

you should get a pretty smooth picture out of that. dehalo_alpha might not be enough for the oversharpening, but it shouldn't impact quality too much either way.

you might also want to run a de-blocker on it at low settings.

[chipzoller]

Well, I tried to pick some areas with the most amount of graining, but it just happened that this episode (Nero Wolfe) didn't have exactly what I was looking for.

So let's just say it DID have lots of graining as most of these episodes do. Is there a generally-used set of filters for taking care of that?

[Mug Funky]

it very much depends on your destination medium.

if you're going mpeg-2 and burning DVDs, then you could get away with just fixing the analog stuff and not touching the noise (removing the oversharpening will ever-so-slightly reduce the grain too).

really, it's much better to leave in a little noise than remove it all and half the detail.

nero wolfe, huh? that's that detective show, right? if it's what i think it is, it'll have been shot on 16mm, so that'd be considerably grainy, but from those screens you posted it's not bad. so i think it's already had noise reduction on it at some stage. all you need to do is remove the noise that came in since then :)

degrainmedian is quite powerful, and if it's not giving good results (big grains are turning into sharp-edged splotches), then give fft3dfilter a go - it's incredibly powerful, but can be pushed too far (edges and detail will suffer). there's plenty of threads on setting up fft3d, so search will help.

[chipzoller]

thanks for the reply. Perhaps I should have stated at the beginning of all this that my destination medium would be computer file (x264 & AAC in matroska) backup.

nero wolfe, huh? that's that detective show, right?

Yes. Famous character based on the popular novels by Rex Stout. And yes this was shot on 16mm, although some of the episodes look well, some other are still surprisingly grainy.

In any case, I'll look into all your suggestions. Thanks.

[chipzoller]

Mug Funky,

Ok I now have a good example of what I'm trying to eliminate. This comes from one of my James Bond special edition DVDs (R1) called "Dr. No" which was from 1962 and thus full of grain.

script:


dedot()
DeGrainMedian(limitY=8,limitUV=15,mode=0)
dehalo_alpha(rx=3.0,ry=2.0)



Before
http://arches.uga.edu/~czoller/orig.jpg

After
http://arches.uga.edu/~czoller/filtered.jpg

If you like I can also post a small clip from the VOB for you to experiment with.

The results are good, but is this as good as we can do?

[Pookie]

FYI, dunno how important the Bond flicks are to you, but the remastered versions will be out in Sept-Oct-Nov. All done by Lowrey Digital, who used their 600 Mac G5s render farm to restore Star Wars and THX-1138 (btw, THX-1138 looks spectacular).

I've noticed with many pre-1980 films that degraining leaves you with smear and little left to sharpen.

No Sharpening

http://fileserver1.jpghosting.com/images/tn_514no-nr_1b4175415c02b7f6a73ce9e6c0144d8d.png (http://fileserver1.jpghosting.com/images/514no-nr_1b4175415c02b7f6a73ce9e6c0144d8d.png)

Degrained,Sharpened, but not necessarily "better"

http://fileserver1.jpghosting.com/images/tn_514sharpened_979cbb1f1bd5b2f617a8ff8f05de2806.png (http://fileserver1.jpghosting.com/images/514sharpened_979cbb1f1bd5b2f617a8ff8f05de2806.png)

[chipzoller]

http://www.macworld.co.uk/news/index.cfm?NewsID=14919

I'm glad you pointed this out...I had no idea. I'm just a little upset that I now have to buy the complete collection ALL OVER AGAIN as I spent a couple hundred bucks buying the special editions that started coming out around 2000-2001! Oh well, at least these can serve as testing grounds for avisynth scripts :)

I also tried what was suggested in this (http://forum.doom9.org/showthread.php?p=814426#post814426) post. I can't find anything better than the code I previously posted.

[crypto]

The Bond clip degraining is impressive. I didn't know, that it can be done this well. Thanks for sharing the script.

[chipzoller]

Pookie,

I actually think the first example was better than the second, but only VERY slightly so. The difference is extremely minimal in those two comparisons. I'm looking to achieve much higher levels of degraining but don't want the image to become too soft. So I'm wondering if maybe I've smoothed the image in my examples too much, or if I can get better degraining results.