Patent ID: 7881381
Filing Date: 2011-02-01
Classification: H04N

Abstract:
1. A prediction image generation method performed by a decoder for generating a prediction image from encoded data obtained by subjecting a video image to prediction encoding, the video image having a luminance component and first and second color difference components, the method comprising: receiving an input of encoded data obtained by encoding, for one or more of to-be-decoded blocks, a plurality of combinations each comprising (1) a first weighting factor for the luminance component, (2) a second weighting factor for the first color difference component, (3) a third weighting factor for the second color difference component, (4) a first offset for the luminance component, (5) a second offset for the first color difference component, (6) a third offset for the second color difference component, and (7) a flag indicating presence or non-presence of the weighting factor and offset concerning the luminance component, and encoding, for a to-be-decoded block, (A) information of a motion vector and (B) an index indicating (a) a combination selected from the plurality of combinations and (b) a reference image; deriving, for the to-be-decoded block, the weighting factors and the offsets from the index and the plurality of combinations; and generating, by the decoder, a prediction image by multiplying the luminance component and the 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, based on the motion vector.