• Adobe After Effects

  Green screen edge ripple problem

  Posted by Bibbles on July 12, 2005 at 5:29 am

  Trying to key on green screen but there is a ripple effect around the head of the person. Original footage is dv. Brought in the avi as uncompressed with no fields-60fps. Am I missing something really simple?
  Thanks,

  Arthur Vibert replied 20 years, 10 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Arthur Vibert

  July 14, 2005 at 6:05 pm

  DV, as you’ve discovereed, has a lot of compression artifacts that can cause the problem you are describing. One technique for reducing the effect of the compression artifacts is to convert your footage from RGB to YUV using Channel Combiner. Check repeat edge pixels and using Channel Blur apply a small amount of blur to the green and blue channels. You can solo each channel by pressing Alt+2/Option+2 or Alt+3/Option+3. Focus on a particularly noisy area of the frame (in your case probably around your subject’s hair) and apply just enough blur to reduce the artifacting. Apply Channel Combiner one more time to return from YUV to RGB. This should reduce your chatter.

  I highly recommend “After Effects 6.5 Studio Techniques” by Mark Christiansen which is where I got this technique. It has tons of great information about compositing with AE.

  Arthur Vibert

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