Patent ID: 11889071
Assignee: LG ELECTRONICS INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. An image decoding method performed by a decoding apparatus, the method comprising:
obtaining image information including prediction related information, residual information and adaptive loop filter (ALF) information from a bitstream;
deriving prediction samples of a current block based on the prediction related information;
deriving residual samples of the current block based on the residual information;
generating reconstructed samples of the current block based on the prediction samples and the residual samples;
deriving filter coefficients for an ALF based on the ALF information; and
performing an adaptive loop filter (ALF) process on the reconstructed samples to generated modified reconstructed samples of the current block based on the filter coefficients,
wherein the image information includes index information of an alternative filter for a chroma component of the current block,
wherein the ALF information includes alternative filter information for the chroma component of the current block including information on a number of alternative filters for the chroma component of the current block,
wherein based on the information on the number of the alternative filters for the chroma component of the current block, the alternative filter information includes absolute value information of coefficients included in alternative filters for the chroma component of the current block and sign information of coefficients included in the alternative filters for the chroma component of the current block,
wherein the index information of the alternative filter is based on truncated rice binarization,
wherein bins of a bin string for the index information of the alternative filter are entropy-decoded based on a context model,
wherein the context model for the bins of the bin string related to the index information of the alternative filter is determined based on a context index increment for the bins, and
wherein the context index increment is determined based on the chroma component of the current block.