Ghosting / Oversharpening Artifact Removal

[oo_void]

Long time avisynth user. I got sucked into working on a personal project to restore some old videos. I know that most won't see it, but I do and it's driving me nuts. All of these so-called "Remastered" videos have been run through, what appears to be, some sort of analog sharpening filter creating some really nasty ghosting. I've tried playing with both Ghostbuster and vsLGhost, but I don't have experience in dealing with these types of artifacts and can't manage to get good results out of either of them. If there's anyone out there who's dealt with Ghosting before who has any tips. 100 frame sample clip should be attached (DNXHR HQ codec).

[Selur]

I would suggest trying de-halo filters.
DeHalo_alpha(clipFiltered, brightstr=1.40): https://imgsli.com/MTM4MTc3 still need tweaking, but seems like the right approach.
(FineDeHalo and others probably also work)

Cu Selur

[oo_void]

I would suggest trying de-halo filters.
DeHalo_alpha(clipFiltered, brightstr=1.40): https://imgsli.com/MTM4MTc3 still need tweaking, but seems like the right approach.
(FineDeHalo and others probably also work)

Cu Selur

Perfect recommendation. It seems to be working. Getting the best results with ...

video = video.DeHalo_Alpha(rx=2, ry=1, darkstr=1.4, brightstr=1.4, lowsens=50, highsens=60, ss=2)

I'll play more tomorrow with fresh eyes and make sure I'm not nuking the quality.

[themaster1]

One of the best scripts for deghosting i came accross in recent years is this one here: http://www.digitalfaq.com/forum/video-restore/10260-ghost-removal-filters.html#post66112

[jagabo]

You can also try FineDehalo(). It's a variation of Dehalo_alpha() that limits the effect to the strongest halos. It helps retain detail in other parts of the picture. It also lets you get away with stronger settings for the halo removal.

FineDeHalo(rx=4.0, ry=1.0, darkstr=1.0, brightstr=1.0)

Or you can make your own edge mask to limit the dehaloing with dehalo_alpha()

emask = mt_edge(...)
Overlay(last, dehalo_alhpha(...), mask=emask)

Also be aware that as faces get smaller halo reduction may make them look like mannequins. Very artificial looking.

[Selur]

okay, I thought FineDeHalo rx was restricted to 1-3 (http://avisynth.nl/index.php/FineDehalo) => just checked neither FineDeHalo nor DeHalo_Alpha need to be restricted to 1-3 from the looks of it.

[jagabo]

dehalo_alpha works best with smaller halos. As rx and ry increase you get more and more damage to the rest of the picture. So 1-3 or thereabouts is a practical limit. With wider halos (eg. rx~=6 for VHS) I find it usually helps to downscale, dehalo with a lower radius, then upscale back to the original size.

[Selur]

Interesting, good to know. Thanks for the info.

[oo_void]

@jagabo Thanks for the tip on FineDehalo. That also led to finding info on how to use FineDehalo2 correctly to address the dark shadows. Ended up with the following processing --

video = video.FineDehalo2(hconv = "-1 -1 6 6 16 6 6 -1 -1", vconv = "-1 -1 1 1 16 1 1 -1 -1")
video = video.FineDehalo(rx=2.0, ry=1, thmi=16, thma=160, thlimi=50, thlima=100, darkstr=1.2, brightstr=1.4, showmask=0, contra=0.0, excl=false)

There's still the slightest hint of a dark halo, but it's pretty darn good. I'm also pretty sure that what looks like a drop in quality is actually some of the sharpness ringing being removed. I also added a bit of CAS afterward in the sample just for good measure.

https://imgsli.com/MTM4MzA2

[oo_void]

One last question, where's the best place to run Deghosting, the original content is PAL converted to interlaced NTSC. I'm doing a QTGMC temporal bob with noise preservation enabled, and then an SRestore to get it back to 25fps. After that, it's a bit of sharpening and gradient removal. Should I Deghost before or after the frame rate conversion, or after everything else? I'd test myself, but as with all "great" (read bloated) Avisynth scripts, my QTGMC command has got me at about 1fps on my poor laptop making it hard to run comparisons.

[jagabo]

Probably dehalo before or after frame rate conversion (whichever works best) and before the other filters.

[DMFOREVER98]

Everything Counts and Condemnation masterpieces from the albums Construction Time Again and Songs of Faith and Devotion I would like to see the results of those videos.

[oo_void]

Everything Counts and Condemnation masterpieces from the albums Construction Time Again and Songs of Faith and Devotion I would like to see the results of those videos.

Hard to officially distribute, but I've got 30 GB of content done and processed for 1280x720 along with re-mastered, 24-bit FLAC audio. Upscaling to 1080 didn't really add more plus, the upscale processing in most TVs nowadays does a pretty good job with the last step. Rendering an LD capture of the 1984 concert in Hamburg as I type.