US 11,889,068 B2Granted

Intra prediction method and apparatus in image coding system

AssigneeLG Electronics Inc.

InventorsLing Li, Seunghwan Kim, Jin Heo

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Abstract

An image decoding method performed by a decoding apparatus according to the present disclosure comprises the steps of: obtaining a reference sample line index of a current block and most probable mode (MPM)-related information; constructing an alternative MPM list on the basis of the reference sample line index; deriving an intra prediction mode of the current block on the basis of the alternative MPM list and the MPM-related information; and generating a predicted block of the current block on the basis of the intra prediction mode, wherein the alternative MPM list is constructed on the basis of an intra prediction mode of an upper adjacent block of the current block and an intra prediction mode of a left adjacent block of the current block.

Claims7

Dependent claims

An image decoding method performed by a decoding apparatus, the method comprising:

obtaining image information including prediction related information, information on a reference sample line index and most probable mode (MPM) related information of a current block through a bitstream;
determining that an intra prediction is applied for the current block based on the prediction related information;
configuring an MPM list for the current block;
deriving an intra prediction mode of the current block based on the MPM list and the MPM related information;
deriving reference neighboring samples based on the information on the reference sample line index;
generating a predicted block for the current block based on the intra prediction mode and the reference neighboring samples;
and
generating a reconstructed picture based on the predicted block,
wherein the MPM list is configured based on a first intra prediction mode of a left neighboring block of the current block and a second intra prediction mode of a top neighboring block of the current block,
wherein the MPM list comprise a first MPM candidate, a second MPM candidate, a third MPM candidate, a fourth MPM candidate and a fifth MPM candidate,
wherein based on a case that a mode value of the first intra prediction mode is equal to a mode value of the second intra prediction mode and the mode value of the first intra prediction mode is greater than a mode value of a DC mode,
a mode value of the first MPM candidate is equal to the mode value of the first intra prediction mode,
a mode value of the second MPM candidate is equal to a result of an equation of (L+61)%64+2, L being the mode value of the first intra prediction mode,
a mode value of the third MPM candidate is equal to a result of an equation of (L−1)%64+2,
a mode value of the fourth MPM candidate is equal to a result of an equation of (L+60)%64+2, and
a mode value of the fifth MPM candidate is equal to a result of an equation of (L)%64+2.

13 more elements

An image encoding method performed by an encoding apparatus, the method comprising:

determining that an intra prediction is applied for a current block;
generating prediction related information;
deriving a reference sample line index of the current block;
generating information on the reference sample line index;
configuring a most probable mode (MPM) list for the current block;
deriving an intra prediction mode of the current block based on the MPM list;
generating MPM related information of the current block;
and
generating a bitstream by encoding image information including the prediction related information, the information on the reference sample line index and the MPM related information,
wherein the MPM list is configured based on a first intra prediction mode of a left neighboring block of the current block and a second intra prediction mode of a top neighboring block of the current block,
wherein the MPM list comprise a first MPM candidate, a second MPM candidate, a third MPM candidate, a fourth MPM candidate and a fifth MPM candidate,
wherein based on a case that a mode value of the first intra prediction mode is equal to a mode value of the second intra prediction mode and the mode value of the first intra prediction mode is greater than a mode value of a DC mode,
a mode value of the first MPM candidate is equal to the mode value of the first intra prediction mode,
a mode value of the second MPM candidate is equal to a result of an equation of (L+61)%64+2, L being the mode value of the first intra prediction mode,
a mode value of the third MPM candidate is equal to a result of an equation of (L−1)%64+2,
a mode value of the fourth MPM candidate is equal to a result of an equation of (L+60)%64+2, and
a mode value of the fifth MPM candidate is equal to a result of an equation of (L)%64+2.

14 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/964,368Filed 12 Oct 2022 · continuation
Priority: 4 Nov 2018
Published: US 2023/0039654 A19 Feb 2023
Granted: 30 Jan 2024
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H04N 19/11
Selection of coding mode or of prediction mode: among a plurality of spatial predictive coding modes
H04N 19/105
Selection of coding mode or of prediction mode: selection of the reference unit for prediction within a chosen coding or prediction mode, e.g.…
H04N 19/159
Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter:…
H04N 19/176
The unit being an image region, e.g. an object: the region being a block, e.g. a macroblock

Family

Application62/755,554Us provisional application · filed 4 Nov 2018
PCT/KR2019/011302Parent of this continuation · filed 3 Sep 2019
US 2023/0039654 A1Pre-grant publication · published 9 Feb 2023
Application17/279,459Parent of this continuation
US 11,509,891 B2Related patent
US 2022/0038691 A1Published application
US 11,889,068 B2This patent

From the US filing history. Foreign family members aren’t listed.