In-loop noise shaping based on pseudo noise injection and Wiener filtering

This paper proposes an in-loop noise shaping method based on the combination of pseudo noise injection and Wiener filtering for High Efficiency Video Coding (HEVC). In deblocking process, the proposed method injects pseudo noise into the vicinities of deblocked edges where signal-dependent coding noises are supposed to appear. The pseudo noise injection introduces a masking effect of signal-dependent noise with signal-independent noise. Since subsequently applied Wiener filtering accomplishes optimal noise reduction in a minimum-mean-squared-errors sense, it minimizes the deleterious impact of the pseudo noise injection on coding performance. Simulation results using HEVC Test Model software show that the proposed method successfully suppresses banding artifacts with a negligible impact on PSNR values, bit rates, and encoder/decoder runtime measures.