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

An image decoding device includes a processor and storage configured to receive a bitstream from a server based on an instruction sent from an apparatus, decode an image on a block-by-block basis, from the bitstream and send the image to a display apparatus. The decoding includes obtaining first, second, third and fourth data, where context adaptive binary arithmetic decoding is performed on the first data, bypass decoding is performed on the second data, context adaptive binary arithmetic decoding is performed on the third data, and bypass decoding is separately performed on the fourth data. Four luma intra prediction modes are derived from a respective one of four luma context-dependent segments and a corresponding one of four luma context-independent segments for four subblocks in an image block, and one chroma intra prediction mode is derived from one chroma context-dependent segment and one chroma context-independent segment for the image block.