Method of generating reconstructed block

摘要

Provided is a method that derives an intra prediction mode of a prediction unit, determines a size of a current block using transform size information, generates a prediction block of the current block according to the intra prediction mode, generating a residual block of the current block according to the intra prediction mode and generating a reconstructed block of the current block using the prediction block and the residual block. The sizes of the prediction block and the residual block are set equal to a size of a transform unit. Therefore, the distance of intra prediction becomes short, and the amount of coding bits of residual block is reduced by generating a prediction block very similar to original block. Also, the signaling bits required to signal intra prediction mode decrease by generating MPM group adaptively according to the neighboring intra prediction modes.

主权项

1. An image decoding method comprising:
deriving an intra prediction mode using three intra prediction modes which are determined by left and above intra prediction modes of a current prediction unit; generating a prediction block according to the intra prediction mode; generating a residual block using the intra prediction mode; and generating a reconstructed block using the prediction block and the residual block, wherein a size of the prediction block is determined by transform size information, wherein the residual block is generated by inversely scanning quantized coefficient information using an inverse scan pattern to generate a quantized block, by inversely quantizing the quantized block using a quantization parameter to generate a transformed block, and by inversely transforming the quantized block, wherein the intra prediction mode is derived by constructing a Most Probable Mode (MPM) group including three intra prediction modes determined based on the left intra prediction mode and the above intra prediction mode, by setting an intra prediction mode of the MPM group specified by a prediction mode index as the intra prediction mode of the current prediction unit if a mode group indicator indicates the MPM group, and by determining the intra prediction mode of the current prediction unit by comparing the prediction mode index with the three intra prediction modes of the MPM group if the mode group indicator does not indicate the MPM group, and wherein if only one of the left intra prediction mode and the above intra prediction mode is available, the MPM group includes the available intra prediction mode and two additional intra prediction modes determined according to the available intra prediction mode.