Patent ID: 7869511

Claim:
A video decoding apparatus for decoding encoded data obtained by subjecting a video image to predictive 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 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, and (f) a third offset for the second color difference component, and (g) a flag indicating presence or non-presence of the weighting factor and the offset for the luminance component and encoding, for a to-be-decoded block, (1) a quantized orthogonal transform coefficient of a prediction error signal relating to the luminance component and the first and second color difference components and (2) an index indicating a combination selected from the plurality of combinations; a deriving module derive, for the to-be-decoded block, a combination comprising the weighting factors and the factors 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 transform coefficient to inverse quantization and inverse orthogonal transform; a second generator configured to generate a 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; 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 prediction image.