Creating Alpha Channels with Keyers

You can key out a specific color or range of similar colors from a clip. When keying, the front image becomes transparent where a color (or range of colors) is keyed out.

After keying out a specific color, switch the view mode to Alpha to see the way the alpha channel is affected by the keying operation. In the previous example, the alpha channel for the front layer looks like the following.

You can perform keying using the following tools:

• Linear Keyer. This tool is useful for simple keys. For information, see Using the Linear Keyer.
• Difference Keyer. This tool is useful for creating a matte for a clip that was not shot in front of a blue screen. For information, see Using the Difference Keyer.
• Discreet Keyer. This tool is most useful for complex keying. For information, see Discreet Keyer.