| CPC H04N 19/186 (2014.11) [H04N 19/107 (2014.11); H04N 19/12 (2014.11); H04N 19/124 (2014.11); H04N 19/132 (2014.11); H04N 19/159 (2014.11); H04N 19/172 (2014.11); H04N 19/18 (2014.11); H04N 19/61 (2014.11); H04N 19/70 (2014.11)] | 4 Claims |
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1. An image decoding method, performed by a decoding apparatus, the method comprising:
obtaining image information including prediction information residual information for chroma components, and a flag representing whether one chroma quantization parameter table is applied or not;
obtaining chroma quantization parameter data based on the flag;
deriving at least one chroma quantization parameter table based on the chroma quantization parameter data;
deriving at least one chroma quantization parameter for the chroma components based on the at least one chroma quantization parameter table;
deriving prediction samples for the chroma components based on the prediction information;
deriving transform coefficients for the chroma components based on the residual information;
deriving residual samples for chroma components by dequantizing the transform coefficients based on the at least one chroma quantization parameter; and
generating a reconstructed picture based on the prediction samples and the residual samples,
wherein the flag equal to 0 represents that a first chroma quantization parameter table for a Cb component a second chroma quantization parameter table for a Cr component and a third chroma quantization parameter table for a joint CbCr component are signaled.
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