IMAGE DECODING METHOD, IMAGE CODING METHOD, IMAGE DECODING APPARATUS, IMAGE CODING APPARATUS, AND IMAGE CODING AND DECODING APPARATUS

摘要

Provided is an image decoding method that decodes, for each block, image data included in an encoded stream, and that comprises the following steps: a derivation step for deriving candidates for intra-prediction modes of which there are always at least two, the candidates being intra-prediction mode candidates used for intra-screen prediction of a decoding subject block; an acquisition step for acquiring an index from the encoded stream in order to specify one candidate from the derived intra-prediction mode candidates; a selection step for selecting on the basis of the acquired index one candidate, from the derived intra-prediction mode candidates, as the intra-prediction mode used for intra-screen prediction of a decoding subject block.