Patent ID: 7860163

Claim:
A video decoding method 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: receiving 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 and the first and second color difference components, and (B) an index indicating a combination selected from 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 (C) a reference image; deriving the weighting factor and the offset from the index for the to-be-decoded block; generating a prediction image by multiplying the luminance and color difference components of the reference image by the weighting factors, respectively, and adding the offsets, respectively, to results of the multiplying; generating a prediction error signal by subjecting the quantized orthogonal transform coefficient to inverse quantization and inverse orthogonal transform; and generating 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.