Most probable direct mode for chroma intra mode coding

Abstract

The CST (Chroma Separate Tree) coding tool in VVC (Versatile Video Coding) allows different partition structures in the luma and chroma channels, and it gives significant coding efficiency for the chroma channel. Under CST, the DM mode can be less efficient when the current chroma block and its co-located luma block have different block shapes and sizes, thus less correlated. To solve this potential problem, we investigate a slightly modified DM mode, so called MPDM (Most Probable Direct Mode), to increase coding efficiency of the chroma intra coding. The proposed method is shown to achieve BDBR gain of -0.03% in the Y channel, -0.25% and -0.24% in the Cb and Cr channels, respectively. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.