JVET-L0065 CE3-related: One-line CCLM for reduction of reference sample lines [J. Lee, J. Byeon, S. Park, D. Sim (KWU)]
This contribution presents a modified Cross Component Linear Model (CCLM) methods with one-line luminance sample line for down-sampling process. In the CCLM mode in VTM2.0.1, two upper neighbouring reconstructed luminance lines are required in the down-sampling process. The proposed method uses one reconstructed luminance sample line, that is upper adjacent to the corresponding Luma block to the current chroma CU in order to reduce a luminance line buffer. Experimental results show that the proposed method yields BD-rate loss of 0.02%, 0.23%, and 0.22% for three colour components on average over VTM2.0.1 with CCLM, respectively.
The contribution does not need more consideration due to the decision to restrict CCLM only at the CTU boundary (where the advantage would be minor).
JVET-L0329 proposes a similar approach.