ABSTRACT
Professional compositors often find it necessary to remove blue-screen or green-screen from a live-action plate. Fortunately, a host of tools have been developed for such a task. The tools are generally called chroma keyers, as they target specific colors. Chroma keying is a critical part of professional compositing. As a process, chroma keying creates an alpha matte by targeting a specific color within a piece of film or video footage. This is necessary when shooting live action that utilizes a green-screen or blue-screen. Although green and blue are the most common colors used for chroma keying, it is possible to use chroma key compositing tools to target other colors, such as black or red. Hue-Keyer identifies a screen color through an interactive graph. With the graph, hue is represented by the left/right X axis. Nuke's advanced keyers were developed outside the program and are offered as plug-ins.
