Patent ID: 8355588
Filing Date: 2013-01-15
Classification: H04N

Abstract:
1. A picture coding method comprising: generating commands comprising first commands and second commands, the first commands indicating correspondence between first reference indices and first reference pictures, each of the first reference indices being an index for designating the first reference picture, and the second commands indicating correspondence between second reference indices and second reference pictures, each of the second reference indices being an index for designating the second reference picture; determining a first maximum reference index value for indicating a maximum value of the first reference index and a second maximum reference index value for indicating a maximum value of the second reference index; determining plural sets of weighting coefficients; assigning a first reference index corresponding to a first reference picture and a second reference index corresponding to a second reference picture for a current block to be coded, the first and second reference pictures being referred to when the current block is coded through motion compensation; specifying two sets of weighting coefficients that correspond to the first and second reference indices in said assigning from among the plural sets of weighting coefficients; generating a first predictive image by performing linear prediction on pixel values of a first reference block, using one of the specified two sets of weighting coefficients corresponding to the assigned first reference index, and generating a second predictive image by performing linear prediction on pixel values of a second reference block, using the other of the specified two sets of weighting coefficients corresponding to the assigned second reference index, the first reference block being obtained from the first reference picture corresponding to the assigned first reference index and the second reference block being obtained from the second reference picture corresponding to the assigned second reference index; generating a predictive image using the first predictive image and the second predictive image; 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 commands; the first maximum reference index value and the second maximum reference index value; plural sets of weighting coefficients; the first reference index assigned to the first reference picture and the second reference index assigned to the second reference picture in said assigning; and the prediction error, wherein, in the case that the current block is a block included in a B picture and the current block is coded by referring to the first reference picture and the second reference picture, one of the specified two sets of weighting coefficients comprises a first part w