US 12,289,449 B2
Method and apparatus for transform-based image encoding/decoding
Sung Chang Lim, Daejeon (KR); Jung Won Kang, Daejeon (KR); Hyun Suk Ko, Daejeon (KR); Jin Ho Lee, Daejeon (KR); Ha Hyun Lee, Seoul (KR); Dong San Jun, Daejeon (KR); Seung Hyun Cho, Daejeon (KR); Hui Yong Kim, Daejeon (KR); Jin Soo Choi, Daejeon (KR); Yung Lyul Lee, Seoul (KR); Nam Uk Kim, Seoul (KR); and Jun Woo Choi, Seoul (KR)
Assigned to Electronics and Telecommunications Research Institute, Daejeon (KR); and Industry Academy Cooperation Foundation of Sejong University, Seoul (KR)
Filed by Electronics and Telecommunications Research Institute, Daejeon (KR); and Industry Academy Cooperation Foundation of Sejong University, Seoul (KR)
Filed on Jul. 26, 2023, as Appl. No. 18/359,384.
Application 18/359,384 is a continuation of application No. 16/302,210, granted, now 11,758,136, previously published as PCT/KR2017/006645, filed on Jun. 23, 2017.
Claims priority of application No. 10-2016-0079630 (KR), filed on Jun. 24, 2016; application No. 10-2016-0163688 (KR), filed on Dec. 2, 2016; and application No. 10-2017-0031741 (KR), filed on Mar. 14, 2017.
Prior Publication US 2023/0379466 A1, Nov. 23, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/122 (2014.01); H04N 19/103 (2014.01); H04N 19/107 (2014.01); H04N 19/132 (2014.01); H04N 19/176 (2014.01); H04N 19/186 (2014.01); H04N 19/61 (2014.01); H04N 19/625 (2014.01); H04N 19/70 (2014.01); H04N 19/90 (2014.01)
CPC H04N 19/122 (2014.11) [H04N 19/103 (2014.11); H04N 19/107 (2014.11); H04N 19/132 (2014.11); H04N 19/176 (2014.11); H04N 19/186 (2014.11); H04N 19/61 (2014.11); H04N 19/625 (2014.11); H04N 19/70 (2014.11); H04N 19/90 (2014.11)] 11 Claims
OG exemplary drawing
 
1. A method for decoding a video, the method comprising:
obtaining, from a bitstream, a coded block flag indicating whether a non-zero transform coefficient exists for a current block;
obtaining transform coefficients from the bitstream based on the coded block flag to thereby generate a coefficient block for the current block;
obtaining transform mode information of the current block from the bitstream;
determining a transform type of the current block based on the transform mode information; and
inverse-transforming the coefficient block according to the transform type of the current block,
wherein the transform mode information is index information for indicating a transform type of the current block among predefined transform types,
wherein the transform mode information is obtained only when the coded block flag indicates the non-zero transform coefficient exists for the current block,
wherein the transform mode information is obtained from the bitstream only when a larger value among a width and a height of the current block is less than or equal to a predetermined size, and
wherein the transform mode information is not obtained from the bitstream when only one non-zero transform coefficient exists in the coefficient block and is located at a top left corner in the coefficient block.