Disclosed herein is a method for adaptive bidirectional optical flow estimation for inter-screen prediction compensation during video encoding. The method aims to reduce complexity and/or cost of bidirectional optical flow (BIO) at a pixel level or a subblock level.
By solving Equation 4, which is the system of equations, vx and vy may be estimated. For example, using Cramer's rule, vx and vy may be derived as Equation 6.