US 11,956,434 B2
Encoder, decoder, encoding method, and decoding method
Yusuke Kato, Osaka (JP); Kiyofumi Abe, Osaka (JP); Takahiro Nishi, Nara (JP); and Tadamasa Toma, Osaka (JP)
Assigned to PANASONIC INTELLECTUAL PROPERTY CORPORATION OF AMERICA, Torrance, CA (US)
Filed by Panasonic Intellectual Property Corporation of America, Torrance, CA (US)
Filed on Dec. 6, 2022, as Appl. No. 18/062,335.
Application 18/062,335 is a continuation of application No. 17/865,119, filed on Jul. 14, 2022, granted, now 11,546,598.
Application 17/865,119 is a continuation of application No. 17/173,024, filed on Feb. 10, 2021, granted, now 11,425,385, issued on Aug. 23, 2022.
Application 17/173,024 is a continuation of application No. PCT/JP2019/037618, filed on Sep. 25, 2019.
Claims priority of provisional application 62/738,399, filed on Sep. 28, 2018.
Prior Publication US 2023/0095404 A1, Mar. 30, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/13 (2014.01); H04N 19/169 (2014.01); H04N 19/176 (2014.01); H04N 19/46 (2014.01)
CPC H04N 19/13 (2014.11) [H04N 19/176 (2014.11); H04N 19/46 (2014.11); H04N 19/1887 (2014.11)] 3 Claims
OG exemplary drawing
 
1. An encoder comprising:
memory; and
a processor coupled to the memory and which, in operation, performs Context-Based Adaptive Binary Arithmetic Coding (CABAC), wherein
in prediction residual coding of a current block, the processor, in operation,
encodes a plurality of flags by CABAC, each of the plurality of flags relating to a coefficient included in the current block;
determines a base level;
calculates a prediction absolute value of the coefficient based on a sum of absolute values of five neighboring coefficients of the coefficient in the current block;
derives a rice parameter based on a difference between the prediction absolute value and the base level, wherein
if the difference is below a first value, the rice parameter is set to zero, and
if the difference is equal to or larger than the first value and smaller than a second value, the rice parameter is set to one:
encodes a remainder value of the coefficient using the derived rice parameter, wherein the remainder value is obtained by using an absolute value of the coefficient and the base level; and
encodes a sign flag indicating whether the coefficient has a positive value or a negative value if the absolute value of the coefficient is more than zero.