De-ringing filter for Scalable Video Coding

This paper reports the recent inter-layer filtering development for the scalable extension of the high-efficiency video coding (HEVC). The essential difference between scalable and single-layer video coding technology is the existence of the inter-layer redundancy, which can be exploited by the interlayer prediction to improve the coding efficiency. One form of inter-layer prediction is to up-sample the reconstructed base-layer picture as a predictor for the enhancement-layer. However, due to the intrinsic filter characteristics during the resampling process and the quantization error in the base-layer, this prediction picture often has low quality, with significant ringing artifacts. This paper proposes an adaptive de-ringing filter to reduce such ringing artifacts. With the reduction of the ringing artifacts, inter-layer prediction can be more effective and coding efficiency can be improved. Simulation result shows that on average from 0.5% to 1.7% and up to 4.6% BD-Rate (Bjontegaard Delta-Rate) saving can be achieved using this single tool for emerging HEVC scalability extension.