3Working with Keyers
WWW To download the web content for this chapter go to the website www.routledge.com/cw/wright, select this book then click on Chapter 3.
3.1 Keyers
A very important point to keep in mind is that pulling a key from an image, even a perfectly shot greenscreen, is in fact a clever cheat – it is not mathematically valid. It is a fundamentally flawed process that merely appears to work fairly well under most circumstances, so we should not be surprised when things go badly – which they often do. A key is supposed to be an “opacity map” of the target object within the greenscreen image. It is supposed to correctly reflect semi-transparencies at the object’s edges and any other partially transparent regions. Because the keying ...
Get Digital Compositing for Film and Video, 4th Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
