| 摘要 |
Video coding such as HEVC includes a chrominance prediction mode in which a current block of chrominance samples representing an image region (1210) is encoded by deriving and encoding a relationship of the chrominance samples with respect to a co-sited block of luminance samples representing the same image region. The relationship is derived by comparing correspondingly-sited luminance and chrominance samples from adjacent already-encoded blocks. In a first sampling resolution (e.g. 4:4:4), where the chrominance and luminance samples have the same sampling rate, the correspondingly-sited samples are in sample positions adjacent to the current block. In a second sampling resolution (e.g. 4:2:2, 4:2:0), where the chrominance samples have a lower sampling rate than that of the luminance samples, the correspondingly-sited samples are a nearest column or row of correspondingly-sited luminance and chrominance samples from the adjacent already encoded blocks. The chrominance samples are then predicted from luminance samples according to the relationship, and the difference between the predicted chrominance samples and the actual chrominance samples is encoded. Other features of HEVC coding are also disclosed. |
