Adobe After Effects CS4 Classroom in a Book

Chapter 9. Keying

Lesson overview

In this lesson, you’ll learn how to do the following:

• Create a garbage mask.

• Use the Color Difference Key effect to key an image.

• Check an image’s alpha channel for errors in a key.

• Choke a matte to refine a key.

• Use the Spill Suppressor effect to remove unwanted light spill.

• Key out a background using the Keylight effect.

• Adjust the contrast of an image using the Levels effect.

• Prepare a project for mobile devices using Adobe Device Central.

In this lesson, you will create an introductory menu for a fictional sports network, called Mobile Sports Network, which provides sports scores and stats on mobile phones. You’ll work ...