Approximation method for interpolating affine parameters in doubling frame rate

The quality of the frame rate up-conversion depends on the accuracy of the motion parameters. 2D affine model describes the motion better than the popular 2D translation model; however, its parameters are difficult to interpolate. In this paper, the approximation method for interpolating the mid-point of 2D affine parameters is proposed. The affine transform is approximated as the 2D rigid transformation where the target x and y axes are not orthogonal. Trigonometry relationship is applied to interpolate rotational parameters. Conventional linear interpolation is applied to interpolate translational parameters. For video sequences containing complex motion, the reconstruction from the approximated affine parameters gave higher PSNR and visually better result than the one from the interpolated 2D translation parameters.