27 Keying

Effectively removing a color background requires attention throughout the chain

Compositing images shot against one background over a new background is one of the trickier visual effects tasks you will encounter. It requires separating the foreground elements from the original background they were shot against. Even if the foreground comes with its own alpha channel (the result of a 3D render), getting it to blend nicely with its new background can still be a challenge.

Time for the bad news: Not all images can be cleanly separated from their background. Neither can you assume that all images can be seamlessly blended with a new background. But with some preplanning and patience, you should be able to produce professional images. This ...

Get Creating Motion Graphics with After Effects, 5th Edition now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.