主权项 |
1. An intra-prediction method comprising:
decoding flag information indicating whether one of a 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 the candidate intra-prediction modes with respect to the current block and an intra-prediction mode of the current block are not identical, decoding a syntax element of remaining intra-prediction mode information 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 the syntax element is performed based on a table comprising intra-prediction mode information, the table mapping intra-prediction modes and index information of the intra-prediction modes, wherein 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 a codeword length of an index of the candidate intra-prediction modes with respect to the current block is shorter than a codeword length of an index of the remaining intra-prediction mode information, wherein the candidate intra-prediction modes with respect to the current block are modes for predicting luminance information, and wherein chrominance information of the current block is predicted based on intra-prediction mode information according to the predicting luminance information. |