Apple Final Cut Pro 5 - Manual (Page 1192)

Chapter 19 Keying, Mattes, and Masks 405
II
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.
Before changing the
location of the first point After changing the location
of the first point
The matte, with rounded
corners