| 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 the 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; constructing an intra prediction mode group consisting of three intra prediction modes, wherein the three intra prediction modes are determined using an intra prediction mode of a left block of a current block and an intra prediction mode of an above block of the current block; deriving an intra prediction mode of the current block using the 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 the 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 the 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 planar mode and one of directional modes, and 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 planar mode when the intra prediction modes of the left and the above blocks are not equal to each other and are directional intra prediction modes. |
