US 12,284,355 B2
In-loop filtering-based image coding apparatus and method
Junghak Nam, Seoul (KR); and Jangwon Choi, Seoul (KR)
Assigned to LG Electronics Inc., Seoul (KR)
Filed by LG Electronics Inc., Seoul (KR)
Filed on Feb. 13, 2024, as Appl. No. 18/440,778.
Application 18/440,778 is a continuation of application No. 18/098,489, filed on Jan. 18, 2023, granted, now 11,936,875.
Application 18/098,489 is a continuation of application No. 17/682,744, filed on Feb. 28, 2022, granted, now 11,582,457, issued on Feb. 14, 2023.
Application 17/682,744 is a continuation of application No. PCT/KR2020/011597, filed on Aug. 31, 2020.
Claims priority of provisional application 62/893,748, filed on Aug. 29, 2019.
Prior Publication US 2024/0187602 A1, Jun. 6, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/00 (2014.01); H04N 19/117 (2014.01); H04N 19/132 (2014.01); H04N 19/169 (2014.01); H04N 19/176 (2014.01); H04N 19/186 (2014.01); H04N 19/46 (2014.01); H04N 19/80 (2014.01)
CPC H04N 19/132 (2014.11) [H04N 19/117 (2014.11); H04N 19/176 (2014.11); H04N 19/186 (2014.11); H04N 19/1883 (2014.11); H04N 19/46 (2014.11); H04N 19/80 (2014.11)] 3 Claims
OG exemplary drawing
 
1. An image decoding method performed by a decoding apparatus, comprising:
obtaining image information including prediction related information and residual information through a bitstream;
generating prediction samples based on the prediction related information;
deriving quantized transform coefficients based on the residual information;
deriving transform coefficients based on a dequantization process for the quantized transform coefficients;
deriving residual samples based on an inverse transform process for the transform coefficients;
generating reconstructed samples based on the prediction samples and the residual samples, wherein the reconstructed samples include reconstructed luma samples and reconstructed chroma samples;
deriving ALF filter coefficients for an adaptive loop filtering (ALF) process of the reconstructed chroma samples;
generating filtered reconstructed chroma samples based on the reconstructed chroma samples and the ALF filter coefficients;
deriving cross-component filter coefficients for cross-component filtering; and
generating modified filtered reconstructed chroma samples based on the reconstructed luma samples, the filtered reconstructed chroma samples, and the cross-component filter coefficients,
wherein the image information includes a sequence parameter set (SPS), header information and an adaptation parameter set (APS) including ALF data,
wherein the SPS includes a cross-component adaptive loop filter (CCALF) enabled flag related to whether the cross-component filtering is enabled,
wherein the cross-component filter coefficients are derived based on the ALF data,
wherein the header information includes a first flag related to whether the CCALF is enabled for a Cb color component of the filtered reconstructed chroma samples,
wherein based on the determination that a value of the first flag is 1, the header information includes information related to an identifier of the APS for deriving the cross-component filter coefficients for the Cb color component,
wherein the ALF data included in the APS for deriving the cross-component filter coefficients for the Cb color component include a Cb filter signal flag related to whether the cross-component filters for the Cb color component are signaled,
wherein based on the Cb filter signal flag, the ALF data included in the APS for deriving the cross-component filter coefficients for the Cb color component include information related to the number of cross-component filters for the Cb color component,
wherein based on the information related to the number of cross-component filters for the Cb color component, the ALF data included in the APS for deriving the cross-component filter coefficients for the Cb color component include information on absolute values of the cross-component filter coefficients for the Cb color component and information on signs of the cross-component filter coefficients for the Cb color component, and
wherein the cross-component filter coefficients for the Cb color component are derived based on the information on the absolute values of the cross-component filter coefficients for the Cb color component and the information on the signs of the cross-component filter coefficients for the Cb color component.