After editing a crowd scene, you've discovered there's one man in the shot who didn't sign an image release.  To avoid possible legal trouble, you decide to solve the problem by blurring his face - the classic "witness protection"  effect.  However, the shot is shaky because your budget didn't include a tripod, nor any motion tracking software.  So, here's how to use Final Cut Pro HD to track the man's face and blur it out, without having to use any third-party products, and without having to set a single keyframe.

1. Edit the crowd clip into the V1 track of a sequence.  For the purposes of this tutorial, I will call this sequence "crowd with matte nest."

2. To make the oval that will isolate the man's face, create a title with a bullet point (Option-8).  Its color is not important.  Superimpose the title onto the V2 track above the crowd segment, and adjust the title's Size and Origin to position the bullet over the man's face.

Clip courtesy of Digital Juice, Inc.

3. To soften the edges of the oval, apply a Gaussian Blur onto the title, and set its Radius to something like 20.

4. Modify the frame size of this sequence by choosing Sequence > Settings (Command-zero), set its Aspect Ratio to Custom, and its height to 1000 pixels.

5. Double-click the crowd segment to load its settings into the Viewer.  Here, we will need to flip over the image and move it to one side of the frame.  If you want to be exact, set Rotation to 180 and Center to (0, 260) so that the image is upside-down and at the bottom of the frame.

6. Double-click the title segment to load its settings into the Viewer.  Here, we will move the title to the opposite side of the frame.  Positioning it higher so that its Center is around (0, -370) should work.

7. Create a new sequence.  For the purposes of this tutorial, I will call this sequence "crowd tracking parent." Open this new sequence.

8. From the Browser window, drag the original crowd with matte nest into the V2 track of the crowd tracking parent.

9. Option-double-click the nest in the timeline to load its settings into the Viewer.  Make sure its Scale is set to 100.

10. With the Canvas set to Image+Wireframe, Shift-drag the image upward so that you can see the man's upside-down face.

11. Hit the Home key to move the playhead to the beginning of the sequence.

12. Apply Video Filters > Video > Image Stabilizer.  In the Filters tab, adjust the Image Stabilizer's Center and Scan Range around a sharp, high contrast, unobscured spot on the man's face, such as his nose.

13. With the Canvas set to Image+Wireframe, Shift-drag the image downward to move the man off the screen and reveal only the blurry dot.  If you want to be exact, switch to the nest's Motion tab, and set its Center to (0, 260).  Since the dot is nested with the shaky video, the Image Stabilizer will make it move in the same way as the man's face.

14. Edit the original crowd clip into the V1 and V3 tracks so that the nest is sandwiched between them in the timeline.  Delete any duplicate audio segments, if any.

15. Apply a Gaussian Blur onto the V3 segment, and set its Radius to something like 15.

16. Right-click or Control-click the V3 segment, and choose Composite Mode > Travel Matte Alpha.  You may have to render before Final Cut Pro will show the blurry dot.

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Christopher Phrommayon is an Avid- and Apple-certified instructor whose independent audio and video productions have been seen internationally.  Chris has contributed to publications such as "Final Cut Pro on the Spot" and "Videography" Magazine, and is co-author of "Avid Xpress Pro and DV on the Spot."  Recent speaking engagements include the Avid Government Training Symposium, the Final Cut Pro to the Max tour, the DigitalMediaDC Conference, and the NAB Post-Production World Conference.

Chris teaches Avid Media Composer, Final Cut Pro, DVD Studio Pro, Shake, Adobe After Effects, Adobe Photoshop, Adobe Premiere, and Boris Red for Future Media Concepts in Boston.