Patent ID: 7869512

Claim:
A video encoding method for subjecting an input video image to motion compensation predictive encoding, the input video image having a luminance component and first and second color difference components, the method comprising: determining an index indicating one combination of 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, and (G) a flag indicating presence or non-presence of the weighting factor and the offset for the luminance component; generating a motion compensation prediction image for a to-be-encoded 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 a motion vector; generating a prediction error signal for the to-be-encoded block by calculating an error between the input video image and the motion compensation prediction image; generating a quantized orthogonal transform coefficient for the to-be-encoded block by subjecting the prediction error signal to orthogonal transform and quantization; and encoding, for the to-be-encoded block, (1) the quantized orthogonal transform coefficient, (2) information of the motion vector and (3) the index, and encoding, for one or more to-be-encoded blocks, the plurality of combinations.