Help removing DVD rainbow artifacts

[Naltrex]

Hello! I need a bit of help here. I'm not really an expert in video restoration, and I'm trying to find a way to remove annoying rainbow-like artifacts. I'm not sure what they're called.

This video is sourced from a DVD - I've attached a small sample. It's really noticeable, for example, in the scene with a close up of the girl, in her hair, or in the scene with Freddie Mercury's sillhouette, in the digital computer drawings.

I've tried various methods I thought would work, with no avail. I'd really appreciate it if someone could point me in the right direction. Cheers

[davexnet]

What specific methods did you try?

[s-mp]

^

not every rainbowing artefact is the same. it would be helpful to know what have you tried before

[johnmeyer]

I didn't see much rainbowing in that clip, except near the beginning in the girl's hair. If it were me, I'd just live with it.

[jagabo]

How's this?

[Selur]

Nice, what did you use?
(fft3dfilter on chroma only with sigma=20, would also work but smooth chroma quite a bit)

[jagabo]

The chroma blurring was done with BinomialBlur and a SMDegrain. I used a mask to apply the blurring only near chroma/luma edges.

Mpeg2Source(...)
src = last

emask = Overlay(UtoY().mt_edge(thy1=4,thy2=4), VtoY().mt_edge(thy1=4,thy2=4), mode="add").mt_expand().PointResize(width, height)
emask = Overlay(emask, mt_edge(thy1=8,thy2=8).mt_expand(), mode="multiply").mt_expand().BinomialBlur(5.0)
bchroma = src.BinomialBlur(0.0, 5.0, 2, 3, 3).SMDegrain(tr=5, thSAD=5000, refinemotion=true, contrasharp=false, PreFilter=4, mode=0, truemotion=true, plane=3, chroma=false)
Overlay(last, bchroma, mask=emask)

MergeChroma(src, last)

The strong SMDegrain settings may cause some chroma ghosting.

Note that I treated the video as progressive though it contains a few interlaced shots (most of which were b/w). It may need to be modified to work properly with interlaced shots.

[s-mp]

what DVD has this video been sourced from?

[Selur]

Nice.
I attached how QTGMC+maskedFFT3DFilter and QTGMC+maskedFFT3DFilter+SpotLess+MCTemoralDenoise look like.

[s-mp]

Is there any way to disable that grain freezing on QTGMC? The denoising makes the video look kinda dull, and grain freezing is really distracting. Otherwise it's a nice output must I say.

[Selur]

Sure, there are tons of options in qtgmc to lower the denoising.

[jagabo]

http://avisynth.nl/index.php/QTGMC#Noise_Bypass_.2F_Denoising
http://avisynth.nl/index.php/QTGMC#Source_Match_.2F_Lossless

These can reduce the effectiveness of the antialiasing and buzz reduction.

[s-mp]

oh thanks these definitely will be helpful in my qtgmc usage. for a long time i'd just use veryfast to buypass denoising