| 主权项 |
1. An image decoding device, the device comprising:
a processor, and a non-transitory computer-readable medium having stored thereon instructions that, when executed, cause the processor to perform a method, the method comprising: scanning quantized coefficients to generate a quantization block; inversely quantizing the quantization block using a quantization parameter, wherein the quantization parameter is derived using a received residual quantization parameter, and a quantization parameter predictor is generated using a left quantization parameter of a current coding unit and an above quantization parameter of the current coding unit; generating a residual block by inversely-transforming the inversely-quantized block; reconstructing a first intra prediction mode group which consists of three intra prediction modes among 34 intra prediction modes, wherein the three intra prediction modes of the first intra prediction mode group are determined using intra prediction modes of a left and an above blocks of a current block; deriving an intra prediction mode of the current block using the first intra prediction mode group, wherein the intra prediction mode of the current block is set as an intra prediction mode specified by a prediction mode index in an intra prediction mode group when an intra prediction mode group indicator indicates the intra prediction mode group is used, and the intra prediction mode of the current block is set as an intra prediction mode indicated by the prediction mode index among intra prediction modes excepting the three intra prediction modes in intra prediction mode group when the intra prediction mode group indicator indicates the intra prediction mode of the current block is one of the intra prediction modes not included in the intra prediction mode group, generating a prediction block of the current block using the derived intra prediction mode, and generating a reconstructed block using the prediction block and the residual block, wherein the three intra prediction modes in the intra prediction mode group are the intra prediction modes of the left and the above blocks and a DC mode when the intra prediction modes of the left and the above blocks are a DC mode and one of directional modes, and wherein in the operation of inversely quantizing, the quantization parameter is enabled to be changed per a minimum quantization coding unit, and a size of the minimum quantization coding unit is signaled per picture. |
