Denoise software revisited . . .

johnmeyer wrote on 1/4/2008, 6:44 PM

This exact same approach to comparing denoisers was done 18 months ago on the doom9 forum:

What denoiser is the worst ? Objective test attempt

The reason for the "worst" heading is that the doom9 forum rules don't allow discussions of what is the "best" anything. Pretty stupid, but those are their rules.

The problem with that study, and the identical one linked to in Grazie's post is that noise is artifically added and then removed. Most real-world noise is not so uniform, and tends to be different in shaodws than in the highlights. In fact, often the noise is only in the shadows.

The second problem is that in order to remove the human subjective evaluation, the "goodness" of the noise reduction was measured based on how "happy" the encoder is with the results. This has virtually nothing to do with how the result actually looks, and can ignore huge artifacts introduced by the noise reduction process. Since artificial artifacts are in fact the biggest problem with noise reduction, this almost completely invalidates the approach.

Finally, the study looked mostly at filters available for VirtualDub. I have used almost all of them at one time or another, and they seemed very good many years ago. That is, until I figured out how to use AVISynth and discovered the filters available for that platform. They have two HUGE advantages over anything available for Vegas or VirtualDub. First, they are really fast. Second, they can be used in a script that includes motion compensation. As I posted in the last thread about denoising, the "ultimate" noise reduction involves temporarily repositioning the current video frame to match either the frame before or the frame after (by moving it X-Y and also rotating). Only then is the denoiser allowed to work by comparing the frame to its adjacent counterparts. This dramatically improves the pixel matching by eliminating movement caused by panning or other camera movement.

As I have said before, if someone wants to post some video that needs denoising, I would be happy to process it using the tools I have learned to use after almost six years of experimentation and trial & error. While there is no single magic bullet, using FFT3D with motion compensation provides results far better than anything else, including the popular Neat Video, and also much better than the VD denoisers (which includes MIke Crash's excellent implementation of one of those VD denoisers).

farss wrote on 1/5/2008, 2:14 AM

If you want to see some very impressive (and very expensive) restoration being done dig through the S&W website and have a look at the demo of the their Archangel Ph.C,
link to get you started, the link to the Archangel is down the bottom of the page:

http://www.snellwilcox.com/products/conversion_restoration/products.php

The interesting things is that the first thing this box does is as John says, to align the frames. That it can weave it's magic in real time is very impressive, I guess thow enough money at a problem and almost anything is possible. If you watch the demo right though the quality of what they can extract from crud (low band UMatic) is very impressive. A software only non realtime version should sell well, I don't think $10K would be asking too much.

Bob.

Grazie wrote on 1/5/2008, 2:27 AM

Thank you John, for casting an eye and then writing your comments. Very intelligent. You have singularly explained something that was sticking in my craw - the subjectivity bit. I'm using NV now and it does have a frame thingie? Not the same? I guess not. Maybe it isn't the frame thingy you are referring to?

My initial work with NV is as a Vegas Plugin:

1] - A waterfall, looks as if motion blur has been added. Unfair for me to do that, I know.

2] - Getting "pancake-makeup" dough faced people.

I shall persist with it. There will be a time when I'll call it into play - over and above Mike Crash's.

As always, Bob, if money weren't a problem . . .

Grazie

johnmeyer wrote on 1/5/2008, 1:04 PM

Well, I'll try one more time.

Use the FFT3D plugin for AVISynth, and you won't have those problems.

CClub wrote on 1/5/2008, 2:06 PM

John,
This is why some of us must drive you crazy: I'm the type that wants to download a Vegas plugin, it installs, and an icon pops up on the FX options. I'd rather pay for a plugin and it holds my hand like that than work through 6 software downloads/imports/exports that are free. Not that I have money to burn, it's more like I don't have excess brain cells to burn, likely due to excessive college life in the 80's.

I went to the avisynth.org website and the doom9.net site, and there are so many options I start to shake. I've never used avisynth... when I search around the site, it seems that VirtualDub is an offshoot of avisynth (?), so I guess I've installed it when I've used the DeShaker package you put together. Is there a GUI and a way to add the FFT3D plugin to that to give your recommendation a shot? I'm assuming that you try the denoiser plugin directly on an avi file and then after it's "de-noised" by the FFT3D plugin, you bring import it into Vegas? I apologize for the basic questions... I very much appreciate how you transition things into layman's terms.

Grazie wrote on 1/6/2008, 1:32 AM

John, you are a very patient man indeed.

CC, I agree with you. John created the DeShake suite to make it so easy for a less than s/w capable person like I. It just set itself up and away I went. THANK YOU John Meyer!

When I see the complexity of some of the majorly powerful software menus I get quite depressed, like a kid looking longingly into the sweetshop . . . . . .

Oh well . ..

G

johnmeyer wrote on 1/6/2008, 10:43 PM

AVISynth is for geeks, that's for sure. I wish there was a way to make it more accessible, and it would be a HUGE deal if there was some way to make some of the AVISynth plugins available within Vegas. Satish started down this road many years ago with "WAX" which was able to let you use some VirtualDub plugins within Vegas. However, WAX was (and is) pretty geeky, and getting the VD plugins to work within Vegas was not an easy task.

So, for now, if you don't fee comfortable with AVISynth, then use the Mike Crash implementation of one of the VirtualDub plugins, or buy the Neat Video denoiser. Just don't "turn up" the controls too high, and I think you'll be quite happy with the results most of the time.