Motion vector coding method and motion vector decoding method

摘要

A motion vector coding unit executes processing including a neighboring block specification step of specifying a neighboring block which is located in the neighborhood of a current block; a judgment step of judging whether or not the neighboring block has been coded using a motion vector of another block; a prediction step of deriving a predictive motion vector of the current block using a motion vector calculated from the motion vector of the other block as a motion vector of the neighboring block; and a coding step of coding the motion vector of the current block using the predictive motion vector.

主权项

1. A picture decoding apparatus for decoding a moving picture, comprising:
a neighboring block specification unit that specifies a plurality of neighboring blocks which are located in a neighborhood of a current block and has already been decoded; a judgment unit that judges if each of the plurality of neighboring blocks does not have a coded motion vector in a bit stream and has been decoded using a motion vector of another block; a different motion vector determining unit that determines a different motion vector of each of the plurality of neighboring blocks based on the result of the judgment unit; a prediction unit that derives a predictive motion vector of the current block using different motion vectors of the plurality of neighboring blocks; a motion vector decoding unit that decodes a coded motion vector of the current block to obtain a decoded difference motion vector of the current block; a motion vector recovering unit that recovers the motion vector of the current block by adding the decoded difference motion vector of the current block and the predictive motion vector of the current block; and a picture decoding unit that decodes the coded picture corresponding to the current block by using the motion vector which has been recovered by the motion vector recovering unit, wherein, when the judgment unit judges that the neighboring block does not have a coded motion vector in a bit stream and has been decoded using the motion vector of the other block, a motion vector, which is calculated from the motion vector of the other block and which is used in a motion compensation of the neighboring block, is determined as a different motion vector of the neighboring block by the different motion vector determining unit, and when the judgment unit judges that the neighboring block has a coded motion vector in a bit stream and has been decoded without using the motion vector of the other block, a motion vector, which is detected in a coding process of the neighboring block and which is used in a motion compensation of the neighboring block, is determined as a different motion vector of the neighboring block by the different motion vector determining unit.