| 摘要 |
The present disclosure relates to an image coding device and method, and an image decoding device and method for enabling the code amount of a chrominance signal in an image to be controlled. A chrominance signal quantization unit determines a luminance signal quantization parameter and a chrominance signal quantization parameter in units of CU by use of a luminance signal quantization parameter, a chrominance signal quantization parameter, and ChromaQPOffset from a rate control unit, and supplies the determined luminance signal quantization parameter and chrominance signal quantization parameter to a quantization unit. The chrominance signal quantization unit calculates a predictive quantization parameter predQP based on the quantization parameters of adjacent CUs. The chrominance signal quantization unit calculates deltaQP and ”QP C based on the determined luminance signal quantization parameter and chrominance signal quantization parameter and the calculated predictive quantization parameter predQP. The chrominance signal quantization unit supplies the calculated deltaQP, ”QP C , and ChromaQPOffset to a lossless coding unit. The present disclosure can be applied to an image processing device, for example. |
