US 11,689,728 B2
Intra prediction mode encoding/decoding method and apparatus
Jin Ho Lee, Daejeon (KR); Hui Yong Kim, Daejeon (KR); Sung Chang Lim, Daejeon (KR); Jin Soo Choi, Daejeon (KR); Jin woong Kim, Daejeon (KR); Jae Gon Kim, Goyang-si (KR); Hae Chul Choi, Daejeon (KR); and Sang Yong Lee, Goyang-si (KR)
Assigned to DOLBY LABORATORIES LICENSING CORPORATION, San Francisco, CA (US)
Filed by ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE, Daejeon (KR); and INTELLECTUAL DISCOVERY CO., LTD., Seoul (KR)
Filed on Oct. 18, 2021, as Appl. No. 17/503,570.
Application 17/503,570 is a continuation of application No. 16/850,342, filed on Apr. 16, 2020, granted, now 11,172,206.
Application 16/850,342 is a continuation of application No. 15/913,099, filed on Mar. 6, 2018, granted, now 10,666,950, issued on May 26, 2020.
Application 15/913,099 is a continuation of application No. 14/365,663, granted, now 9,955,169, issued on Apr. 24, 2018, previously published as PCT/KR2013/000770, filed on Jan. 30, 2013.
Claims priority of application No. 10-2012-0009222 (KR), filed on Jan. 30, 2012; and application No. 10-2013-0010488 (KR), filed on Jan. 30, 2013.
Prior Publication US 2022/0038712 A1, Feb. 3, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/157 (2014.01); H04N 19/11 (2014.01); H04N 19/176 (2014.01); H04N 19/196 (2014.01); H04N 19/593 (2014.01); H04N 19/70 (2014.01)
CPC H04N 19/157 (2014.11) [H04N 19/11 (2014.11); H04N 19/176 (2014.11); H04N 19/198 (2014.11); H04N 19/593 (2014.11); H04N 19/70 (2014.11)] 3 Claims
OG exemplary drawing
 
1. An image decoding method, with a decoding apparatus, the method comprising:
generating, with the decoding apparatus, an MPM list comprising a plurality of MPMs (Most Probable Modes) for a current prediction unit,
wherein the MPMs are derived based on intra prediction modes of neighboring prediction units to the current prediction unit, and the neighboring prediction units comprise a left neighboring prediction unit and an upper neighboring prediction unit,
wherein the MPM list comprises three MPMs as candidate intra prediction modes of the current prediction unit, the three MPMs comprising a first MPM, a second MPM and a third MPM, and
wherein when the intra prediction modes of the neighboring prediction units are the same, the first MPM is set equal to the intra prediction modes of the neighboring prediction units while the second MPM is set different to the intra prediction modes of the neighboring prediction units;
deriving, with the decoding apparatus, an intra prediction mode of the current prediction unit based on the MPM list and an MPM flag indicating whether there is, among the derived MPMs, an MPM having the same prediction mode as the intra prediction mode of the current prediction unit;
generating, with the decoding apparatus, a prediction block of the current prediction unit by performing intra prediction on the current prediction unit based on the intra prediction mode of the current prediction unit; and
obtaining, with the decoding apparatus, a residual block of the current prediction unit;
generating, with the decoding apparatus, a restored block of the current prediction unit using the prediction block of the current prediction unit and the residual block of the current prediction unit,
wherein in response to the MPM flag indicating that there is, among the derived three MPMs, no MPM having the same prediction mode as the intra prediction mode of the current prediction unit, deriving the intra prediction mode of the current prediction unit comprises:
comparing, with the decoding apparatus, the three MPMs in the MPM list,
rearranging, with the decoding apparatus, the three MPMs based on results of the comparison, the rearranging being performed by changing positions of the three MPMs in an ascending order of mode values, the step of rearranging is performed only if the MPM flag indicates that there is, among the derived three MPMs, no MPM which has the same intra prediction mode of the current prediction unit;
setting, with the decoding apparatus, a remaining intra prediction mode as a candidate intra prediction mode of the current prediction unit, the remaining intra prediction mode being determined based on remaining intra prediction modes except the derived three MPMs among all intra prediction modes;
increasing, with the decoding apparatus, a value of the candidate intra prediction mode by 1 when the value of the candidate intra prediction mode is equal to or greater than the value of a first rearranged MPM;
increasing, with the decoding apparatus, the value of the candidate intra prediction mode by 1 when the value of the candidate intra prediction mode is equal to or greater than the value of a second rearranged MPM;
increasing, with the decoding apparatus, the value of the candidate intra prediction mode by 1 when the value of the candidate intra prediction mode is equal to or greater than the value of a third rearranged MPM; and
deriving, with the decoding apparatus, the intra prediction mode of the current prediction unit based on an intra prediction mode corresponding to the value of the candidate intra prediction mode.