Effectively Removing Ringing and Haloing?

[Seraphic-]

Hi, just wanted to get an general idea on this. How possible is it to remove ringing and haloing from video without too much damage to the underlining video's overall image quality? Does the removal process introduce image softening and blurring or other negative affects? Basically, can it be done and still result in a high quality picture? Thanks.

[MadRat]

DeHalo_alpha seems to be the most popular. http://avisynth.org/mediawiki/DeHalo_alpha http://forum.doom9.org/showthread.php?t=102794

Some people like to use EdgeCleaner with DeHalo_alpha because it gets rid of compression noise around lines in cartoons. http://forum.doom9.org/showthread.php?p=1331229#post1331229

There's also HQDering which some people like. http://forum.doom9.org/showthread.php?p=1043583#post1043583

MCTemporalDenoise is supposed to do some of that kind of stuff but I've never tried it. http://avisynth.org/mediawiki/MCTemporalDenoise http://forum.doom9.org/showthread.php?t=139766

[Seraphic-]

Thanks for the information. I purchased hardware that does scaling, but it apparently "the scaling engine causes vertical halos (ringing)". So wanted to see if it is possible to "fix" with post processing. Some additional sharpening might also be needed.

[Didée]

Excuse my naivity, but what's the actual benefit of the hardware, if you need to "fix" it afterwards? Aiming for speed (?) - lost in postprocessing. Aiming for "quality"(?) - reduced by postprocessing.

Even if those halo removers are "quite good", none of them is "without issues". And they need time to do their calculations. Seems more feasable to use a resizer with no (or only little) ringing in the first place. And if you happen to particularly like a halo-remover or edge-cleaner that in itself happens to utilize EEDI2 or NNEDI2, then you could as well resize with NNEDI2 in the first place...

[cretindesalpes]

You have to watch for the oversmoothing artifacts introduced by halo removal. Below is a typical example :

Source :
http://img22.imageshack.us/img22/9449/ppp0010.th.png (http://img22.imageshack.us/img22/9449/ppp0010.png)

DeHalo_alpha :
http://img408.imageshack.us/img408/2277/ppp0011.th.png (http://img408.imageshack.us/img408/2277/ppp0011.png)

The effect is particularly visible on the shaded part of the landscape. Gradients are lost, line contrast is reduced and the drawing looks like made of flat strokes (but halos are gone).

[Seraphic-]

Excuse my naivity, but what's the actual benefit of the hardware, if you need to "fix" it afterwards? Aiming for speed (?) - lost in postprocessing. Aiming for "quality"(?) - reduced by postprocessing.

Even if those halo removers are "quite good", none of them is "without issues". And they need time to do their calculations. Seems more feasable to use a resizer with no (or only little) ringing in the first place. And if you happen to particularly like a halo-remover or edge-cleaner that in itself happens to utilize EEDI2 or NNEDI2, then you could as well resize with NNEDI2 in the first place...

Yeah, you are correct, you shouldn't need to fix it. It seems the issue can be improved with setting adjustments, but can never be removed completely from what I understand. It is also objective too, as it some people are annoyed more then others by it.

I needed an external hardware scaler to take 240p/480p stuff to 720p and this scaler does it (even goes to 1080p). It also supports 240p (for older generation hardware). My choices were XRGB3 or DVDO EDGE. I went with the EDGE as it seemed to be the better overall device. I was able to get a fantastic price for it, so I can always resell and make back what I paid if it doesn't work out. It arrives today, so I can mess around and see if the issues were made out to be worse then they really are.

[Seraphic-]

I've had this DVDO EDGE for awhile now and don't think it is going to work out. It processes the video too much and up-scaling using it does create haloing and ringing. Thought it would save time doing a hardware resize before capture then I could downsize to other resolutions as needed. However, now after seeing the results, looks like it would be far better to capture at native resolution then re-size using software filters or just leave as is.

Would like to ask though, if one was to use the right filters and script, is it possible to get a near perfect artifact free upscale (for example 480p to 720p/1080p and 720p to 1080p)?

[*.mp4 guy]

Would like to ask though, if one was to use the right filters and script, is it possible to get a near perfect artifact free upscale (for example 480p to 720p/1080p and 720p to 1080p)?

Only if lack of detail and or blurring can be ignored. Assuming an essentially perfect source, you can usually get away with a 2:1 upscale without it being obvious. 4:1 is basically impossible for natural content, though doable for cartoons/non-texture-dependent material.

However none of that answers the often debated question: should you upscale? Generally the answer to that question is: If you can avoid interpolation at any point, you should.

[Didée]

should you upscale? Generally the answer to that question is: If you can avoid interpolation at any point, you should.

True. But you won't avoid interpolation, because it's not very comfortable. With 1:1 pixel rendering, an SD DVD on a full-HD flat panel is darn small. :)

[*.mp4 guy]

True. But you won't avoid interpolation, because it's not very comfortable. With 1:1 pixel rendering, an SD DVD on a full-HD flat panel is darn small. :)

Yes, interpolation is often inevitable. What I was advocating was avoiding it whenever possible to minimize the number of times it is done, as every instance removes detail. Additionally anything you want to "archive" should never be interpolated, deinterlaced, denoised, or processed in any way. All of these operations will remove information you will never recover.