Zebra lines on captured footage...

[rur]

Is there anything that can be done in post to fix the "zebra lines" that have appeared on the background footage I filmed? It was an interview and the person is in focus but there are bad "black and white zebra lines" on the captured footage in FCE. Is it not a good idea to film with a patio screen in the background??

[24Peter]

Morie patterns (or whatever the french word is for the distortion of small repeating patterns in your footage.) http://www.physics.isu.edu/physdemos/waves/morie1.html

You definitely don't want to shoot with a patio screen behind your subject if there's any chance the screen will be within the focus plane (if it's far enough behind to not be in focus, you're OK - in fact, you can use a flexible pet screen to cut down on light entering through a door or window so as not to blow out your video as long as the screen won't be in focus.)

If you've already shot it, you'll need to blur out the background. Create a mask around your subject and apply gaussian blur to your background layer. But before you do that, check your footage on a progressive scan TV/monitor - the morie patterns may not be as bad as you thought. They look worse on interlaced TV's.