Rotoscoping is an animation technique in which animators trace over footage, frame by frame, for use in live-action and animated films. Originally, recorded live-action film images were projected onto a frosted glass panel and re-drawn by an animator. This projection equipment is called a rotoscope, although this device has been replaced by computers in recent years. In the visual effects industry, the term rotoscoping refers to the technique of manually creating a matte for an element on a live-action plate so it may be composited over another background.

The technique was invented by Max Fleischer, who used it in his series Out of the Inkwell starting around 1915, with his brother Dave Fleischer dressed in a clown outfit as the live-film reference for the character Koko the Clown. Max patented the method in 1917.

Fleischer used rotoscoping in a number of his later cartoons, most notably the Cab Calloway dance routines in three Betty Boop cartoons from the early 1930s, and the animation of Gulliver in Gulliver's Travels (1939). The Fleischer studio's most effective use of rotoscoping was in their series of action-oriented Superman cartoons, in which Superman and the other animated figures displayed very realistic movement.