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

摘要

The image decoding method of an embodiment of the present invention includes: a context control step (S204) for determining the context to be used for a block to be processed, among a plurality of contexts; and an arithmetic decoding step (S210) for using the determined context to arithmetically decode a bit sequence corresponding to the block to be processed. In the context control step (S204), if a signal type for control parameters is a first type, the context is determined by using a condition that utilizes control parameters for both a left block and an above block, which are adjacent to the block to be processed (S206), and if the signal type for the control parameters is a second type, the context is determined by using a condition that does not utilize the control parameter for the above block (S207). The second type is "ref_idx_l0" or "ref_idx_l1".