Chroma quantization parameter extension

摘要

The quantization parameters (QP) for Chroma are extended up to and more preferably to the same range as Luma QP (e.g., 0 to 51). Previous, values of Chroma QP only extended up to 39. Techniques are provided for determining extended Chroma QP values (e.g., for Cr and Cb) based on the Luma QP and picture level chroma offsets. In one preferred embodiment, slice level offsets are added making the method particularly well-suited for slice level parallel processing. The extension of Chroma QP enhances functionality, flexibility and friendliness of the High Efficiency Video Coding (HEVC) standard for various applications.

主权项

1. An encoding apparatus, comprising:
circuitry configured to: determine chroma quantization parameters for Chroma blue (Cb) and Chroma red (Cr) based on a luma quantization parameter and picture level chroma quantization parameter offsets for Cb and Cr which are added to the luma quantization parameter, said chroma quantization parameters for Cb and Cr having a range that substantially equals a luma quantization parameter range from 0 to 51; and perform quantization on chroma transform coefficients for Cb and Cr using said chroma quantization parameters for Cb and Cr.