IMAGE DECODING DEVICE, IMAGE DECODING METHOD, AND IMAGE DECODING PROGRAM

摘要

PROBLEM TO BE SOLVED: To reduce an entire code amount by further compressing encoding information in an image encoding system using hierarchical encoding.SOLUTION: An image decoding device decodes an encoding bit string in which an image is encoded with inter-prediction at a block unit obtained by dividing a picture of each hierarchy using scalable encoding for hierarchical encoding. A merge candidate creation part 231 derives a candidate of inter-prediction information between hierarchies, a candidate of spatial inter-prediction information, and a candidate of time-inter prediction information. The merge candidate creation part 231 excludes the candidate of the time inter-prediction information from the candidate of the inter-prediction information when the candidate of the inter-prediction information between the hierarchies can be derived.