US 12,294,711 B2
Method of determining transform coefficient scan order based on high frequency zeroing and apparatus thereof
Jungah Choi, Seoul (KR); Seunghwan Kim, Seoul (KR); Jin Heo, Seoul (KR); Sunmi Yoo, Seoul (KR); Ling Li, Seoul (KR); and Jangwon Choi, Seoul (KR)
Assigned to VIVO MOBILE COMMUNICATION CO., LTD., Guangdong (CN)
Filed by VIVO MOBILE COMMUNICATION CO., LTD., Guangdong (CN)
Filed on Oct. 24, 2023, as Appl. No. 18/383,327.
Application 18/383,327 is a continuation of application No. 16/855,785, filed on Apr. 22, 2020, granted, now 11,838,512.
Application 16/855,785 is a continuation of application No. PCT/KR2019/017723, filed on Dec. 13, 2019.
Claims priority of provisional application 62/780,925, filed on Dec. 17, 2018.
Claims priority of provisional application 62/792,826, filed on Jan. 15, 2019.
Prior Publication US 2024/0056579 A1, Feb. 15, 2024
Int. Cl. H04N 19/132 (2014.01); H04N 19/129 (2014.01); H04N 19/176 (2014.01); H04N 19/46 (2014.01); H04N 19/60 (2014.01)
CPC H04N 19/132 (2014.11) [H04N 19/129 (2014.11); H04N 19/176 (2014.11); H04N 19/46 (2014.11); H04N 19/60 (2014.11)] 3 Claims
OG exemplary drawing
 
1. An image decoding method performed by a decoding apparatus, the method comprising:
receiving a bitstream including residual information;
obtaining last significant coefficient related information based on the residual information;
deriving transform coefficients for a current block based on the last significant coefficient related information;
deriving residual samples for the current block from the transform coefficients based on an inverse transform; and
generating a reconstructed picture based on the residual samples for the current block,
wherein the current block includes a first region and a second region,
wherein the first region is a region related to a last significant coefficient, and the second region is a region different from the first region in the current block,
wherein the last significant coefficient related information includes:
a last_sig_coeff_x_prefix syntax element related to an x component of a position of the last significant coefficient of the current block,
a last_sig_coeff_y_prefix syntax element related to an y component of a position of the last significant coefficient of the current block,
wherein the last_sig_coeff_x_prefix syntax element is based on truncated rice binarization,
wherein the last_sig_coeff_y_prefix syntax element is based on truncated rice binarization,
wherein based on both a transform block width and a transform block height of the current block being equal to 64,
a width of the first region is determined as 32,
a height of the first region is determined as 32,
a maximum length of a codeword for the last_sig_coeff_x_prefix syntax element is determined as 9 for the transform block width of the current block being equal to 64 based on a determination that the width of the first region is 32,
a maximum length of a codeword for the last_sig_coeff_y_prefix syntax element is determined as 9 for the transform block height of the current block being equal to 64 based on a determination that the height of the first region is 32,
wherein transform coefficient subblock scanning is performed for the current block based on diagonal direction within the first region, and
wherein with regard to the current block, coded subblock flags for subblocks located outside of the first region are not included in the residual information.