US 11,785,218 B2
Image decoding apparatus
Shin Ji Park, Seoul (KR)
Assigned to GENSQUARE LLC, Seoul (KR)
Filed by GENSQUARE LLC, Seoul (KR)
Filed on Feb. 4, 2020, as Appl. No. 16/781,624.
Application 16/781,624 is a continuation of application No. 15/053,801, filed on Feb. 25, 2016, granted, now 10,587,877.
Application 15/053,801 is a continuation of application No. 14/124,576, granted, now 9,288,488, issued on Mar. 15, 2016, previously published as PCT/KR2012/003085, filed on Apr. 20, 2012.
Claims priority of application No. 10-2011-0108456 (KR), filed on Oct. 24, 2011; and application No. 10-2011-0108460 (KR), filed on Oct. 24, 2011.
Prior Publication US 2020/0177881 A1, Jun. 4, 2020
Int. Cl. H04N 19/126 (2014.01); H04N 19/176 (2014.01); H04N 19/157 (2014.01); H04N 19/196 (2014.01); H04N 19/11 (2014.01); H04N 19/463 (2014.01); H04N 19/124 (2014.01); H04N 19/44 (2014.01); H04N 19/159 (2014.01); H04N 19/60 (2014.01); H04N 19/593 (2014.01)
CPC H04N 19/126 (2014.11) [H04N 19/11 (2014.11); H04N 19/124 (2014.11); H04N 19/157 (2014.11); H04N 19/159 (2014.11); H04N 19/176 (2014.11); H04N 19/196 (2014.11); H04N 19/45 (2014.11); H04N 19/463 (2014.11); H04N 19/198 (2014.11); H04N 19/44 (2014.11); H04N 19/593 (2014.11); H04N 19/60 (2014.11)] 7 Claims
OG exemplary drawing
 
1. An image encoding method comprising:
determining an intra prediction mode of a current prediction unit;
constructing a mode group including three intra prediction modes using valid intra prediction modes of left and top blocks of the current prediction unit;
determining a mode group indicator and a prediction mode index of the current prediction unit; and
encoding the mode group indicator and the prediction mode index,
wherein the mode group indicator indicates whether or not the intra prediction mode of the current prediction unit belongs to the mode group,
when the mode group indicator indicates that the intra prediction mode of the current prediction unit belongs to the mode group, the prediction mode index specifies the intra prediction mode of the current prediction unit in the mode group,
when the mode group indicator indicates that the intra prediction mode of the current prediction unit does not belong to the mode group, the prediction mode index specifies the intra prediction mode of the current prediction unit among intra prediction modes besides the three intra prediction modes in the mode group,
wherein a method of encoding the prediction mode index varies depending on the mode group indicator, and
wherein when only one of the intra prediction modes of the left and top blocks of the current prediction unit is valid, two intra prediction modes are added to the mode group.