RU2023133392A - ECODER, DECODER, ENCODING METHOD AND DECODING METHOD - Google Patents

Claims (50)

1. Decoder containing: Memory device; And a processor coupled to a storage device and configured to generate a predictive image to decode a current block based on a first parameter, a second parameter, a third parameter, a fourth parameter and a fifth parameter that are retrieved in a bidirectional optical flow (BDOF)-based process, wherein : the first parameter is retrieved based on the following expression: Mathematical expression 1 ; the second parameter is retrieved based on the following expression: Mathematical expression 2 ; the third parameter is retrieved based on the following expression: Mathematical expression 3 ; the fourth parameter is retrieved based on the following expression: Mathematical expression 4 ; And the fifth parameter is extracted based on the following expression, Mathematical expression 5 , Where Ω indicates a set of relative pixel positions; [i, j] indicates a relative pixel position in the set Ω, specified by the horizontal position i and the vertical position j; I _x ⁰ indicates a horizontal gradient value at a first pixel position in the first gradient image, and I _x ¹ indicates a horizontal gradient value at a first pixel position in the second gradient image, wherein the first pixel position is determined based on the relative pixel position [i, j] of the first a gradient image and a second gradient image corresponding to the current block; I _y ⁰ indicates a vertical gradient value at a first pixel position in the first gradient image, and I _y ¹ indicates a vertical gradient value at a first pixel position in the second gradient image; I ⁰ indicates a pixel value at the first pixel position in the first interpolated image corresponding to the current block; I ¹ indicates a pixel value at a first pixel position in the second interpolated image corresponding to the current block; the abs function prints the absolute value of the argument; And The sign function prints the sign of the argument, which is -1, 0, or 1. 2. A non-transitory computer-readable recording medium storing a bit stream, wherein the bit stream includes a prediction parameter that specifies a prediction process from among possible prediction process options and which is read by a decoder to decode a current block represented in the bit stream, wherein possible prediction process options include itself a bidirectional optical flow (BDOF) process in which a first parameter, a second parameter, a third parameter, a fourth parameter and a fifth parameter are used to generate a predictive image of the current block, wherein the first parameter is retrieved based on the following expression: Mathematical expression 1 ; the second parameter is retrieved based on the following expression: Mathematical expression 2 ; the third parameter is retrieved based on the following expression: Mathematical expression 3 ; the fourth parameter is retrieved based on the following expression: Mathematical expression 4 ; And the fifth parameter is extracted based on the following expression: Mathematical expression 5 , Where Ω indicates a set of relative pixel positions; [i, j] indicates a relative pixel position in the set Ω, specified by the horizontal position i and the vertical position j; I _x ⁰ indicates a horizontal gradient value at a first pixel position in the first gradient image, and I _x ¹ indicates a horizontal gradient value at a first pixel position in the second gradient image, wherein the first pixel position is determined based on the relative pixel position [i, j] of the first a gradient image and a second gradient image corresponding to the current block; I _y ⁰ indicates a vertical gradient value at a first pixel position in the first gradient image, and I _y ¹ indicates a vertical gradient value at a first pixel position in the second gradient image; I ⁰ indicates a pixel value at a first pixel position in the first interpolated image corresponding to the current block; I ¹ indicates a pixel value at a first pixel position in the second interpolated image corresponding to the current block; the abs function prints the absolute value of the argument; And The sign function prints the sign of the argument, which is -1, 0, or 1.