Rotoscoping is the technique of manually tracing over live-action footage frame by frame to create precise outlines or mattes of moving subjects, enabling clean separation of foreground elements from their backgrounds for compositing, visual effects, or stylistic treatment. The term comes from the Rotoscope, a device patented by Max Fleischer in 1915 that projected film frames onto a drawing surface so animators could trace realistic human movement.

In contemporary production, rotoscoping is used primarily to create clean mattes for compositing - cutting subjects out of their original backgrounds with precision to place them in different environments, remove unwanted elements, or apply effects selectively to specific areas of footage. While automated tools and AI-powered rotoscoping have dramatically accelerated what was previously an entirely manual frame-by-frame process, complex footage with challenging edges, fine detail like hair, or rapid motion still often requires artist intervention to achieve clean results. Rotoscoping is also used artistically in animation to trace live-action movement for stylized animated sequences, a technique used in films like A-ha's "Take On Me" music video and Richard Linklater's Waking Life.

AI-powered rotoscoping tools have made background removal and subject isolation significantly more accessible for individual creators and small productions. In AI video workflows, clean rotoscoped mattes of subjects enable compositing AI-generated backgrounds behind real footage, layering AI-generated elements in front of live-action material, and creating hybrid productions that combine generated and photographed content in a single coherent frame.