US 11,792,430 B2
Method for coding image on basis of secondary transform and device therefor
Moonmo Koo, Seoul (KR); Seunghwan Kim, Seoul (KR); Mehdi Salehifar, Seoul (KR); and Jaehyun Lim, Seoul (KR)
Assigned to LG Electronics Inc., Seoul (KR)
Filed by LG Electronics Inc., Seoul (KR)
Filed on Feb. 15, 2022, as Appl. No. 17/671,788.
Application 17/671,788 is a continuation of application No. 17/327,246, filed on May 21, 2021, granted, now 11,297,347.
Application 17/327,246 is a continuation of application No. PCT/KR2019/017900, filed on Dec. 17, 2019.
Claims priority of provisional application 62/782,285, filed on Dec. 19, 2018.
Prior Publication US 2022/0174319 A1, Jun. 2, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/60 (2014.01); H04N 19/124 (2014.01); H04N 19/159 (2014.01); H04N 19/176 (2014.01); H04N 19/18 (2014.01); H04N 19/70 (2014.01); H04N 19/96 (2014.01)
CPC H04N 19/60 (2014.11) [H04N 19/124 (2014.11); H04N 19/159 (2014.11); H04N 19/176 (2014.11); H04N 19/18 (2014.11); H04N 19/70 (2014.11); H04N 19/96 (2014.11)] 12 Claims
OG exemplary drawing
 
1. An image decoding method performed by a decoding apparatus, the method comprising:
receiving residual information and a transform index from a bitstream;
deriving transform coefficients for a target block based on the residual information;
deriving modified transform coefficients based on an inverse non-separable transform for the transform coefficients; and
deriving residual samples for the target block based on an inverse primary transform for the modified transform coefficients,
wherein the inverse non-separable transform is performed based on a transform kernel matrix related to the transform index among transform kernel matrices included in a transform set,
wherein the transform index is decoded based on a context adaptive binary arithmetic coding (CABAC) and by:
deriving context information of a syntax element for the transform index;
decoding, based on the context information, bins of the syntax element for the transform index, the bins including a first bin and a second bind; and
deriving, based on the decoded bins, a value of the syntax element for the transform index,
wherein (i) based on a tree type of the target block being a dual tree type, the first bin of the syntax element for the transform index is derived based on a first context information, and (ii) based on the tree type of the target block being a single tree type, the first bin of the syntax element for the transform index is derived based on a second context information, and
wherein the first context information and the second context information are different from each other.