Apple Final Cut Pro X (10.0.9) - Manual (Page 338)

Chapter 12 Keying and compositing 338
4 To help fine-tune the key, use the View options:
Original
(unprocessed
foreground)
Matte (foreground-based
alpha signal created
by the keyer)
The name of the currently
selected View button
Composite
(foreground combined
with background)
•
Composite: Shows the final composited image, with the keyed foreground subject over the
background clip. This is the default view.
•
Matte: Shows the grayscale matte, or alpha channel, that’s being generated by the keying
operation. White areas are solid (the foreground video is opaque), black areas are transparent
(the foreground is not seen at all), and varying shades of gray indicate varying levels
of transparency (the background video can be seen mixed with the foreground video).
Viewing the matte makes it easier to spot unwanted holes in the key or areas that aren’t
transparent enough.
•
Original: Shows the original, unkeyed foreground image.
5 To further refine the matte, use the following controls:
•
Fill Holes: Increasing this parameter value adds solidity to regions of marginal transparency
within a key. This control is useful when you’re satisfied with the edges of your key, but you
have unwanted holes in the interior that you can’t eliminate via the Strength parameter
without ruining your edges.
•
Edge Distance: Lets you adjust how close to the edge of your keyed subject the effect of the Fill
Holes parameter gets. Reducing this parameter value brings the filled area of the matte closer
to the edge of the subject, sacrificing translucency at the edges. Raising this parameter value
pushes the filled area of the matte farther from the edge. Too much edge distance can result
in unwanted translucency within parts of the subject that should be solid.
6 To suppress any of the background color that is appearing (spilling) on the foreground image,
adjust the Spill Level control.
7 To reverse the keying operation, retaining the background color and removing the foreground
image, select Invert.
8 To mix the keyed effect with the unkeyed effect, adjust the Mix control.
For information about making advanced chroma key adjustments, see the following instructions.