Movies - Making Chroma Keys
BACKGROUND: If one has watched the evening news where the weatherman stands in front of a large weather map, you would be experiencing what is called in television and movies “Chroma Key”. In television it is often called “Green Screen” because the screen the weatherman stand in front of is a green curtain. The control room of the TV station “blends” this image of the weatherman with an animation of a map by selectively removing the green around the weatherman. This allows the map to become the background which replaces the removed green curtain. In the movies it is more common to use a light sky blue instead of the green. The difference has to do with the difference between primary colors in light and those in film. In either case, any color can be selectively removed.