Cleaning head switching noise in analog video

[medipal]

Working on the removal/reduction of the head switching noise bar at the bottom of digitally captured analog videos.

This might not make it into the final "WinDV-style app" I am working on; it takes a bit long (~20 seconds of work on a decent laptop per second of footage).

So far it works, and retains the footage losslessly, except for the portion that is changed of course.

It's done by temporal video inpainting, not just cropping or blurring the line away. It looks at motion and information in neighboring frames, then tries to reconstruct the damaged strip using surrounding frames as references. Only processing the affected bottom strip part not the whole image


[Attachment 93966 - Click to enlarge]

[johnmeyer]

I'll be interested in seeing your results on fast-moving footage, with both bright and dark at the bottom of the frame. Rather than crop, which involves resizing, I usually just overlay a few pixels of black along the bottom. You seldom notice it.

[Selur]

spotless limitted to the bottom xy lines often can fix such stuff, assuming surounding frames have enough data,...

[johnmeyer]

spotless limitted to the bottom xy lines often can fix such stuff, assuming surounding frames have enough data,...

Is that true? Is this in the Spotless documentation, or has anyone posted such code?

I know that Spotless has to use data from adjacent areas to fill the spots it identifies, but I didn't know it could be restricted ("limited") so just the bottom "xy lines," although maybe that has to be done with a mask. I also didn't know that you could trick it into thinking that all the bottom lines are one big spot that has to be replaced.

It would be interesting to see a result.

[Selur]

that is based on my experience.
No you simply:
a. crop your image to i.e. the bottom 16 lines
b. apply SpotLess i.e. with temporal radius 3
c. replace the 16 bottom lines of the input with the filtered onces
EdgeFixer, Bore and similar filters might also be worth a try.

Cu Selur

[themaster1]

..or you can physically turn the pcb (stator below) on top of the drum, depending on the model you have to actually remove the head switching line almost completely
What am i talking about ? See HERE 42 min mark

[johnmeyer]

Your timecode was set for only 18 seconds into the video. Here is a link which takes you straight to where he shows how to make an adjustment for head switching noise:

Head Switching Noise Adjustment