A Fast Four-Parameter Affine Motion Compensation Algorithm for Video Coding

This paper proposes a fast four-parameter Affine Motion Compensation (AMC) algorithm. As shown in Fig. 1, the translation Motion Vector (MV) is derived by reusing the AMC sub-block MV derivation method firstly, which is used to conduct translation pre-transform. Secondly, a coordinate system whose coordinate origin is located on its top-left control point is established for the transformed block. Finally, the geometric relationship between two control point motion vectors (CPMVs) of the transformed block can be described as follows,{equation*}δ = | {({m{v₀ₓ} - m{v₁ₓ}}) × H - ({m{v0y} + m{v1y}}) × W} | = 0{1}{equation*}