Patent ID: 11871035
Assignee: LG ELECTRONICS INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
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.