Glossary
Optical flow
The per-pixel motion field between consecutive video frames — the direction and distance each point in the image appears to move. A core signal for video understanding and generation.
Flow estimators are trained largely on synthetic scenes, where true motion is known exactly, and then applied to real footage. Flow feeds action recognition, tracking, stabilization, compression, and world models’ grasp of motion and physics. High-frame-rate, lightly compressed footage yields clean flow; heavy compression corrupts the motion signal with artifacts.
Why it matters
Motion quality is one reason original masters beat platform-compressed copies for video training.