Chrome key composting, or chrome keying, is a special effects / post-production technique for composting (layering) two images or video streams together based on color hues.
The technique has been used heavily in many fields to remove a background from the subject of a photo or video – particularly the news-casting, motion picture and video game industries.
A color range in the top layer is made transparent, revealing another image behind. The chrome keying technique is commonly used in video production and post-production.
The advanced state of the technology and much commercially available computer software, such as Autodesk Smoke, Final Cut Pro, Pinnacle Studio, Adobe After Effects, and dozens of other computer programs, makes it possible and relatively easy for the average home computer user to create videos using the "chrome key" function with easily affordable green screen or blue screen kits