Patent ID: 11968397
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:
receiving residual information;
deriving a plurality of first transform coefficients in a top-left 4×4 region of a target block based on the residual information;
deriving a plurality of second transform coefficients based on an inverse secondary transform of the plurality of first transform coefficients;
deriving a two-dimensional array based on the plurality of second transform coefficients, wherein the plurality of second transform coefficients are mapped to a top-left 8×8 region of the two-dimensional array, excluding a bottom-right 4×4 region within the top-left 8×8 region;
deriving an array of residual samples based on an inverse primary transform of the two-dimensional array; and
generating a reconstructed picture based on the array of residual samples.