Method and apparatus for encoding/decoding image

Patent metadata

Field	Value
Publication number	US-11297309-B2
Application number	US-201917040765-A
Country	US
Kind code	B2
Filing date	Apr 1, 2019
Priority date	Apr 1, 2018
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

The objective of the present invention is to provide a method and an apparatus for intra-prediction. In addition, the objective of the present invention is to provide a method and an apparatus for intra-prediction on a subblock unit basis. Furthermore, the objective of the present invention is to provide a method and an apparatus for determining a division and an encoding order of subblock units.

First claim

The invention claimed is:

1. An intra-prediction method performed by an image decoding apparatus, the method comprising:
dividing, based on partitioning information of a coding block, the coding block into a plurality of sub-blocks, the partitioning information including at least one of first partitioning information indicating whether to divide into four sub-blocks, second partitioning information indicating whether to divide into two sub-blocks or third partitioning information indicating a partitioning direction;
determining a coding order of the sub-blocks based on the partitioning information and a size of the coding block; and
generating a prediction block of each sub-block based on the coding order of the sub-blocks and an intra-prediction mode of the each sub-block.

2. The method of claim 1 , wherein the coding order is determined based on whether the coding block is divided in a vertical direction or a horizontal direction according to the third partitioning information.

3. The method of claim 2 , wherein the coding order is determined by further considering whether or not a shape of the coding block is a non-square with a width greater than a height.

4. The method of claim 1 , wherein determining the coding order of the coding block comprises obtaining, from a bitstream, selection information for determining the coding order of the coding block among pre-defined coding order candidates, and
wherein the coding order is determined by further considering the obtained selection information.

5. The method of claim 4 , wherein the pre-defined coding order candidates include a horizontal scan and an inverse-horizontal scan.

6. The method of claim 5 , wherein the prediction block is generated by using a neighboring block of a current block,
wherein the current block is representative of one of the sub-blocks, and
wherein the neighboring block includes at least one of a left neighboring block, a top neighboring block, a top-left neighboring block, a bottom-left neighboring block, or a top-right neighboring block.

7. The method of claim 6 , wherein the neighboring block further includes at least one of a right neighboring block or a bottom-right neighboring block.

8. The method of claim 7 , wherein a position of the neighboring block for intra prediction of the current block is variably determined based on the determined coding order.

9. An intra-prediction method performed by an image encoding apparatus, the method comprising:
determining partitioning information for dividing a coding block into a plurality of sub-blocks, the partitioning information including at least one of first partitioning information indicating whether to divide into four sub-blocks, second partitioning information indicating whether to divide into two sub-blocks or third partitioning information indicating a partitioning direction;
determining a coding order of the sub-blocks based on the partitioning information and a size of the coding block; and
generating a prediction block of each sub-block based on the coding order of the sub-blocks and an intra-prediction mode of the each sub-block.

10. A non-transitory computer readable medium having stored thereon instructions that when executed by a processor perform a method, comprising:
dividing, based on partitioning information of a coding block, the coding block into a plurality of sub-blocks, the partitioning information including at least one of first partitioning information indicating whether to divide into four sub-blocks, second partitioning information indicating whether to divide into two sub-blocks or third partitioning information indicating a partitioning direction;
determining a coding order of the sub-blocks based on the partitioning information and a size of the coding block; and
generating a prediction block of each sub-block based on the coding order of the sub-blocks and an intra-prediction mode of the each sub-block.

11. A non-transitory computer readable recording medium storing a bitstream that is generated by an intra-prediction method performed by an image encoding apparatus, the intra-prediction method comprising:
determining partitioning information for dividing a coding block into a plurality of sub-blocks, the partitioning information including at least one of first partitioning information indicating whether to divide into four sub-blocks, second partitioning information indicating whether to divide into two sub-blocks or third partitioning information indicating a partitioning direction;
determining a coding order of the sub-blocks based on the partitioning information and a size of the coding block; and
generating a prediction block of each sub-block based on the coding order of the sub-blocks and an intra-prediction mode of the each sub-block.

Assignees

• B1 Institute Image Technology Inc

Inventors

• Kim Ki Baek

Classifications

• H04N19/61

  in combination with predictive coding · CPC title

• H04N19/593 Primary

  involving spatial prediction techniques · CPC title

• H04N19/157

  Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter · CPC title

• H04N19/129

  Scanning of coding units, e.g. zig-zag scan of transform coefficients or flexible macroblock ordering [FMO] · CPC title

• H04N19/119 Primary

  Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks · CPC title