Video encoding/decoding method and apparatus

Abstract

A video encoding method comprises selecting one combination, for each block of an input video signal, from a plurality of combinations each including a predictive parameter and at least one reference picture number determined in advance for the reference picture, generating a prediction picture signal in accordance with the reference picture number and predictive parameter of the selected combination, generating a predictive error signal representing an error between the input video signal and the prediction picture signal, and encoding the predictive error signal, information of the motion vector, and index information indicating the selected combination.

1 . A video encoding method for subjecting an input video image having luminance and two color differences to prediction encoding, comprising:
 obtaining, for a to-be-encoded block, a given number of indexes each indicating (A) one combination of a plurality of combinations comprising (a) a weighting factor every luminance and two color differences, (b) an offset every luminance and two color differences and (c) a flag indicating presence or non-presence of the weighting factor and the offset concerning color differences and (B) a reference image;   generating a prediction image by multiplying the given number of the reference images by weighting factors corresponding to the reference images and adding the given number of the offsets;   generating a prediction error signal by calculating an error between the input video image and the prediction image;   generating a quantized orthogonal transform coefficient by subjecting the prediction error signal to orthogonal transform and quantization; and   encoding, the to-be-encoded block, (1) the quantized orthogonal transform coefficient and (2) the given number of indexes, and encoding, for one or more to-be-encoded blocks, the plurality of combinations;   wherein two values of the indexes corresponding to the different reference images respectively indicate an identical combination of the weighting factor and the offset.   
     
     
         2 . A video encoding apparatus of subjecting an input video image having luminance and two color differences to prediction encoding, comprising:
 an obtaining module configured to obtain, for a to-be-encoded blocks, a given number of indexes each indicating (A) one combination of a plurality of combinations comprising (a) a weighting factor every luminance and two color differences, (b) an offset every luminance and two color differences and (c) a flag indicating presence or non-presence of the weighting factor and the offset concerning color differences and (B) a reference image;   a first generator configured to generate a prediction image by multiplying the given number of the reference images by weighting factors corresponding to the reference images and adding the given number of the offsets;   a second generator configured to generate a prediction error signal by calculating an error between the input video image and the prediction image;   a third generator configured to generate a quantized orthogonal transform coefficient by subjecting the prediction error signal to orthogonal transform and quantization; and   an encoder configured to encode, the to-be-encoded block, (1) the quantized orthogonal transform coefficient and (2) the given number of indexes, and encode, for one or more to-be-encoded blocks, the plurality of combinations;   wherein two values of the indexes corresponding to the different reference images respectively indicate an identical combination of the weighting factor and the offset.