Patent ID: 8194746

Claim:
A method of coding a moving picture including a procedure for dividing a picture into plural coding blocks, predicting a motion vector (MV) of the coding block from a motion vector of the adjacent block to be a predictive motion vector (PMV) and coding a differential motion vector (MVD) calculated based upon the motion vector to be coded and its predictive motion vector in units of block, comprising: a procedure for preparing some types of accuracy of the motion vector, calculating the differential motion vector (MVD) using an expression, MVD =(MV −((PMV >>mv shift) <<mv shift)) >>mv shift, or MVD =(MV >>mv shift)−(PMV >>mv shift), selecting the accuracy of a motion vector every coding block, with determining a value of the mv shift of the expression, and coding the information of the selected accuracy and a differential motion vector (MVD) calculated based upon the predictive motion vector (PMV) revised to the selected accuracy and the motion vector (MV) at the selected accuracy.