Logical intra mode naming in HEVC video coding

Patent metadata

Field	Value
Publication number	US-10623772-B2
Application number	US-201816163269-A
Country	US
Kind code	B2
Filing date	Oct 17, 2018
Priority date	Jan 20, 2012
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

A method and apparatus of using logical mode numbers during both prediction and coding in the bit stream, such as for high efficiency video coders (HEVC). These logical intra mode numbers are sorted based on angle which as a result leads to improved coding designs with fewer and smaller look-up tables, and a small gain in coding efficiency. Furthermore, by using this type of naming, the number of most probable modes (MPMs) can be readily extended since no additional tables are required. The use of three MPMs achieves a larger gain of 0.25% and 0.31% for the AI_HE and AI_LC cases, respectively.

First claim

What is claimed is:

1. An image processing apparatus, comprising:
a memory configured to store instructions; and
a processor configured to execute the instructions stored in the memory, wherein the processor is further configured to:
set candidate intra prediction modes based on a determination that (A) a first intra prediction mode for a left neighboring block adjacent to a current block is unequal to a second intra prediction mode for an above neighboring block adjacent to the current block, and (B) both the first intra prediction mode and the second intra prediction mode are not planar prediction; and
perform intra prediction based on a third intra prediction mode selected from the candidate intra prediction modes,
wherein the set of the candidate intra prediction modes comprises set a mode number that indicates the candidate intra prediction modes, and
wherein mode number 0 indicates the first intra prediction mode, mode number 1 indicates the second intra prediction mode, and mode number 2 indicates the planar prediction.

2. The image processing apparatus of claim 1 , wherein the processor is further configured to:
obtain the mode number from a bit stream; and
set the third intra prediction mode from the candidate intra prediction modes based on the mode number that is obtained from the bit stream.

3. The image processing apparatus of claim 1 , wherein the left neighboring block and the above neighboring block are Transform Units.

4. The image processing apparatus of claim 1 , wherein the left neighboring block and the above neighboring block are Prediction Units.

5. The image processing apparatus of claim 1 , wherein the candidate intra prediction modes are intra prediction modes from most probable modes (MPMs).

6. A method, comprising:
in an image processing apparatus:
setting candidate intra prediction modes based on a determination that (A) a first intra prediction mode for a left neighboring block adjacent to a current block is unequal to a second intra prediction mode for an above neighboring block adjacent to the current block, and (B) both the first intra prediction mode and the second intra prediction mode are not planar prediction; and
performing intra prediction based on a third intra prediction mode selected from the candidate intra prediction modes,
wherein the setting of the candidate intra prediction modes comprises set a mode number that indicates the candidate intra prediction modes, and
wherein mode number 0 indicates the first intra prediction mode, mode number 1 indicates the second intra prediction mode, and mode number 2 indicates the planar prediction.

7. The method of claim 6 , further comprising:
obtaining the mode number from a bit stream; and
setting the third intra prediction mode from the candidate intra prediction modes based on the mode number that is obtained from the bit stream.

8. The method of claim 6 , wherein the left neighboring block and the above neighboring block are Transform Units.

9. The method of claim 6 , wherein the left neighboring block and the above neighboring block are Prediction Units.

10. The method of claim 6 , wherein the candidate intra prediction modes are intra prediction modes from most probable modes (MPMs).

Assignees

• Sony Corp

Inventors

• Maani Ehsan
• Tabatabai Ali J
• Xu Jun

Classifications

• H04N19/593 Primary

  involving spatial prediction techniques · CPC title

• H04N19/70 Primary

  characterised by syntax aspects related to video coding, e.g. related to compression standards · CPC title

• H04N19/61 Primary

  in combination with predictive coding · CPC title

• H04N19/463

  by compressing encoding parameters before transmission · CPC title

• H04N19/176

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