Patent ID: 7881382

Claim:
A prediction image generation apparatus for generating a prediction image from 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 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 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 weighting factor and offset concerning the luminance component, and encoding, for a to-be-decoded block, (A) information of a motion vector and (B) an index indicating (a) a combination selected from the plurality of combinations and (b) a reference image; a deriving module configured to derive, for the to-be-decoded block, the weighting factors and the offsets from the index and the plurality of combinations; and a generator configured to generate a prediction image by multiplying the luminance component and the 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.