Patent ID: 7864844

Claim:
A video decoding apparatus of decoding encoded data obtained by subjecting a video image to motion compensation prediction encoding, the video image having a luminance component and first and second color difference components, the video decoding apparatus comprising: a receiver configured to receive, as an input, 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, and (F) a third offset for the second color difference component and encoding (1) a quantized orthogonal-transformed coefficient of a prediction error signal concerning the luminance component and the first and second color difference components, (2) information of a motion vector and (3) an index indicating a combination of the plurality of combinations; a deriving module configured to derive, for the to-be-decoded block, a combination comprising the weighting factors and the offsets from the index and the plurality of combinations; a first generator configured to generate the prediction error signal for the to-be-decoded block by subjecting the quantized orthogonal-transformed coefficient to inverse quantization and inverse orthogonal transform; a second generator configured to generate a motion compensation prediction image for the to-be-decoded block 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, based on the motion vector for the to-be-decoded block; and a third generator configured to generate a decoded image signal for the to-be-decoded block by calculating a sum of the prediction error signal and the motion compensation prediction image.