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 decoding method for decoding encoded data generated by encoding a video image having luminance and two color differences, comprising:
 a step of receiving encoded data obtained by encoding, in units of one or more to-be-decoded block, 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 encoding, for every to-be-decoded block, (1) a quantized orthogonal transform coefficient of a prediction error signal concerning luminance and two color differences and (2) a given number of index information each indicating (a) one of the plurality of combinations and (b) a reference image;   a step of deriving, for every to-be-decoded block, a given number of combinations each having the weighting factor and the offset from the given number of index information and the plurality of combinations;   a step of generating a prediction image every to-be-decoded block by multiplying a given number of reference images by a given number of weighting factors corresponding to respective reference images and then adding the given number of offsets to multiplication results;   a step of generating a prediction error signal every to-be-decoded block by subjecting the quantized orthogonal transform coefficient to inverse quantization and inverse orthogonal transform; and   a step of generating a decoded image signal every to-be-decoded block by calculating a sum of the prediction error signal and the prediction image.   
     
     
         2 . A video decoding method for decoding encoded data generated by encoding a video image having luminance and two color differences, comprising:
 means for receiving encoded data obtained by encoding, in units of one or more to-be-decoded block, 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 encoding, for every to-be-decoded block, (1) a quantized orthogonal transform coefficient of a prediction error signal concerning luminance and two color differences and (2) a given number of index information each indicating (a) one of the plurality of combinations and (b) a reference image;   means for deriving, for every to-be-decoded block, a given number of combinations each having the weighting factor and the offset from the given number of index information and the plurality of combinations;   means for generating a prediction image every to-be-decoded block by multiplying a given number of reference images by a given number of weighting factors corresponding to respective reference images and then adding the given number of offsets to multiplication results;   means for generating a prediction error signal every to-be-decoded block by subjecting the quantized orthogonal transform coefficient to inverse quantization and inverse orthogonal transform; and   means for generating a decoded image signal every to-be-decoded block by calculating a sum of the prediction error signal and the prediction image.