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

摘要

PROBLEM TO BE SOLVED: To enable further compression of encoded information and reduction of the overall encoding amount in an image encoding system using hierarchical encoding.SOLUTION: In an image decoding device for decoding an encoded bit string in which an image is encoded by using a motion vector for each of block units into which a picture of each layer is encoded by using scalable coding, a prediction motion vector candidate generator 241 derives a prediction motion vector candidate from the motion vector of a decoded prediction block which is within the same picture as a decoding target prediction block in an expanded layer and close to the decoding target prediction block, and the prediction motion vector candidate is derived from the motion vector of the prediction block in a decoded picture of a lower layer than the decoding target prediction block. Based on a decoded flag, a prediction motion vector selecting unit 245 selects a prediction motion vector candidate as the prediction motion vector of the decoding target prediction block from derived candidates of the prediction motion vector.SELECTED DRAWING: Figure 34