Moving picture coding method and moving picture decoding method

摘要

According to a picture coding method, a coded picture is stored, as a reference picture, into a storage unit; commands indicating correspondence between reference pictures and reference indices for designating reference pictures and coefficients used for generation of predictive images are generated; a reference picture being used when motion compensation is performed on a current block in a current picture to be coded is designated by a reference index; a predictive image is generated by performing linear prediction on a block being obtained by motion estimation within the designated reference picture, by use of a coefficient corresponding to the reference index; a coded image signal including a coded signal obtained by coding a prediction error being a difference between the current block in the current picture to be coded and the predictive image, the commands, the reference index and the coefficient is outputted.

主权项

1. A picture decoding method comprising:
decoding a coded image signal to obtain: commands that indicate correspondence between plural reference pictures and plural reference indices designating the plural reference pictures; a reference index that identifies a reference picture for a current block to be decoded; and a prediction error for the current block; designating, based on the commands and the reference index, a reference picture which is referred to when the current block is decoded through motion compensation; generating a weighting coefficient based on display order information that indicates a display order of pictures; generating a predictive image by performing linear prediction, using the weighting coefficient, on pixel values of a reference block obtained from the reference picture designated in said designating; and generating a reconstructed image from the predictive image and the prediction error, wherein the reference index includes a first reference index that identifies a first reference picture and a second reference index that identifies a second reference picture, and in said generating of the predictive image, the predictive image is generated by performing linear prediction on the pixel values of the reference block using a pre-defined weighting coefficient when the first reference picture identified by the first reference index and the second reference picture identified by the second reference index have identical display order information.