Patent ID: 7924924

Claim:
A motion vector decoding device for decoding an output of a motion vector encoding device which predicts a motion vector of a target block within a frame based on motion vectors of a plurality of blocks adjacent to the target block within the frame, determines accuracy of a prediction based on degrees of non-uniformity of a plurality of motion vectors which have already been encoded in an area adjacent to the target block, and encodes the motion vector of the target block by using a result of the prediction with an encoding method determined based on a result of a determination of the accuracy of the prediction, in order to encode motion vectors of respective blocks obtained by partitioning each frame of moving image data, comprising: predicting means for predicting the motion vector of the target block within the frame based on motion vectors of at least two of the plurality of blocks adjacent to the target block used to make the determination within the motion vector encoding device; determining means for determining accuracy of a prediction made by said predicting means based on the degrees of difference between motion vectors of a plurality of blocks adjacent to the target block by determining whether differences between any of the vectors is greater than a threshold; and decoding means for decoding the motion vector of the target block by using a result of the prediction made by said predicting means with a decoding method determined based on a results of a determination made by said determining means.