Instruction Manual

Chapter 13 Keying 488
Keyer lter
Keyer lter overview
The Keyer lter is intended for subjects shot in front of a blue screen or green screen. However,
this lter can also be used to pull chroma keys from any range of color within a shot. The keyed
portions of the image are rendered transparent, allowing background images to show through.
You apply a Keyer lter like any other lter in Motion—via the Library or the Add Filter pop-up
menu in the toolbar. For more information about applying lters, see Apply and remove lters on
page 742.
Important: When combining masks with a keying lter, make sure the masks you use to crop the
keyed image are applied to the same image layer as the keying lter itself. Also, apply masks after
you apply a keying lter.
Automatic versus manual keying
At its default settings, the Keyer lter attempts to work as automatically as possible. When you
apply the Keyer lter to an object, Motion analyzes the visible frame in the Canvas to detect a
dominant color such as a green or blue background. The dominant color becomes the initial
sample that generates the tolerance, or core transparency, of the underlying key; this key is
rendered as transparent in your composite.
However, you can override the automatic initial color sampling to key any color. You do this by
setting the Strength parameter to 0, then using the Sample Color tool to draw a selection box
over the region containing the color you want to key.
Keyer lter controls
After you apply the Keyer lter to a video or image layer in your project, you can modify and
rene the keying parameters in the Filters Inspector or HUD. This section explains the operation
of the tools and parameter controls found in the Keyer section of the Filters Inspector.
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