US 11,659,205 B2
Method of coding transform coefficient based on high frequency zeroing and apparatus thereof
Jungah Choi, Seoul (KR); Sunmi Yoo, Seoul (KR); Jin Heo, Seoul (KR); Ling Li, Seoul (KR); Jangwon Choi, Seoul (KR); and Seunghwan Kim, Seoul (KR)
Assigned to LG Electronics Inc., Seoul (KR)
Filed by LG ELECTRONICS INC., Seoul (KR)
Filed on Nov. 30, 2021, as Appl. No. 17/537,813.
Application 17/537,813 is a continuation of application No. 17/148,970, filed on Jan. 14, 2021, granted, now 11,218,733.
Application 17/148,970 is a continuation of application No. 16/841,062, filed on Apr. 6, 2020, granted, now 10,958,939, issued on Mar. 23, 2021.
Application 16/841,062 is a continuation of application No. PCT/KR2019/015330, filed on Nov. 12, 2019.
Claims priority of provisional application 62/792,824, filed on Jan. 15, 2019.
Claims priority of provisional application 62/760,033, filed on Nov. 12, 2018.
Prior Publication US 2022/0086491 A1, Mar. 17, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/64 (2014.01); H04N 19/124 (2014.01); H04N 19/13 (2014.01); H04N 19/176 (2014.01); H04N 19/70 (2014.01); H04N 19/91 (2014.01); H04N 19/513 (2014.01); H04N 19/61 (2014.01)
CPC H04N 19/647 (2014.11) [H04N 19/124 (2014.11); H04N 19/13 (2014.11); H04N 19/176 (2014.11); H04N 19/70 (2014.11); H04N 19/91 (2014.11); H04N 19/513 (2014.11); H04N 19/619 (2014.11); H04N 19/64 (2014.11)] 14 Claims
OG exemplary drawing
 
1. An image decoding method, by a decoding apparatus, comprising:
deriving quantized transform coefficients for a current block based on residual information received from a bistream;
deriving dequantized transform coefficients for the current block based on the quantized transform coefficient;
deriving residual samples for the current block based on the dequantized transform coefficients; and
generating a reconstructed picture based on the residual samples for the current block,
wherein the current block includes a low frequency transform coefficient region including at least one significant transform coefficient and a region except the low frequency transform coefficient region including only transform coefficient 0,
wherein the residual information includes last significant coefficient prefix information on position of last non-zero transform coefficient among the transform coefficients for the current block,
wherein the last significant coefficient prefix information includes a column position prefix information and a row position prefix information,
wherein the position of the last non-zero transform coefficient is determined based on prefix codewords related to the last significant coefficient prefix information,
wherein the prefix codewords include a codeword for the column position prefix information and a codeword for the row position prefix information, and
wherein a maximum value of the last significant coefficient prefix information and a maximum length of the prefix codewords are determined based on a size of the low frequency transform coefficient region.