Create a Tracking Blur in NewTek SpeedEDIT

In Timeline view, select the clip to which the blur must be applied and duplicate it (C followed by V). Place the new video clip on the Timeline below the original. This will become the blur clip. Check the overlay box when the blur clip is selected, or press the Y key. This will enable transparency on the blur clip so we can see the original unaltered video behind its cropped edges.

With the blur clip selected in the Timeline, switch SpeedEDIT’s other pane to Control Tree view. Expand the Blur menu and click its "enable" checkbox. Next, raise the blur X and Y values high enough to obscure whatever needs to be hidden by the tracking blur. In this example, it’s a logo on a t-shirt; a blur of 5 in each direction does the trick. Select the Positioning tab in the Control Tree view to see the changes made by the blur. These will also be visible in real time in the Output window and FireWire preview if they’re in use.

Scrub the clip to its first frame in the Control Tree Layout View using the timeline slider at the top of the frame. Expand the cropping menu in the Control Tree (click the +) and drag the Crop Left, Right, Top and Bottom values until you have cropped down to just the area of the clip that needs to be obscured. The Output window will show the composite of the two clips, while the positioner shows only the blur clip. Now click the black circles next to each of the four crop values in the Control Tree. These buttons will switch to white, indicating that keyframes have been generated.

Expand the edges menu in the Control Tree. Setting a Smooth percentage value around 5 percent will soften the edge of the blur effect, making it less distracting.

Now scrub the clip to its last frame in the Control Tree Layout View and repeat the process of setting the crop edges. Each setting will automatically keyframe this time.

Scrub through the clip, watching the blur track over the original video in the Output window. Each time the subject to be obscured changes direction or speed within the frame another group of cropping keyframes must be set. Depending on the complexity of motion in the scene, setting the additional keyframes may take a few seconds, or a few minutes. In this example, where a person turns into view and then walks out of frame, a total of five keyframes were needed. You can also view the keyframes and crop settings in the Control Tree’s Spline view.

Even on a modestly powered system, SpeedEDIT will have no problem creating and adjusting this effect in real time. To make things more manageable and keep the blur layer properly synched to the background layer while editing, it’s a good idea to select (click) both video layers, as well as any synchronized auto layer, and click the Sub Project button to merge them into a single clip on the timeline. If any changes need to be made later, it’s a simple task to drill into or expand the sub project.

Bill Mills
Owner
Corinthian Media Services

Bill and Dawn Mills founded Corinthian Media Services in 1992. The company produces multimedia content and has specialized in Internet and print publications related to the sport of paintball; they have managed the sport’s original Web site since 1995 and Webcasting long-form video programming since 1997.

Bill says Keep in Mind…
SpeedEDIT is one great resolution-independent NLE, but some features need to be uncovered before you can tap the software’s full potential. For example, it’s easy to overlook some of Control Tree’s best features because they aren’t obvious. There is, however, plenty of power there for color correction, compositing and general tweaking. All of these adjustments are also key-frameable. To compensate for lighting changes, you can even go so far as making Chromakey color or tolerance change over time with your clip.

Corinthian Media Services
www.corin.com
323 Gephart St. SW
Palm Bay, FL 32908
ph. 321-724-4466
http://www.corin.com/bill/bfeedback.shtml