Patent ID: 7813568

Claim:
A picture coding method comprising: generating commands indicating correspondence between reference pictures and reference indices designating the reference pictures; determining a maximum value of the reference indices; determining a weighting coefficient set for a reference index so as to determine a plurality of weighting coefficient sets for the reference indices; assigning a reference index to a reference picture, the reference picture being referred to when motion compensation is performed on a current block to be coded; generating a predictive image by performing linear prediction on pixel values of a reference block, using the weighting coefficient set corresponding to the assigned reference index, the reference block being obtained by motion estimation between the reference picture and the current block to be coded; generating a prediction error that is a difference between the current block to be coded and the predictive image; and outputting a coded image signal obtained by coding: the reference index assigned to the reference picture in said assigning; information indicating the maximum value of the reference indices; the commands; the weighting coefficient sets; and the prediction error.