Remove scan lines from a filmed CRT

[Bob Peterson]

It will help to reduce the camera’s shutter speed.

[Dave Haynie]

I did something like that ages ago. If you’re stuck with that footage, here’s what you can try. Double the video layer. Now offset the bottom layer down by one scan line, if possible. You can try making the top layer transparent, or compositing as an add or a screen. Here’s an example:

This is actually a photo with simulated scan lines… I don’t have any analog televisions hooked up these days. So here’s a snap-shot from Vegas, with the two layers offset, using 50% transparency on the top layer:

And here’s the two set up as a composite set, in “screen” mode:

You could probably do a better job lining things up.. this was a quickie just to demonstrate the technique. And of course, if you have more than just the screen in your shot, you may have to use mask out the TV and do this in a few separate layers.

This is actually a crude attempt at building a simple comb filter, which is what modern televisions, particular digital televisions, do to de-interlace, remove scan lines, and filter out chroma, all in one operation.

-Dave