IMAGE CODING METHOD, IMAGE DECODING METHOD, IMAGE CODING DEVICE, IMAGE DECODING DEVICE AND IMAGE CODING AND DECODING DEVICE Russian patent published in 2023 - IPC H03M7/40 H04N19/169 

FIELD: computer engineering.

SUBSTANCE: technical result is achieved by performing arithmetic coding on the first flag, which indicates whether the absolute value of the target coefficient in the block of target coefficients is greater than 1; and performing arithmetic coding on a second flag that indicates whether the absolute value is greater than 2. In the first flag arithmetic coding and the second flag arithmetic coding, it is determined whether the immediately preceding coefficient block that was encoded immediately before the target coefficient block includes a coefficient having an absolute value greater than a threshold value. Based on the result of the determination, appropriate contexts are selected for use in arithmetic coding on the first and second flags.

EFFECT: increase in the bit rate of image coding.

7 cl, 58 dwg