VHS constant horizontal line noise

[kodec]

Hi guys, is there a way / what is the way to remove a constant horizontal line similar to this one in the example under the Horizontal Video Line Drop Outs section in the link below:

http://canvasprintmaker.blogspot.com/2012/04/correcting-vhs-s-vhs-vhs-c-video8-and.html

Obvioulsy there is a way, but the guy didn't name the exact means to do it, except mentioning that there are motion compensated horizontal line filters out there. What I'd like to know is if it can be done via VirtualDub and its plugins, some interplation maybe? I am using otherwise brilliant NeatVideo a lot but it doesn't help here.

The home family VHS tape I came cross was compiled from various sessions recorded on various occasions over a long time span, probably from various dirty VCRs and / or camcorders and / or a scratched tape. Some of the footage from specific parts of the recording has such similar constant horizontal line noise. The line is always in the same horizontal position, a little lower than the one in the link example, the noise level is not constant. I will post my exact troubled example later when I get home.

[jagabo]

If the lines stay in the same location over several frames there's not a lot you can do about them. You can try interpolating from lines above and below with a delogo filter but you'll get other distortions -- maybe less objectionable. A sample will help.

[kodec]

Here it is, the raw huffy:

http://www.filedropper.com/vhs-test

The line is always like this, in the same location, just the width is fluctuating, sometimes it's thiner, sometimes wider. Or there is no line at all, as seen in the example after the jump to a new scene. The duration of a line is not just frames, it can be tens of minutes, depending on how long the scene cut is. The tape is 1:42 hrs long and you have the line in at least half the footage over various scenes. The guy who gave me the tape said there was a problem but I didn't expect this and I would love so much to fix it for his family. If it's worth a try even the smallest advice from you guys is much appreciated. The same if you think it's going on for too long to try anything meaningful without destroying the footage in general.

[johnmeyer]

I was faced with a vaguely similar challenge. Here is the before & after:



It took awhile to develop a script that worked, and I got some help. Here is the thread which describes the steps I went through:

Bad 1950s Kinescope - Hopeless?

In my video, the noise bars were in a different location on every single frame. Your don't move around a lot, but they do move around, so some sort of detection will be required. In my case, once I detected the location of the noise bar, I then had to change the exposure of that bar. In your case, you will want to blur the pixels with the video directly above or below the video. No matter what you do, this is going to leave a big blur spot across the video.

You can also just use Delogo inside of VirtualDub. Just set the mask to be large enough so that it extends to the top and bottom of whereever the tearing happens within a given section of video. Regardless of whether you use Delog, or whether you create a mask inside of AVISynth, this is more or less what the result is going to look like: