Which filter?

[Singh00]

Hey, I've got an mpeg recorded from tv with some pretty bad noise in it. I'm not sure exactly how to clean it up. I've tried dynamic noise reduction and 2d cleaner in virtualdub, but neither worked. Does anyone know which filter I can use with vitualdub, avisynth, something else? Here's a screenshot of what I'm dealing with. The dots jump around pretty fast, but stay localized to the bands that are evident. Also, the bands move up the screen, keeping the same distance from each other, and eventually appear out of the bottom again.

[bunyip]

Haven't tried it myself but the example is impressive..
Try the 'Spot Remover' filter here -> http://konstant.freeshell.org/

Let us know if it does the job.

[Singh00]

Thanks for the suggestion, but unfortunately spotremover did not work.

[Singh00]

Note: The jpeg doesnt really show the dots well. They are actually much sharper, and are pure white.

[guns1inger]

I am surprised that Spot Remover didn't work. The other filter that often works for me is Temporal Cleaner (read about here - includes download link http://www.undercut.org/articles/temporalfilter.html ), although this may be a big ask for it. It is the fastest quality noise remover I've found.

[jimmalenko]

Maybe convolution3D ?

[lordsmurf]

I've seen that error. THe dots may be too fast and too small for filters to catch. But good luck, and don't give up.

[Wilbert]

Did you try DeScratch and DeSpot?

http://bag.hotmail.ru/descratch/descratch.dhtml

http://bag.hotmail.ru/despot/despot.dhtml

[SatStorm]

I never manage to clear those dots like yours, without heavy filtering...
Deinterlace (unfolge), use "frame merger" at a higher value and deinterlace (folge) again.
That might help a bit...
All the other solutions I can think of, are "temporal" (time axis based) filters, that distorts a lot the motion...

[mpack]

I never manage to clear those dots like yours, without heavy filtering...

You wouldn't - most decent filters are of the "switching" type, ie. if the difference between the filter output and the input pixel is above a certain threshold then the filter switches itself out, restoring the unfiltered pixel. If you raise the threshold high enough to remove these high intensity spots then it will introduce a lot of distortion elsewhere in the picture...

All the other solutions I can think of, are "temporal" (time axis based) filters, that distorts a lot the motion...

Caught between a rock and a hard place... A good temporal filter would be of the switching type, hence it would not blur motion noticeably... but it would also not remove these spots, since the prediction errors would again be too high.

Incidentally, this doesn't look like normal analog noise to me. It looks like electrical interference, caused either by poor quality capture card electronics, or poor quality unshielded video cable passing close to some interference source.

[BSR]

Incidentally, this doesn't look like normal analog noise to me. It looks like electrical interference, caused either by poor quality capture card electronics, or poor quality unshielded video cable passing close to some interference source.

hmmm, looks like what I see on the TV when the vacuum is running. Very interesting noise pattern.

[SatStorm]

This kind of noise is electrical interference. That's for sure. I know about it, because 18 years ago, terrestrial "transmissions" with that kind of noise, use to be usual, when some local stations here in Hellas broadcast from analogue satellite feeds. Most of the reasons was stupid ones, like all the electrical interference of that kind.
MTV Europe use to transmit with such "noise" for more than a year here, when it had terrestrial distribution in Hellas.

Beause I have many tapes from that period, with rare music videos from late 80s early 90s, I had to deal with that kind of noise. I never manage to "clear" the picture from it, but I manage to make it look less, with the combination I suggested. And without move distortion (a typical problem that occurs with the Dynamic Noise Reduction filter at higher values, or the framemerger one... )

[LSchafroth]

Did you try DeScratch and DeSpot?

http://bag.hotmail.ru/descratch/descratch.dhtml

http://bag.hotmail.ru/despot/despot.dhtml

Is there a way to use these in Virtualdub? I'm not sure if I would prefer pulling all my teeth or use Avisynth?

LS

[Soopafresh]

Learning AviSynth is a path to enlightenment...


Post a <2mb clip up here and let's see if we can help