Patent ID: 7852918

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, comprising: a receiver configured to receive an input of encoded data obtained by encoding, for a to-be-decoded block, (A) a quantized orthogonal transform coefficient of a prediction error signal concerning the luminance component, the first and second color difference components, and (B) an index indicating (1) a combination selected from a plurality of combinations, each combination comprising (a) a first weighting factor for the luminance component and (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 (2) a reference image; a deriving module configured to derive the weighting factors and the offsets from the index for the to-be-decoded block; a first generator configured to generate a prediction image by multiplying the luminance and 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; a second generator configured to generate a prediction error signal by subjecting the quantized orthogonal transform coefficient to inverse quantization and inverse orthogonal transform; and a third generator configured to generate a decoded image signal by calculating a sum of the prediction error signal and the prediction image; wherein the weighting factors and the offsets derived from two indices which correspond to different reference images, respectively, are identical.