Patent ID: 7852925

Claim:
A prediction image generation apparatus of 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 apparatus comprising: a receiver configured to receive an input of encoded data obtained by encoding, for one or more to-be-decoded blocks, 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, (F) a third offset for the second color difference component, and (G) a flag indicating presence or non-presence of the first weighting factor and the first offset for the luminance component, and encoding, for a to-be-decoded block, (1) information of a motion vector and (2) an index indicating a combination of the plurality of combinations; a deriving module configured to derive, for a to-be-decoded block, the weighting factors and the offsets from the index and the plurality of combinations; and a generator configured to generate the prediction image by multiplying the luminance and first and second color difference components of a reference image by the weighting factors, respectively, and adding the offsets, respectively, to results of the multiplying, based on the motion vector.