JVET-P0375 Non-CE8: Palette mode CU size restriction [H. Yang, Y. He (InterDigital)]
Reviewed in Track A
Palette mode is included in VTM-6.0 for 4:4:4 screen content coding. However, due to the coding overhead cost of a palette table, it may not be efficient for small block sizes, especially for inter slices with much less frequent use of palette mode than that in I-slices. This contribution proposes to disable palette mode for inter slice CUs with sizes less than or equal to 32 samples. In simulation, CU size limit of 16, 32, 64 samples was tested. For the best performed 32 samples of the CU size limit, 4:4:4 CTC result shows that: compared with VTM-6.1 with palette mode, for dual-tree ON, −0.13%/−0.12% (RA/LDB) Y BD-rate gain is achieved, while for dual-tree OFF, −0.13%/+0.01% (RA/LDB) Y BD-rate change is achieved, all with similar encoding and decoding times.
No obvious benefit.