Color Spill

Color Spill

If Keylight (or another tool) is not doing spill suppression
as you would like, the following alternatives are available:
Effect > Keying > Spill Suppressor uses a simple channel
multiplication formula to pull the background color out of
the foreground pixels. All you need to do is select a sample
from the background color (you can sample the Keylight
Screen Colour selection) and leave the setting at 100%.
Effect > Color Correction > Hue/Saturation is the option
I use most nowadays. It takes practice, which can easily be
done; try the following on a source blue or green screen
image (no key—just so you can see everything):
1. Apply Effect > Color > Hue/Saturation.
2. Under Channel Control, choose your primary (Greens
or Blues—plural for some reason).
3. Lower the Saturation value for that channel to zero.
4. Use the Channel Range sliders to eliminate the key
color.
5. Boost Saturation to 100% to see if other colors are being
desaturated that should be kept; adjust accordingly.
6. Now with the key applied, try some mixture of the following
to eliminate spill:
. Lower Saturation (still on the individual color
channel).
. Shift Hue between about 30 and 90 degrees
to either direction (depending on your target
background).
Some combination of desaturation and hue shift with a
carefully targeted range usually does the trick; the worst
that will happen is that other color artifacts will appear,