[HELP] Trying to remove VHS dropout (comet tails)

[HELP] Trying to remove VHS dropout (comet tails) - Printable Version

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Trying to remove VHS dropout (comet tails) - Miranda - 03.10.2024

I've already used KillerSpots in Vapoursynth which removed a lot of the spots, but not all.

For a second pass, I have also tried switching over to Avisynth and using the additional settings in DeSpot, but I can't seem to get it to remove the remaining spots.

Any suggestions?

Sample clip

There is also some additional noise on the whole video frames which I am unable to remove - it looks like a strange moiré pattern?

RE: Trying to remove VHS dropout (comet tails) - Selur - 03.10.2024

Masked Spotless with high (i.e. 5 or 6) temporal radius?
For example:

## Starting applying 'EdgeMask (Prewitt)' masked filtering for vsSpotLess
clipMask = clip
clipMask = core.std.Prewitt(clip=clipMask)
clipMask = core.std.Maximum(clipMask)
clipMask = core.std.ShufflePlanes(clips=[clipMask], planes=[0], colorfamily=vs.GRAY)
clipFiltered = clip
# Spot removal using SpotLess
clipFiltered = SpotLess.SpotLess(clip=clipFiltered, radT=6, pel=1, smoother="zsmooth")
clipMask = core.resize.Bicubic(clip=clipMask, format=vs.YUV422P10, range_s="limited", dither_type="error_diffusion")
clip = core.std.MaskedMerge(clip, clipFiltered, clipMask) # PrewittEdgeMask
## Finished applying 'PrewittEdgeMask' masked filtering for vsSpotLess

Probably would be better to apply something like this on the source before applying Despot and you might have to try different masks and settings. Smile

Cu Selur

RE: Trying to remove VHS dropout (comet tails) - Miranda - 03.10.2024

I just tried running the original ProRes 422HQ file through AVIsynth to re-try the DeSpot filter but now I get a preview error - ConvertToYV12 - only 8 bit sources allowed.

Do I need to convert to standard ProRes 422 for this to work?

RE: Trying to remove VHS dropout (comet tails) - Selur - 03.10.2024

Quote:I just tried running the original ProRes 422HQ file through AVIsynth to re-try the DeSpot

not what I suggested,..

Quote:now I get a preview error - ConvertToYV12 - only 8 bit sources allowed.

Do I need to convert to standard ProRes 422 for this to work?

Strange, according to the source code Hybrid should be aware that Avisynths DeSpot requires YV12@8bit.
Also tried it and it works fine here:

LWLibavVideoSource("G:\TestClips&Co\files\ProRes\Test Patterns Resolve 422 HQ 10-bit.mov",cache=false,dr=true,format="YUV422P10", prefer_hw=0,repeat=true)
# current resolution: 720x576
# despotting using DeSpot
# Converting from 10 to 8bit for DeSpot
ConvertBits(8)
ConvertToYV12(interlaced=false)
DeSpot(median=false,interlaced=false)

Hybrid automatically converted to 8bit and YV12.

Cu Selur

RE: Trying to remove VHS dropout (comet tails) - Miranda - 03.10.2024

Also, where do I find EdgeMask?

RE: Trying to remove VHS dropout (comet tails) - Selur - 03.10.2024

You enable the Masking controls (Filtering->Masking->Ui->Show 'Masked'-controls) and then the controls are next to Spotless.

Cu Selur