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View Full Version : a Special Scratch Removal Filter


Maximus_G
16th January 2004, 07:55
Hello, everyone,

i've posted this at virtualdib.everwicked.com, but unfortunately that thread received little or no attention at all.

We are now working on some WWII footage ("Memory" project, http://www.translate.ru/url/tran_url.asp?l...ransliterate=on )

The big problem that we have faced is the quality of the material - there are so many scratches... and the only way to fight them that i've found is to use these plugins:

1. http://i4004.0catch.com/ctmedian.htm
2. http://bag.hotmail.ru/despot/despot.dhtml
3. http://observatory.playland.ru/article21_a...icle_24_1.phtml

The main problem with these filters is:

1. They produce artifacts, more or less.

2. They have a big constraint - a fast-moving picture is treated as noise/scratches to be removed. If we raise the threshold parameters, than we just cannot detect scrathes effectively. So these plugins work well only when the picture is not shaky and doesn't contain too much motion. Needless to say that aviation footage is both shaky and fast.

The question is - are there any other scratch removal filters/plugins, equally or more effective as those mentioned, including plugins for programs other than VDub and AviSynth?


On the Doom9.org forum i've found information on project "Brava" http://brava.ina.fr/index.en.html
It's even more than we need, and they have produced the plugins for Premiere, but as we presume, those plugins cannot be obtained.
Maybe there's something like that?

If no, than we'd like to discuss the aspects of a special filter development, involving object recognition and restoration techniques.

---

SO, in 2 words: :)

If we use an image recognition technique, the filter would be able to distinguish dust and scratches from the main material and temporal noise just the way WE (humans) do - and that would be the best way to localize scrathes properly, and treat'em as needed. Furthermore, using motion map, we could restore lost parts by transforming them from previous/next frames.

Do such filters exist? If no, are they needed by the community?



Best regards,
Maximus_G

morsa
16th January 2004, 09:18
Yes they are needed by the community, and will always be welcome ;)
Also an improved deconvolution filter could be needed and a frame synthetizer as well to repair lost frames.

Maximus_G
19th January 2004, 04:35
Very nice.
It's just a little bit strange to get no feedback on this topic at such a forum.

morsa
19th January 2004, 05:48
Donīt worry itīs always the same.
Most of the people here is interested about ripping DVDs and restoring old VHS and Laserdisc recordings to convert them to Mpeg2 or 4.
The same happened to me the first time I proposed to port a Deconvolution filter from the Gimp project, nobody payed attention.
Finally thanks to Fcchandler (Vdub forum admin)I could get a port, and Emiliano improved it to make it faster.Today it is used by many people out there.
If you are interested about developing the filters youīve mentioned, I would be glad to give you all the info I can, tips, and posible solutions, although Iīm not a programmer.
Everybody here will help you, I guess, when the time comes to ask for specific code, optimizations, routines, etc.

MfA
19th January 2004, 06:06
Well it's only usefull for a very select crowd ... and noone yet seems to have felt the itch to solve the problem, non motion compensated spatio-temporal median filters are only of limited use as you have noticed, so there isnt much to say. Im sure there will be a couple of people interested in using it eventually if you want to develop such a filter.

Maybe you can find a local university with an image processing lab which is willing to partner with you to develop the software.

Maximus_G
19th January 2004, 08:00
I got it, thanks men :)

Fizick
21st January 2004, 23:23
You may also try my DeScratch filter,
and General Motion Compensation (genmotion) filter with DeSpot,
But for fast object, local motion must be compensated too,
however I found only one motion estimation filter for VirtulDub:
http://www.compression.ru/video/motion_estimation/index_en.html

I have some info for film restoration, and try implement it.

FredThompson
26th January 2004, 11:51
There's also SpotRemover for VirtualDub and a bunch of nice articles about scratch removal over at neuron2's site.