No-reference IPTV Video Quality Modeling Based on Contextual Visual Distortion Estimation

No-reference IPTV H. 264 video quality modeling at bitstream level has just been standardized in ITU-T SG12/Q14 P.NBAMS work group as P.1202.2. Compression artifacts, channel artifacts, and their mutual influence are considered in the database design to reflect the realistic situations. For P.NBAMS, we contributed a no-reference slicing channel artifact measurement method based on contextual visual distortion estimation, shortly named CVD in this paper, which has been accepted into the final P.1202.2 Recommendation due to its best performance in standard competition. In CVD scheme, first we predicted the initial visibility of channel artifacts in an individual frame where packet loss occurs and detected the scene cut artifacts at bitstream level. Second, we applied a low-complexity zero-motion-based visible artifact propagation procedure, which emphasizes the most significant visual distortion rather than equally weights the propagated distortion and the initial distortion. Finally, we modeled the visibility of temporal artifacts by extracting two new features from the contextual distortions. The proposed CVD scheme outperforms or emulates the full-reference metric MSE on the five training databases of P.NBAMS, with an average correlation of 0.838 and an average RMSE of 0.42.