MOTION VECTOR CODING AND DECODING METHODS

摘要

A motion vector coding apparatus includes a motion vector coding unit that codes a motion vector inputted from a motion vector detecting unit. A motion vector for each current block is coded based on a difference between the motion vector and a predicted vector obtained from motion vectors for previously coded neighboring blocks. The predicted vector is generated by one of: the motion vectors referring to the same picture are selected from among the motion vectors for the neighboring blocks; the motion vectors for neighboring blocks are ordered in the predetermined order and the motion vectors of the same order rank are selected; and the predicted vector for a second motion vector of the current block is the first motion vector, and when the second motion vector and the first motion vector refer to different pictures, the first motion vector is scaled based on temporal distance between the pictures.