Using Matte Controls Operator

The Matte Controls operator allows you to shrink, erode, or blur the edges of a matte. This is useful for making the affected layer blend more realistically into your composite.

You can use the Matte Controls operator for files with embedded alpha channels, mattes created using the keyers, or any other layers or effects that act on a layer's alpha channel.

Matte Controls

The Matte Controls panel includes the following elements.

Invert

Inverts the matte.

Shrink

Removes pixels from the edge of the matte. Click Shrink and set the shrink width—the number of pixels to add or remove from the edge of the matte.

Erode

Can help blend a foreground clip into the background a little better by making the color of the background "spill" into the foreground edges, but without erasing the edge completely. Click Erode and set the erode width in pixels.

Matte Filter

Applies a horizontal or vertical blur filter to the matte. Click Matte Filter and set the number of pixels to blur in the vertical and horizontal directions. By default a proportional Gaussian blur is used. You can set the blur to Box in the Filter Type list.

Note: If you use shrink, erode, or blur when the subject in the front clip has detailed soft edges (such as hair), you may lose some of the fine detail.

To refine a matte using the Matte Controls operator:

1. With a matte layer selected, choose Operators | Keying | Matte Controls.

The Matte Controls panel appears.

2. Enable and adjust the Shrink, Erode, or Blur sliders to arrive at the right degree of edge softness.