US 12,355,948 B2
Method and apparatus for processing video signal by skipping inverse-transform
Bae Keun Lee, Gyeonggi-do (KR)
Assigned to KT CORPORATION, Gyeonggi-do (KR)
Filed by KT CORPORATION, Gyeonggi-do (KR)
Filed on Mar. 12, 2024, as Appl. No. 18/602,300.
Application 18/602,300 is a continuation of application No. 17/974,962, filed on Oct. 27, 2022, granted, now 11,962,762.
Application 17/974,962 is a continuation of application No. 16/982,760, granted, now 11,516,462, issued on Nov. 29, 2022, previously published as PCT/KR2019/003591, filed on Mar. 27, 2019.
Claims priority of application No. 10-2018-0035303 (KR), filed on Mar. 27, 2018.
Prior Publication US 2024/0223749 A1, Jul. 4, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/105 (2014.01); H04N 19/129 (2014.01); H04N 19/174 (2014.01); H04N 19/176 (2014.01)
CPC H04N 19/105 (2014.11) [H04N 19/129 (2014.11); H04N 19/174 (2014.11); H04N 19/176 (2014.11)] 7 Claims
OG exemplary drawing
 
1. A method of decoding a video signal, the method comprising:
determining whether at least one non-zero residual coefficient is included in a current transform block;
decoding residual coefficients of the current transform block;
performing an inverse-quantization for the current transform block;
determining whether an inverse-transform is skipped for the current transform block or not;
obtaining residual samples of the current transform block by performing or skipping the inverse-transform for the current transform block; and
obtaining reconstruction samples by summing the residual samples and prediction samples,
wherein the residual coefficients in the current transform block are decoded in a unit of a sub-block,
wherein a size of the sub-block is determined based on whether at least one of a width or a height of the current transform block is less than 4,
wherein in response that at least one of the width or the height of the current transform block is less than 4, the size of the sub-block is determined as 2×2, 2×8, or 8×2,
wherein in response that both the width and the height of the current block are equal to or greater than 4, the size of the sub-block is determined as 4×4,
wherein whether a transform skip flag, indicating whether the inverse-transform is skipped or not, of the current transform block is present in a bitstream or not is determined based on whether a coding block, including the current transform block, is partitioned into a plurality of transform blocks in a horizontal direction or a vertical direction, and
wherein in response that the current transform block is one of the plurality of transform blocks generated by partitioning the coding block in the horizontal direction or the vertical direction, the transform skip flag of the current transform block is not present in the bitstream, and skipping the inverse-transform is not allowed for the current transform block.