Black Halo from 2nd Generation VHS

[NoodleMaps]

I've got a 2nd Generation VHS tape that I am trying to convert. The original was destroyed in a flood years back. Everything on this copy looks creat except on some darker images where there are some bright lights going on. Causing a really black Halo effact around the bright light. Even hough the rest of the room is dark, the halo around the bright areas are even darker. Is there a technique for resoving this. Maybe a filter in Premiere, After Effects, of VDub, That I could easily say. that any values of black that are lower than this boost up to to equal whatever?

There's got to be something like that. I know levels can bring the rest of the blacks down to meet the halos levels but I just want to bring those levels up to meet the surroundings. Now I'm just rambling.....

Anyway. I hope someone can help me out.

Thanks

[junkmalle]

You can use a pair of Brightness/Contrast filters in VirtualDub. In the first, turn the brightness down until the dark areas and the dark halo are both black. In the second, undo what you did in the first.

For example, if the halo is intensity 0 and the other dark areas are intensity 10, decrease the overall intensity to -10. Both the halo and the dark areas will become 0. In the second step, you add 10 back to restore the dark areas. And since the halo couldn't get less than 0 in the first step both the dark areas and the halo will now be 10.

The other thing you can try is an Unsharpen Mask filter in VirtualDub. With a large diameter you can probably remove the halo. It will be slow and may have detrimental effects on the rest of the picture.

[NoodleMaps]

Thanks

I'm assuming this would also work if I was going though a Proc Amp and TBC before I captured as well. Watching on a wavefore would probably help as well, if I had one. But If I brought down the blacks to meet the level of black of the halo, would I be losing shadow detail. I'll give it a try when I get home from work tonight and find out.

But thanks for the suggestion. I've worked in Digital for so long now. I've completely forgotten the tricks of analog. I'm getting to old.

[junkmalle]

If I brought down the blacks to meet the level of black of the halo, would I be losing shadow detail.

Not if the "real" details aren't as dark as the halo. Say the rest of the picture runs from intensity 10 to 255 in brightness. Only the halo is at intensity 0. When the first filter darkens the image it will subtract 10 from each pixel. When it's done the halo will still be at 0 because the intensity values can't go less than 0. All the rest of the image will now vary from 0 to 245 (10 less than they were originally). In the second filter step you will add 10 to every pixel. The halo will become intensity 10 and all the rest of the pixels will be restored to their original values (10 to 255).

[NoodleMaps]

Thanks for your replies. I appreciated your time to answer.

[junkmalle]

Any chance you could post a sample frame? I'm curious...

[NoodleMaps]

Sure. Here is a before and after shot with your suggestions. I'm pretty sure I got what you were saying and I'm pretty happy with the results. Not the greatest footage to begin with. But didn't want to make it any worse than it was.




Thnaks again or your help.

[junkmalle]

Thanks for the sample pictures NoodleMaps. I see what you mean by the dark trails to the right of the spots on the guy's shirt. Looks like you've reduced them quite a bit without damaging the rest of the picture.