Video Coding With Low-Complexity Directional Adaptive Interpolation Filters

Abstract — A novel adaptive interpolation filter structure for video coding with motion-compensated prediction is presented in this letter. The proposed scheme uses an independent directional adaptive interpolation filter for each sub-pixel location. The Wiener interpolation filter coefficients are computed analytically for each inter-coded frame at the encoder side and transmitted to the decoder. Experimental results show that the proposed method achieves up to 1.1 dB coding gain and a 15 % average bit-rate reduction for high-resolution video materials compared to the standard nonadaptive interpolation scheme of H.264/AVC, while requiring 36 % fewer arithmetic operations for interpolation. The proposed interpolation can be implemented in exactly 16-bit arithmetic, thus it can have important use-cases in mobile multimedia environments where the computational resources are severely constrained. Index Terms — Adaptive filters, interpolation, motioncompensation, video coding. I