Enhanced Adaptive Interpolation Filters for Video Coding

H.264/AVC uses motion compensated prediction with fractional-pixel precision to reduce temporal redundancy of the input video signal. It has been shown that the Adaptive Interpolation Filter (AIF) framework can significantly improve accuracy of the motion compensated prediction. In this paper, we present the Enhanced Adaptive Interpolation Filters (E-AIF) scheme, which enhances the AIF framework with a number of useful features, aimed at both improving performance and reducing complexity. These features include the full-pixel position filter and the filter offset, the radial-shaped 12-position filter support, and a RD-based filter selection. Simulations show that E-AIF can achieve up to 20% bit rate reduction compared to H.264/AVC. Compared to all other AIF schemes, E-AIF further reduces the bit rate by up to 6%, and demonstrates the highest performance consistently.