Patent ID: 11902582
Assignee: LG ELECTRONICS INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A decoding apparatus of decoding an image, comprising:
a memory; and
at least one processor connected to the memory, the at least one processor configured to:
derive quantized transform coefficients for a current block based on residual information received from a bitstream;
derive dequantized transform coefficients for the current block based on the quantized transform coefficient;
derive residual samples for the current block based on the dequantized transform coefficients; and
generate a reconstructed picture based on the residual samples for the current block,
wherein the current block includes a low frequency transform coefficient region including at least one non-zero transform coefficient and a region including only zero transform coefficients other than the low frequency transform coefficient region,
wherein the residual information includes last significant coefficient prefix information on a position of a last non-zero transform coefficient among the transform coefficients for the current block,
wherein the last significant coefficient prefix information includes column position prefix information and row position prefix information,
wherein the position of the last non-zero transform coefficient is determined based on prefix codewords related to the last significant coefficient prefix information,
wherein the prefix codewords include a first codeword for the column position prefix information and a second codeword for the row position prefix information, and
wherein a maximum value of the last significant coefficient prefix information and a maximum length of the prefix codewords are determined based on a size of the low frequency transform coefficient region.