Example: Rotoscoping

In the following example, a clip shows a man and a woman climbing on a motorcycle. The word "Suzuki" is partially visible on the motorcycle's gas tank. You want to temporarily remove the word Suzuki, then gradually make it reappear.

Note: The purpose of this example is to illustrate one of the many ways of performing a common rotoscoping task.

Step 1: Selecting the Logo

Load the footage into a Paint operator. Make sure you are at the first frame, then draw a Polygon selection that covers the word Suzuki. To make the selection blend in, feather the edges slightly.

Step 2: Blending the Logo into the Image

Use a combination of blurs and color correction to make the logo impossible to recognize and blend it with the rest of the image. First, blur the selection using two different blurs: a Gaussian Blur and an unconstrained Box Blur (horizontal radius only). By blurring the logo, the colors become muddy. To fix this, apply a Balance color correction to bring vivid color back into the blurred logo.

Step 3: Keyframing the Blurred Logo

Here you want to make the logo slowly reappear. You can do this by animating the blur effects (with linear interpolation) so that their values gradually return to zero over the course of the clip.

First, make sure the Animate button is on. Then, extend the duration for all objects to the last frame of the clip. Finally, at the last frame, set the effects values back to zero for each effect.

Step 4: Tracking the Logo

Now track the position of the logo as the motorcycle shifts position. You could do this manually, but the Tracker is much faster. By tracking the selection to the logo, you ensure that the blurs cover the logo completely and move as the logo moves.

Step 5: Play the Clip

Play the clip to see the effect.