CHROMA QUANTIZATION IN VIDEO CODING

摘要

A method of signaling additional chroma QP offset values that are specific to quantization groups is provided, in which each quantization group explicitly specifies its own set of chroma QP offset values. Alternatively, a table of possible sets of chroma QP offset values is specified in the header area of the picture, and each quantization group uses an index to select an entry from the table for determining its own set of chroma QP offset values. The quantization group specific chroma QP offset values are then used to determine the chroma QP values for blocks within the quantization group in addition to chroma QP offset values already specified for higher levels of the video coding hierarchy.

主权项

1. A method comprising:
identifying one or more initial sets of chroma quantization parameter (QP) offset values at one or more levels of a video coding hierarchy, each set of chroma QP offset values at a particular level for specifying chroma QPs of video units encompassed by said particular level; identifying an additional set of chroma QP offset values for a plurality of video units in the video coding hierarchy; and computing a set of chroma QP values for the plurality of video units, wherein the identified initial sets of chroma QP offset values and the identified additional set of chroma QP offset values are additive components of the set of chroma QP value for the plurality of video units.