Sometimes, even with the finest adjustment of the brightness and transparency thresholds, the object photographed in front of the green screen will still be surrounded by a slightly green halo. This is usually caused by green light reflecting off the backdrop onto the object.
A clever way to remove this is to use 'Edge Nibble' Edge nibble in effect, removes a small number of pixels from any hard edges detected in the image. These hard edges correspond to the edges of the object being photographed.
You can vary how far into an edge you want to nibble by selecting a value between zero and four. A value of zero will cause edge nibble not to apply. A value of four will apply the maximum edge nibble.
