Patent ID: 7864855

Claim:
A video encoding method performed by an encoder for subjecting an input video to motion compensation prediction encoding, the input video having a luminance component and first and second color difference components, the video encoding method comprising: determining a given number of reference images and 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; determining the given number of indexes which indicate the determined reference images and combinations respectively; generating a motion compensation prediction image for a to-be-encoded block by multiplying the luminance components and the first and second color difference components of the given number of the reference images respectively by the weighting factors corresponding to the respective reference images and adding the given number of the offsets, respectively, to results of the multiplying, based on motion vectors for the to-be-encoded block; generating a prediction error signal for the to-be-encoded block by obtaining an error between the input video 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, by the encoder, (1) the quantized orthogonal transform coefficient, (2) information of the motion vectors, and (3) the given number of the indexes.