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 predictive encoding, comprising:
 a step of obtaining, for every to-be-encoded block of the input video image, a plurality of index information elements indicating (1) one of a plurality of combinations each including (A) a weighting factor every luminance and two color differences and (B) an offset every luminance and two color differences, and (2) a reference image;   a step of generating a prediction image every to-be-encoded block by multiplying a given number of reference images by the weighting factor corresponding to each reference image and then adding a given number of offsets to multiplication results;   a step of generating a prediction error signal every to-be-encoded block by calculating an error between the input video image and the prediction image;   a step of generating a quantized orthogonal transform coefficient every to-be-encoded block by subjecting the prediction error signal to orthogonal transform and quantization; and   a step of encoding, for every to-be-encoded block, (1) the quantized orthogonal transform coefficient and (2) a given number of index information, and encoding the plurality of combinations in units of one or more to-be-encoded blocks.   
     
     
         2 . A video encoding apparatus of subjecting an input video image having luminance and two color differences to predictive encoding, comprising:
 means for obtaining, for every to-be-encoded block of the input video image, a plurality of index information elements indicating (1) one of a plurality of combinations each including (A) a weighting factor every luminance and two color differences and (B) an offset every luminance and two color differences, and (2) a reference image;   means for generating a prediction image every to-be-encoded block by multiplying a given number of reference images by the weighting factor corresponding to each reference image and then adding a given number of offsets to multiplication results;   means for generating a prediction error signal every to-be-encoded block by calculating an error between the input video image and the prediction image;   means for generating a quantized orthogonal transform coefficient every to-be-encoded block by subjecting the prediction error signal to orthogonal transform and quantization; and   means for encoding, for every to-be-encoded block, (1) the quantized orthogonal transform coefficient and (2) a given number of index information, and encoding the plurality of combinations in units of one or more to-be-encoded blocks.