Apple Final Cut Express HD - Manual (Page 823)

Chapter 55 Keying, Mattes, and Masks 823
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3 Move the pointer to the Canvas (it turns into a crosshair pointer), then click to change
the location of the matte corner defined by Point 1.
4 Repeat steps 2 and 3 for the Point 2, Point 3, and Point 4 crosshair controls, until you’ve
created a box that crops out everything outside the blue screen surrounding the actor.
5 To round the four corners of the matte, adjust the Smoothing slider, if necessary.
6 You can also adjust the Choke and Feather sliders.
Before changing the
location of the first point After changing the location
of the first point
The matte, with rounded
corners