| 摘要 |
PROBLEM TO BE SOLVED: To provide an image decoding apparatus suitable for improving image expression efficiency.SOLUTION: A method for encoding an intra prediction mode selects an intra prediction mode for a current block, determines the number of valid MPM candidates by checking the validity of MPM candidates of the current block, and if the number of valid MPM candidates is less than a previously set number, adds additional intra prediction modes as MPM candidates. MPM candidates can be adaptively added on the basis of the directionality of the valid MPM candidates. Additionally, even during the encoding of residual intra prediction modes, the residual intra prediction modes are realigned on the basis of the directionality of the valid MPM candidates. Accordingly, the information for encoding the intra prediction mode of the current block is minimized by adding MPM candidates and/or realigning the residual intra prediction modes on the basis of the directionality of the valid MPM candidates. |
