How They Make Great Movie Scenes
These days they don`t even have to leave the studio to make a good movie scene. Green screen is all they need.
Chroma keying is a technique for mixing two images or frames together in which a color (or a small color range) from one image is removed (or made transparent), revealing another image behind it. This technique is also referred to as color keying, colour-separation overlay, greenscreen, and bluescreen.