US 11,871,035 B2
Image coding method on basis of transform, and apparatus therefor
Moonmo Koo, Seoul (KR); Seunghwan Kim, Seoul (KR); and Jaehyun Lim, Seoul (KR)
Assigned to LG ELECTRONICS INC., Seoul (KR)
Filed by LG Electronics Inc., Seoul (KR)
Filed on Dec. 14, 2022, as Appl. No. 18/081,297.
Application 18/081,297 is a continuation of application No. 17/700,271, filed on Mar. 21, 2022, granted, now 11,563,979.
Application 17/700,271 is a continuation of application No. PCT/KR2020/012655, filed on Sep. 18, 2020.
Claims priority of provisional application 62/903,826, filed on Sep. 21, 2019.
Prior Publication US 2023/0122409 A1, Apr. 20, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/61 (2014.01); H04N 19/176 (2014.01); H04N 19/18 (2014.01); H04N 19/186 (2014.01)
CPC H04N 19/61 (2014.11) [H04N 19/176 (2014.11); H04N 19/18 (2014.11); H04N 19/186 (2014.11)] 3 Claims
OG exemplary drawing
 
1. A decoding apparatus for image decoding, the decoding apparatus comprising:
a memory; and
at least one processor connected to the memory, the at least one processor configured to:
receive a bitstream including residual information;
derive transform coefficients for a current block based on the residual information;
derive modified transform coefficients by applying a low-frequency non-separable transform (LFNST) to the transform coefficients; and
derive residual samples for the current block based on an inverse primary transform for the modified transform coefficients,
wherein the at least one processor further configured to
determine whether or not to parse an LFNST index based on whether or not a width and a height of the current block satisfy a condition that the LFNST is applied,
wherein whether or not the condition that the LFNST is applied is satisfied is determined based on a tree-type of the current block, a color format of the current block, and whether or not an intra sub partitions (ISP) is applied to the current block, and
wherein in case the ISP is applied, based on the width and the height of the current block corresponding to a subpartition block being equal to 4 or more, the LFNST index is parsed.