Rotoscoping is an animation technique that animators use to trace over motion picture footage, frame by frame, to produce realistic action. Originally, animators projected photographed live-action movie images onto a glass panel and traced over the image. This projection equipment is referred to as a rotoscope, developed by Polish-American animator Max Fleischer, and the result is a rotograph. This device was eventually replaced by computers, but the process is still called rotoscoping.

In the visual effects industry, rotoscoping is the technique of manually creating a matte for an element on a live-action plate so it may be composited over another background. Chroma key is more often used for this, as it is faster and requires less work, but rotoscopy provides a higher level of accuracy and is often used in conjunction with chroma-keying. It may also be used if the subject is not in front of a green (or blue) screen, or for practical or economic reasons.