Patent ID: 11909972
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 multiple transform selection (MTS) index and residual information from a bitstream;
deriving quantized transform coefficients for a current block based on the residual information,
deriving transform coefficients for the current block by performing a dequantization on the quantized transform coefficients; and
generating residual samples of the current block by performing an inverse transform on the transform coefficients based on a transform kernel set related to the MTS index,
wherein the MTS index represents the transform kernel set to be applied to the current block among transform kernel set candidates,
wherein the transform kernel set comprises a transform kernel to be applied to the current block in a horizontal direction and a transform kernel to be applied to the current block in a vertical direction,
wherein bins of a bin string of the MTS index are derived based on context coding, the context coding being performed based on values of context index increment for the bins of the bin string of the MTS index,
wherein the bins of the bin string of the MTS index include first, second, third, and fourth bins, and
wherein a value of the context index increment for the first bin is fixed to 0, a value of the context index increment for the second bin is fixed to 1, a value of the context index increment for the third bin is fixed to 2, and a value of the context index increment for the fourth bin is fixed to 3.