Method and apparatus of non-square intra prediction for chroma components in coding system with quad-tree and binary-tree partition

Patent metadata

Field	Value
Publication number	US-10944989-B2
Application number	US-201615561110-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Apr 1, 2015
Publication date	Mar 9, 2021
Grant date	Mar 9, 2021

Abstract

A method and apparatus for Intra prediction of non-square chroma blocks are disclosed. The system uses a block partitioning structure for partitioning a chroma block into one or more final sub-blocks including at least one non-square final sub-block using block partition recursively. The block partition either splits each given block into intermediate sub-blocks using one or more split modes including one binary split mode or applies no splitting to each given block. The block is treated as an initial given block and each intermediate sub-block is treated as one given block in a next recursion. Any given block that is not further split becomes a final sub-block. After the final sub-blocks are determined, non-square Intra prediction is applied to each non-square final sub-block.

First claim

The invention claimed is:

1. A method of video decoding using Intra prediction for video data comprising:
receiving a video bitstream including coded data for a current block;
deriving, from the video bitstream, a block partitioning structure for partitioning the current block into one or more final sub-blocks including at least one non-square final sub-block using block partition recursively, wherein the block partition either splits each given block into intermediate sub-blocks using one or more split modes including one binary split mode or applies no splitting to each given block, the current block is treated as an initial given block, each intermediate sub-block is treated as one given block in a next recursion, and any one given block not further split becomes one final sub-block; and
reconstructing each non-square final sub-block using non-square Intra prediction by including X additional neighboring reconstructed samples or excluding X neighboring reconstructed samples for deriving DC predictor associated with DC Intra predictor mode, and/or including Y additional neighboring reconstructed samples or excluding Y neighboring reconstructed samples for deriving Intra prediction parameters associated with LM (luma-predict-chroma) Intra prediction mode, wherein X and Y are positive integers,
wherein each non-square final sub-block has neighboring reconstructed samples along a short side and a long side of each non-square final sub-block, wherein at least one of a first length of the long side of each non-square final sub-block and a second length of the short side of each non-square final sub-block is a power-of-2 integer, wherein X or Y equals the first length of the long side of each non-square final sub-block minus the second length of the short side of each non-square final sub-block, wherein said reconstructing each non-square final sub-block using non-square Intra prediction comprises deriving DC predictor associated with DC Intra predictor mode based only on neighboring reconstructed samples of the long side of each non-square final sub-block, and wherein the DC predictor is a value that is an average of the neighboring reconstructed samples of the long side.

2. The method of claim 1 , wherein the block partition corresponds to combined quad and binary partition that splits each given block into intermediate sub-blocks using quad split, horizontal binary split or vertical binary split, or applies no split to each given block.

3. The method of claim 1 , wherein the current block corresponds to one coding tree unit (CTU) and said one or more final sub-blocks correspond to one or more coding units (CUs) wherein pixels in each CU share common coding information.

4. The method of claim 1 , wherein the current block corresponds to one coding unit (CU) and said one or more final sub-blocks correspond to one or more prediction units (PUs) wherein pixels in each CU share common coding information and pixels in each PU share common prediction information.

5. The method of claim 4 , wherein if a non-square PU corresponds to a 2N×N or N×2N block, the non-square PU is partitioned into N×N transform units (TUs), wherein transform processing is applied to each transform unit (TU).

6. The method of claim 4 , wherein each coding unit (CU) is also partitioned into one or more transform units (TUs) according to a same block partition tree as said one or more prediction units (PUs), and wherein transform process is applied to each transform unit.

7. The method of claim 1 , wherein the X or Y additional neighboring reconstructed samples are from extended neighboring reconstructed samples in line with neighboring reconstructed samples on the short side of each non-square final sub-block.

8. The method of claim 1 , wherein the X or Y additional neighboring reconstructed samples are from a line of reconstructed samples adjacent to neighboring reconstructed samples on the short side of each non-square final sub-block.

9. The method of claim 1 , wherein the X or Y neighboring reconstructed samples to be excluded are from X-consecutive neighboring reconstructed samples on the long side of each non-square final sub-block.

10. The method of claim 1 , wherein the X or Y neighboring reconstructed samples to be excluded are selected in an interleaved manner from neighboring reconstructed samples on the long side of each non-square final sub-block.

11. The method of claim 1 , wherein said reconstructing each non-square final sub-block using non-square Intra prediction further comprises deriving Intra prediction parameters associated with LM Intra prediction mode based only on specific neighboring chroma reconstructed samples, wherein the specific neighboring chroma reconstructed samples are selected from neighboring reconstructed samples along the short side and the long side of each non-square final sub-block, and a number of the specific neighboring chroma reconstructed samples is power-of-2.

12. The method of claim 1 , wherein said reconstructing each non-square final sub-block using non-square Intra prediction comprises deriving DC predictor associated with DC Intra predictor mode or deriving Intra prediction parameters associated with LM Intra prediction mode based only on neighboring reconstructed samples of the short side of each non-square final sub-block, wherein the second length of the short side of each non-square final sub-block is a power-of-2 integer.

13. A method of video coding using Intra prediction video data, comprising:
receiving input data for a current block;
partitioning the current block into one or more final sub-blocks including at least one non-square final sub-block using block partition recursively, wherein the block partition either splits each given block into intermediate sub-blocks using one or more split modes including one binary split mode or applies no splitting to each given block, the current block is treated as an initial given block, each intermediate sub-block is treated as one given block in a next recursion, and any one given block not further split becomes one final sub-block; and
applying non-square Intra prediction to each non-square final sub-block by including X additional neighboring reconstructed samples or excluding X neighboring reconstructed samples for deriving DC predictor associated with DC Intra predictor mode, and/or including Y additional neighboring reconstructed samples or excluding Y neighboring reconstructed samples for deriving Intra prediction parameters associated with LM (luma-predict-chroma) Intra prediction mode, wherein X and Y are positive integers,
wherein each non-square final sub-block has neighboring reconstructed samples along a short side and a long side of each non-square final sub-block, wherein at least one of a first length of the long side of each non-square final sub-block and a second length of the short side of each non-square final sub-block is a power-of-2 integer, wherein X or Y equals the first length of the long side of each non-square final sub-block minus the second length of the short side of each non-square final sub-block, wherein said applying non-square Intra prediction to each non-square final sub-block comprises deriving DC predictor associated with DC Intra predictor mode based only on neighboring reconstructed samples of the long side of each non-square final sub-block, and wherein the DC predictor is a value that is an average of the neighboring reconstructed samples of the long side.

14. The method of claim 13 , wherein the block partition corresponds to combined quad and binary partition that splits each given block into intermediate sub-blocks using quad split, horizo

Assignees

• Mediatek Inc

Inventors

• Chen Yi-Wen
• An Jicheng
• Lin Jian-Liang
• Huang Yu-Wen

Classifications

• H04N19/122

  Selection of transform size, e.g. 8x8 or 2x4x8 DCT; Selection of sub-band transforms of varying structure or type · CPC title

• H04N19/593 Primary

  involving spatial prediction techniques · CPC title

• H04N19/186

  the unit being a colour or a chrominance component · CPC title

• H04N19/96

  Tree coding, e.g. quad-tree coding · CPC title

• H04N19/176

  the region being a block, e.g. a macroblock · CPC title