Patent ID: 11889080
Assignee: LG ELECTRONICS INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A method for reconstructing a video signal, the method comprising:
obtaining a secondary transform index for a current block;
deriving a secondary transform matrix related to a specific area in a transform block based on the secondary transform index, wherein the specific area represents an area including a top-left area of the transform block, and wherein the secondary transform matrix is denoted based on an input length and an output length of a secondary transform;
performing an inverse secondary transform for the specific area based on the secondary transform matrix;
performing an inverse primary transform for a block which the inverse secondary transform is applied to;
obtaining residual samples based on a block which the primary inverse transform is applied to; and
reconstructing the current block based on the residual samples and prediction samples,
wherein the input length of the inverse secondary transform is determined as 16, and the output length of the inverse secondary transform is determined as 48, based on that each of the height and the width of the transform block is equal to 8 or 16.