Abstract
Traditional intra prediction schemes usually only use the nearest adjacent reference line to generate the prediction. Although the nearest reference line generally has the strongest statistical correlation with current block, the farther non-adjacent reference lines can still provide potential better prediction in some cases. Thus, in this paper, not only the nearest reference line but also the farther reference lines are utilized to help intra prediction. When using the farther reference lines, an additional residue compensation procedure is introduced to further refine the prediction. In particular, this paper designs three solutions to meet different complexity requirements. They are multiple line-based intra prediction (MLIP), fast search for multiple line-based intra prediction (FS-MLIP), and dual line-based intra prediction (DLIP). Experimental results verify the effectiveness of the proposed methods. When compared with HM-16.9, the proposed MLIP achieves 2.4% bit saving on average with the encoding time increasing about 362%. The FS-MLIP achieves 2.0% bit saving on average with the encoding time increasing about 114%. The DLIP achieves 0.9% bit saving on average with the encoding time increasing about only 15%.