2011

To change the color of a tracker:
1 In the File Browser, click the Tracker that corresponds to the tracker you
want to change.
2 Under Display, click the color pot next to Color.
The color picker appears.
3 Select a new color that can be easily seen in the footage and click Set.
The tracker changes color.
How the Tracker Works
The Tracker first tracks motion of the reference feature(s), then applies or
inverts that motion, depending on if you are tracking or stabilizing.
Once you have set up your trackers, the analysis can begin. This is how the
Tracker analyzes and remembers the motion of the reference feature:
■ The Tracker stores the position of the reference box on frame 1.
■ The Tracker advances to the next frame and positions the tracker box in
the same place as in the previous frame.
■ It searches the tracker box for an area that matches the contents of the
reference box. The Tracker uses luma cues (white versus black) and shape
cues to determine what is a match.
■ Once it finds a match, the Tracker uses the location of the match to move
the center of the tracker box over the center of the match. This change in
position is stored as an X and Y shift value.
■ On the next frame, and on all future frames, the Tracker gets a little smarter
about where it positions the tracker box. It extrapolates the likely position
of the reference feature based on the amount and direction of the motion
that occurred between the last two frames. The Tracker makes an educated
guess of where the feature may be, based on past matches.
NOTE This means the Tracker works best when the motion of the reference
feature is regular and does not suddenly or erratically change direction or
speed.
■ Once the Tracker has analyzed the motion of the reference feature, and
stored it as Shift values for each frame, it copies the motion of the reference
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