Patent ID: 7864848
Filing Date: 2011-01-04
Classification: H04N

Abstract:
1. A video decoding method for decoding encoded data obtained by subjecting a video image to prediction encoding, the video image having a luminance component and first and second color difference components, the method comprising: receiving an input of encoded data obtained by encoding, for a to-be-decoded block, (1) a quantized orthogonal transform coefficient of a prediction error signal concerning luminance and two color differences, (2) information of motion vectors, and (3) a given number of indexes, each of the indexes indicating (A) a reference image and (B) a combination selected from a plurality of combinations, each combination comprising (a) a first weighting factor for the luminance component, (b) a second weighting factor for the first color difference component, (c) a third weighting factor for the second color difference component, (d) a first offset for the luminance component, (e) a second offset for the first color difference component, and (f) a third offset for the second color difference component; deriving the given number of the weighting factors and the given number of the offsets from the given number of indexes; generating a prediction image by multiplying the luminance and the first and second color difference components of the given number of reference images by the weighting factors corresponding to the respective reference images and adding the given number of the offsets, respectively, to results of the multiplying, based on the motion vectors; generating a prediction error signal by subjecting the quantized orthogonal transform coefficient to inverse quantization and inverse orthogonal transform; and generating a decoded image signal by calculating a sum of the prediction error signal and the prediction image, wherein two values of the index which correspond to the different reference images respectively indicate an identical combination of the weighting factors and the offsets.