What is Green Screen
Green Screen is commonly used for weather forecast broadcasts, wherein a news presenter is usually seen standing in front of a large CGI map during live television newscasts, though in actuality it is a large blue or green background. When using a blue screen, different weather maps are added on the parts of the image where the color is blue. If the news presenter wears blue clothes, his or her clothes will also be replaced with the background video. Chroma keying is also common in the entertainment industry for special effects in movies, video-games and corporate video productions.
Chroma keying can be done with backgrounds of any color that are uniform and distinct, but a green background is more commonly used because it differs most distinctly in hue from most human skin colors. No part of the subject being filmed or photographed may duplicate the color used as the backing.