Motion Tracking in After Effects

In Aftereffects, import a video clip and place it in a composition. Ideally the composition will match the frame rate of the video.

1. Open up the "tracker" palette.

2. Click on "Track Motion"

3. Drag the inner region to a high contrast area on the moving object that will stay consistent throughout the the clip.

4. Adjust the inner region so it includes a trackable high contrast detail and some space around it. The outer region defines the hunting area - where it will hunt around in the next frame to find a simlar looking inner region.. So make the outer region large enough so the thing you are tracking will not escape. If you are traking Rotation or Scale you will have multiple trackers to position.

5. Press the Triangle play button in the Tracker palette to begin tracking.

6. If you loose the object, press esc to stop tracking, go to the frame where you lost it, reposition the tracker, then continue from where you left off with step 5 above.

To Apply the tracked motion to another object.

1. At the top, click on the Composition Tab (you were tracking in the layer not the composition)

2. Create an object to apply the motion to.

3. From the Motion Source dropdown in the Tracker Pallette - select the clip you have been tracking.
4. Click on Edit Target (see below) in the Motion Tracker Palette, make sure that you have the correct target object selected.

4. Click Apply in the Tracker Palette. Say yes to x and y. Now your target object should have keyframes on it from the tracker.

You may be interested in using multiple trackers, then deforming an image that is pinned to these points in 2D space. See this example and this tutorial.
Joshua Mosley 2010