Patent ID: 7881380

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, (g) a flag indicating presence or non-presence of the weighting factor and offset concerning the luminance component and (h) a flag indicating presence or non-presence of the weighting factors and offsets concerning the first and second color difference components, and encoding, for a to-be-decoded block, an index indicating a combination selected from the plurality of combinations; 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 a reference image by the weighting factors, respectively, and adding the offsets, respectively, to results of the multiplying.