Patent ID: 9554130
Date: 2017-01-24
CPC Classifications: H04N

Claim:
1. An intra-prediction method comprising: decoding flag information indicating whether one of a plurality of candidate intra-prediction modes with respect to a current block and an intra-prediction mode of the current block are identical; and when one of a plurality of candidate intra-prediction modes with respect to a current block and an intra-prediction mode of the current block are not identical, decoding a syntax element comprising information regarding the intra-prediction mode of the current block to derive the intra-prediction mode of the current block, wherein, the decoding of a syntax element comprising information regarding the intra-prediction mode of the current block to derive the intra-prediction mode of the current block is performed based on a table comprising intra-prediction mode information, the table is a table mapping intra-prediction modes and index information of the intra-prediction modes, and, in the table, when an intra-prediction mode is a planar mode, the intra-prediction mode is mapped to an index 0, when an intra-prediction mode is a DC mode, the intra-prediction mode is mapped to an index 1, and when intra-prediction modes are directional intra-prediction modes, the intra-prediction modes are mapped to indices 2 to 34 according to directivity of the intra-prediction modes, wherein the plurality of candidate intra-prediction modes with respect to the current block are three different intra-prediction modes derived based on at least one intra-prediction mode derived based on neighbor blocks of the current block and an additional intra-prediction mode.