Patent ID: 7852933

Claim:
A prediction image generation method for generating a prediction image by decoding encoded data obtained by subjecting a video image to prediction encoding, the video image comprising 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) an index indicating (A) a reference image and (B) a 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, and (2) information of a motion vector; deriving, for the to-be-decoded block, the reference image, the weighting factors and the offsets from the index; and generating a prediction image by multiplying the luminance and first and second color difference components of the reference image by the weighting factors, respectively, and adding the offsets, respectively, to results of the multiplying, based on the motion vector.