US 12,273,538 B2
Method and apparatus for coding/decoding image
Hui Yong Kim, Daejeon (KR); Sung Chang Lim, Daejeon (KR); Jin Ho Lee, Daejeon (KR); Jin Soo Choi, Daejeon (KR); Jin Woong Kim, Daejeon (KR); Gwang Hoon Park, Seongnam-si (KR); and Kyung Yong Kim, Suwon-si (KR)
Assigned to Electronics and Telecommunications Research Institute, Daejeon (KR); and University-Industry Cooperation Group of Kyung Hee University, Yongin-si (KR)
Filed by Hui Yong Kim, Daejeon (KR); Sung Chang Lim, Daejeon (KR); Jin Ho Lee, Daejeon (KR); Jin Soo Choi, Daejeon (KR); Jin Woong Kim, Daejeon (KR); Gwang Hoon Park, Seongnam-si (KR); and Kyung Yong Kim, Suwon-si (KR)
Filed on Aug. 2, 2019, as Appl. No. 16/530,463.
Application 16/530,463 is a continuation of application No. 16/023,983, filed on Jun. 29, 2018, granted, now 10,419,765.
Application 16/023,983 is a continuation of application No. 15/802,824, filed on Nov. 3, 2017, granted, now 10,045,031, issued on Aug. 7, 2018.
Application 15/802,824 is a continuation of application No. 14/412,316, granted, now 9,843,809, issued on Dec. 12, 2017, previously published as PCT/KR2013/005864, filed on Jul. 2, 2013.
Claims priority of application No. 10-2012-0071938 (KR), filed on Jul. 2, 2012; and application No. 10-2013-0077047 (KR), filed on Jul. 2, 2013.
Prior Publication US 2019/0356924 A1, Nov. 21, 2019
Int. Cl. H04N 19/167 (2014.01); H04N 19/126 (2014.01); H04N 19/18 (2014.01); H04N 19/46 (2014.01)
CPC H04N 19/167 (2014.11) [H04N 19/126 (2014.11); H04N 19/18 (2014.11); H04N 19/46 (2014.11)] 4 Claims
OG exemplary drawing
 
1. A video decoding method comprising:
determining a scale factor for a current block depending on whether or not the current block is a transform skip block;
obtaining dequantized transform coefficients of the current block by performing dequantization on transform coefficients of the current block based on the scale factor;
determining a transform type of the current block, wherein the transform type of the current block is determined as one of an intra prediction mode-independent DCT (Discrete Cosine Transform) and an intra prediction mode-independent DST (Discrete Sine Transform); and
obtaining residual samples of the current block by performing the transform on the dequantized transform coefficients based on the determined transform type,
wherein the transform type of the current block is determined for a vertical direction and a horizontal direction, respectively,
wherein when the current block is not intra-predicted, both the transform type of the horizontal direction and the transform type of the vertical direction of the current block are determined as DCT,
wherein when the current block is intra-predicted, the transform type of the current block is determined based on a block size of the current block,
wherein when the current block is intra-predicted and the size of the current block is 4×4, both the transform type of the horizontal direction and the transform type of the vertical direction of the current block are determined as DST independently from the intra prediction mode of the current block,
wherein when the current block is intra-predicted and the size of the current block is not 4×4, both the transform type of the horizontal direction and the transform type of the vertical direction of the current block are determined as DCT,
wherein determining the transform type of the current block is skipped when the current block is a transform skip block,
wherein, when the current block is not the transform skip block, the scale factor for the current block is determined based on a quantization matrix defined at the decoding apparatus and a location of a transform coefficient within the current block, and when the current block is the transform skip block, the scale factor for the current block is derived equal to a fixed constant value, regardless of the location of the transform coefficient within the current block, and
wherein the scale factor comprises an integer greater than or equal to 16.