ENCODER, DECODER AND RELATED METHODS OF INTERFRAME PREDICTION Russian patent published in 2023 - IPC H04N19/587 H04N19/503 H04N19/54 

FIELD: video encoding/decoding.

SUBSTANCE: invention relates to interframe prediction. A method for bidirectional optical flow prediction is proposed, which contains the stages of: obtaining an initial pair of motion vectors for the current block, obtaining a forward and backward prediction block corresponding to the forward motion vector, and a reverse prediction block corresponding to the initial pair of motion vectors; calculating the gradient parameters for the current sample in the current block; obtaining at least two optical flow sample parameters comprising a first parameter and a second parameter for the current sample based on the gradient parameters; obtaining parameters of an optical flow block based on parameters of the optical flow samples in the current block, where one of the parameters of the optical flow block is obtained by multiplying the value of the first parameter and the value of a sign function of the second parameter, and where the sign function is a piecewise function with at least three sub-bands; and obtaining the prediction value of the current block.

EFFECT: increase in the compression ratio with minimal or no overhead in image quality.

19 cl, 14 dwg