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, the each of indexes 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, (c) a flag indicating presence or non-presence of the weighting factor and the offset concerning luminance and (d) 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 reference images by the weighting factors corresponding to the respective reference images and adding the given number of offsets;   generating a prediction error signal by calculating an error between the input video image the prediction image;   generating a quantized orthogonal transform coefficient 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 and (2) the given number of indexes, and encoding the plurality of combinations in units of one or more of the to-be-encoded blocks.   
     
     
         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 block, a given number of indexes, the each of indexes 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, (c) a flag indicating presence or non-presence of the weighting factor and the offset concerning luminance and (d) a flag indicating presence or non-presence of the weighting factor and the offset concerning color differences and (B) a reference image;   a generator configured to generate a prediction image by multiplying the given number of reference images by the weighting factors corresponding to the respective reference images and adding the given number of offsets;   a generator configured to generate a prediction error signal by calculating an error between the input video image the prediction image;   a 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, for the to-be-encoded block, (1) the quantized orthogonal transform coefficient and (2) the given number of indexes, and encoding the plurality of combinations in units of one or more of the to-be-encoded blocks.