In some embodiments, the flag “cu_qp_update_signal” can take on additional possible values for handling different options for specifying chroma QP offset values. For example, in some embodiments, if the flag is ‘0’, the chroma QP offset values from the left neighboring quantization group are used, if the flag is ‘1’, the chroma QP offset values from the top neighboring quantization group are used; and if the flag is ‘2’, the current quantization group will explicitly specify a new set of chroma QP offset values Otherwise, the current quantization group will use the default QP offset values from the PPS and/or the slice header. In some embodiments, the chroma QP offset values inherited by the current quantization group are based on the average of the chroma QP offset values of at least two of the neighboring quantization groups (e.g., the left and the top).

To further reduce overhead, some embodiments specify that these additional chroma QP offsets can only be within a small range of values, i.e. from a value ?x to x. Doing so changes the entropy coding process since it alters the expected statistics of the information to be signaled (i.e. for Context Adaptive Binary Arithmetic (CABAC) coding, or if using a “max-limited” universal variable length coding scheme). In some embodiments, the value of x (i.e., the range) is prefixed for the entire sequence; or is signaled at a higher syntax level such as the PPS, SPS, or slice header. Some of these embodiments accomplish this by specifying x directly, or, if x corresponds to a power of 2, the value log 2(x). Some embodiments specify x by separating magnitude, i.e. abs(x), and the sign of x. In CABAC, the value of abs(x) corresponds to the cMax parameter needed in the binarization process,

b. Specifying Additional Chroma QP Offsets in a Table