US 12,425,613 B2
Image decoding apparatus and image coding apparatus
Tianyang Zhou, Sakai (JP); Tomohiro Ikai, Sakai (JP); Eiichi Sasaki, Sakai (JP); and Tomoko Aono, Sakai (JP)
Assigned to SHARP KABUSHIKI KAISHA, Sakai (JP)
Appl. No. 18/267,794
Filed by Sharp Kabushiki Kaisha, Sakai (JP)
PCT Filed Dec. 14, 2021, PCT No. PCT/JP2021/045993
§ 371(c)(1), (2) Date Jun. 16, 2023,
PCT Pub. No. WO2022/131243, PCT Pub. Date Jun. 23, 2022.
Claims priority of application No. 2020-209914 (JP), filed on Dec. 18, 2020.
Prior Publication US 2024/0107033 A1, Mar. 28, 2024
Int. Cl. H04N 19/18 (2014.01); H04N 19/124 (2014.01); H04N 19/184 (2014.01); H04N 19/30 (2014.01); H04N 19/60 (2014.01); H04N 19/70 (2014.01)
CPC H04N 19/18 (2014.11) [H04N 19/124 (2014.11); H04N 19/184 (2014.11); H04N 19/30 (2014.11); H04N 19/60 (2014.11); H04N 19/70 (2014.11)] 5 Claims
OG exemplary drawing
 
1. An image decoding apparatus comprising:
a scaling circuit that derives a scaled transform coefficient by clipping a first value by a minimum value and a maximum value, wherein the minimum value and the maximum value are derived by using a first range value and the first value is derived by using (i) a product of a transform coefficient and a scaling parameter and (ii) a right-shift operation by a first shift value;
an inverse transform processing circuit that derives an intermediate coefficient obtained by (i) transforming the scaled transform coefficient and (ii) clipping by the minimum value and the maximum value and that derives a residual by transforming the intermediate coefficient and right-shifting by a second shift value; and
a transport unit (TU) decoder that decodes a syntax element representing an absolute value of the transform coefficient, in which a suffix part of the absolute value is decoded by using a variable maxPreExtLen equal to 26 minus the first range value,
wherein
the first shift value and the second shift value are derived by using a value of a first bit-depth,
the first range value is set to a minimum value of (i) a sum of a value of the first bit-depth and 6 and (ii) a constant value equal to 20, in a case that a value of an extension flag is true, and
the extension flag specifies whether an extended range is used.