Intra Prediction Using Multiple Reference Lines for Video Coding
Traditional intra prediction schemes usually only use the nearest adjacent reference lineto generate the prediction. Although the nearest reference line generally has the strongeststatistical correlation with current block, the farther non-adjacent reference lines can stillprovide potentialb etter prediction in some cases. Thus, in this paper, not only the nearestreference line but also the farther reference lines are utilized to help intra prediction. Whenusing the farther reference lines, an additional residue compensation procedure is introducedto further refine the prediction. In particular, this paper designs three solutions to meetdifferent complexity requirements. They are multiple line-based intra prediction (MLIP),fast search for multiple line-based intra prediction (FS-MLIP), and dual line-based intraprediction (DLIP). Experimentalresul ts verify the effectiveness of the proposed methods. When compared with HM-16.9, the proposed MLIP achieves 2.4% bit saving on averagewith the encoding time increasing about 362%. The FS-MLIP achieves 2.0% bit saving onaverage with the encoding time increasing about 114%. The DLIP achieves 0.9% bit savingon average with the encoding time increasing about only 15%.