US 12,088,830 B2
Image coding method on basis of secondary transform and device therefor
Mehdi Salehifar, Seoul (KR); Seunghwan Kim, Seoul (KR); Jaehyun Lim, Seoul (KR); and Moonmo Koo, Seoul (KR)
Assigned to LG ELECTRONICS INC., Seoul (KR)
Filed by LG ELECTRONICS INC., Seoul (KR)
Filed on Jan. 24, 2023, as Appl. No. 18/100,781.
Application 18/100,781 is a division of application No. 18/091,762, filed on Dec. 30, 2022.
Application 18/091,762 is a continuation of application No. 17/568,322, filed on Jan. 4, 2022, granted, now 11,570,452.
Application 17/568,322 is a continuation of application No. 16/954,026, granted, now 11,252,420, issued on Feb. 15, 2022, previously published as PCT/KR2018/015809, filed on Dec. 13, 2018.
Claims priority of provisional application 62/599,022, filed on Dec. 15, 2017.
Prior Publication US 2023/0164332 A1, May 25, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/18 (2014.01); H04N 19/176 (2014.01); H04N 19/184 (2014.01); H04N 19/46 (2014.01); H04N 19/60 (2014.01); H04N 19/91 (2014.01)
CPC H04N 19/18 (2014.11) [H04N 19/176 (2014.11); H04N 19/184 (2014.11); H04N 19/46 (2014.11); H04N 19/60 (2014.11); H04N 19/91 (2014.11)] 4 Claims
OG exemplary drawing
 
1. An image decoding method performed by a decoding apparatus, the decoding method comprising:
acquiring information about transform coefficients for a target block from the bitstream;
deriving transform coefficients for the target block based on the information about the transform coefficients;
deriving residual samples for the target block by performing a predefined inverse transform based on the transform coefficients; and
generating reconstructed samples based on the residual samples, wherein based on a case that the predefined inverse transform is applied, transform coefficients for the target block in a remaining region other than a top-left target region of the target block are equal to 0,
wherein a size of an input target region for the predefined inverse transform is smaller than a size of an output target region for the predefined inverse transform, wherein the input target region is equal to the top-left target region,
wherein the information about the transform coefficients for the target block includes information about a location of a last non-zero transform coefficient, and
wherein based on the case that the predefined inverse transform is applied, the last non-zero transform coefficient is one of transform coefficients other than the transform coefficients in the remaining region.