Intra-prediction with multiple refence lines

Patent metadata

Field	Value
Publication number	US-12425580-B2
Application number	US-202318468956-A
Country	US
Kind code	B2
Filing date	Sep 18, 2023
Priority date	May 9, 2017
Publication date	Sep 23, 2025
Grant date	Sep 23, 2025

Abstract

An encoding or decoding method implemented by a video coding device is provided. In an encoding method, the video coding device determines a value of a reference line index of a coding unit, and determines an intra-prediction mode from a list of most probable modes when the value of the reference line index indicates an additional reference line. The video coding device also encodes coding unit into a bitstream based on the intra-prediction mode, and stores the bitstream in a memory of the video coding device. In example decoding method, the video coding device receives a bitstream, determines a value of a reference line index of a coding unit, and determines an intra-prediction mode from a list of most probable modes when a value of the reference line index indicates an additional reference line. The video coding device also decodes the coding unit based on the intra-prediction mode.

First claim

What is claimed is:

1. A method implemented by a video coding device, comprising:
receiving a bitstream, wherein the bitstream includes information for a coding unit;
determining a value of a reference line index of the coding unit;
determining an intra-prediction mode from a list of most probable modes when a value of the reference line index indicates an additional reference line; and
decoding the coding unit based on the intra-prediction mode.

2. The method of claim 1 , further comprising determining the intra-prediction mode from a group of modes that excludes the list of most probable modes when the value of the reference line index indicates a primary reference line.

3. The method of claim 1 , wherein the list of most probable modes are signaled by a most probable mode index when the value of the reference line index indicates the additional reference line.

4. The method of claim 2 , wherein the group of modes that excludes the list of most probable modes are indexed by an intra-prediction mode index.

5. The method of claim 1 , wherein the list of most probable modes includes intra-prediction modes used by neighbor coding units.

6. The method of claim 1 , wherein the value of the reference line index is inferred to be equal to zero when not present.

7. A non-transitory computer-readable recording medium storing instructions that, when executed by one or more processors, cause a coding device to:
encode a value of a reference line index of a coding unit; and
encode an intra-prediction mode determined from a list of most probable modes when the value of the reference line index indicates an additional reference line.

8. The non-transitory computer-readable recording medium of claim 7 , wherein the intra-prediction mode is determined from a group of modes that excludes the list of most probable modes when the value of the reference line index indicates a primary reference line.

9. The non-transitory computer-readable recording medium of claim 7 , wherein the list of most probable modes are signaled by a most probable mode index when the value of the reference line index indicates the additional reference line.

10. The non-transitory computer-readable recording medium of claim 8 , wherein the group of modes that excludes the list of most probable modes are indexed by an intra-prediction mode index.

11. The non-transitory computer-readable recording medium of claim 7 , wherein the list of most probable modes includes intra-prediction modes used by neighbor coding units.

12. The non-transitory computer-readable recording medium of claim 7 , wherein the value of the reference line index is inferred to be equal to zero when not present.

13. The non-transitory computer-readable storage medium of claim 7 , wherein one or more of the value of the reference line index of the coding unit and the intra-prediction mode determined from the list of most probable modes is encoded into a bitstream, and wherein the instructions include the bitstream.

14. A method implemented by a video coding device, comprising:
determining a value of a reference line index of a coding unit;
determining an intra-prediction mode from a list of most probable modes when the value of the reference line index indicates an additional reference line;
encoding the coding unit into a bitstream based on the intra-prediction mode; and
storing the bitstream in a memory of the video coding device.

15. The method of claim 14 , further comprising determining the intra-prediction mode from a group of modes that excludes the list of most probable modes when the value of the reference line index indicates a primary reference line.

16. The method of claim 14 , wherein the list of most probable modes are signaled by a most probable mode index when the value of the reference line index indicates the additional reference line.

17. The method of claim 15 , wherein the group of modes that excludes the list of most probable modes are indexed by an intra-prediction mode index.

18. The method of claim 14 , wherein the list of most probable modes includes intra-prediction modes used by neighbor coding units.

19. The method of claim 14 , wherein the value of the reference line index is omitted from the bitstream when the value of the reference line index is equal to zero.

Assignees

• Futurewei Technologies Inc

Inventors

• Liu Shan
• Ma Xiang

Classifications

• H04N19/523

  with sub-pixel accuracy · CPC title

• H04N19/61

  in combination with predictive coding · CPC title

• H04N19/107

  between spatial and temporal predictive coding, e.g. picture refresh · 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