Method and apparatus for video encoding and decoding based on adaptive coefficient group

Patent metadata

Field	Value
Publication number	US-12363322-B2
Application number	US-202217971886-A
Country	US
Kind code	B2
Filing date	Oct 24, 2022
Priority date	Jun 29, 2018
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

Various implementations for video encoding and decoding are presented involving determining, for a block being encoded or decoded in a picture, a coefficient group mode for coding at least one coefficient of a set of transform coefficients of the image block; encoding or decoding the set of transform coefficients of the image block responsive to the coefficient group mode. The coefficient group mode can be determined from at least one of image block size, number of non-zero transform coefficients inside the image block, position of a transform coefficient inside the image block, decoded syntax element, wherein the coefficient group mode can specify whether a coefficient group significance flag is coded/decoded, indicating that at least one coefficient is non-zero inside a coefficient group and/or specify at least one size of the coefficient group.

First claim

The invention claimed is:

1. A method for video decoding, the method comprising:
obtaining a coding block, wherein the coding block comprises a first adaptive coefficient group associated with a first set of transform coefficients for the coding block and a second adaptive coefficient group associated with a second set of transform coefficients for the coding block;
determining a first position for the first adaptive coefficient group located in the coding block and determining a second position for the second adaptive coefficient group located in the coding block, wherein the first position for the first adaptive coefficient group is determined based on a first frequency domain and the second position for the second adaptive coefficient group is determined based on a second frequency domain;
based on the determined first position for the first adaptive coefficient group, obtaining a first adaptive coefficient group size for the first adaptive coefficient group, wherein the first adaptive coefficient group size is obtained based on the first frequency domain;
based on the determined second position for the second adaptive coefficient group, obtaining a second adaptive coefficient group size for the second adaptive coefficient group, wherein the second adaptive coefficient group size is obtained based on the second frequency domain, wherein the first frequency domain differs from the second frequency domain, and wherein the first adaptive coefficient group size differs from the second adaptive coefficient group size; and
decoding the coding block based on the obtained first adaptive coefficient group size and the obtained second adaptive coefficient group size.

2. The method of claim 1 , wherein the first frequency domain is a high frequency domain and the second frequency domain is a low frequency domain, wherein the first adaptive coefficient group size is larger than the second adaptive coefficient group size, and wherein the second adaptive coefficient group size is greater than or equal to 4×4.

3. The method of claim 1 , wherein the first position is located in the top left portion of the coding block and the second position is located in the bottom right portion of the coding block.

4. The method of claim 1 , wherein the coding block comprises a third adaptive coefficient group associated with a third set of transform coefficients for the coding block, and wherein the method comprises:
obtaining a third adaptive coefficient group size for the third adaptive coefficient group based on a third position for the third adaptive coefficient group, wherein the third position is located between the first position and the second position; and
decoding the coding block based on the obtained first adaptive coefficient group size, the obtained second adaptive coefficient group size, and the obtained third adaptive coefficient group size.

5. The method of claim 1 , wherein the first frequency domain is a low frequency domain and the second frequency domain is a high frequency domain, wherein the second adaptive coefficient group size is larger than the first adaptive coefficient group size, and wherein the first adaptive coefficient group size is greater than or equal to 4×4.

6. A device for video decoding, the device comprising:
a processor configured to:
obtain a coding block, wherein the coding block comprises a first adaptive coefficient group associated with a first set of transform coefficients for the coding block and a second adaptive coefficient group associated with a second set of transform coefficients for the coding block;
determine a first position for the first adaptive coefficient group located in the coding block and determining a second position for the second adaptive coefficient group located in the coding block, wherein the first position for the first adaptive coefficient group is determined based on a first frequency domain and the second position for the second adaptive coefficient group is determined based on a second frequency domain;
based on the determined first position for the first adaptive coefficient group, obtain a first adaptive coefficient group size for the first adaptive coefficient group, wherein the first adaptive coefficient group size is obtained based on the first frequency domain;
based on the determined second position for the second adaptive coefficient group, obtain a second adaptive coefficient group size for the second adaptive coefficient group, wherein the second adaptive coefficient group size is obtained based on the second frequency domain, wherein the first frequency domain differs from the second frequency domain, and wherein the first adaptive coefficient group size differs from the second adaptive coefficient group size; and
decode the coding block based on the obtained first adaptive coefficient group size and the obtained second adaptive coefficient group size.

7. The device of claim 6 , wherein the first frequency domain is a high frequency domain and the second position frequency domain is a low frequency domain, wherein the first adaptive coefficient group size is larger than the second adaptive coefficient group size, and wherein the second adaptive coefficient group size is greater than or equal to 4×4.

8. The device of claim 6 , wherein the first position is located in the top left portion of the coding block and the second position is located in the bottom right portion of the coding block.

9. The device of claim 6 , wherein the coding block comprises a third adaptive coefficient group associated with a third set of transform coefficients for the coding block, and wherein the processor is configured to:
obtain a third adaptive coefficient group size for the third adaptive coefficient group based on a third position for the third adaptive coefficient group, wherein the third position is located between the first position and the second position; and
decode the coding block based on the obtained first adaptive coefficient group size, the obtained second adaptive coefficient group size, and the obtained third adaptive coefficient group size.

10. The device of claim 6 , wherein the first frequency domain is a low frequency domain and the second frequency domain is a high frequency domain, wherein the second adaptive coefficient group size is larger than the first adaptive coefficient group size, and wherein the first adaptive coefficient group size is greater than or equal to 4×4.

11. A method for video encoding, the method comprising:
obtaining a coding block, wherein the coding block comprises a first adaptive coefficient group associated with a first set of transform coefficients for the coding block and a second adaptive coefficient group associated with a second set of transform coefficients for the coding block;
determining a first position for the first adaptive coefficient group located in the coding block and determining a second position for the second adaptive coefficient group located in the coding block, wherein the first position for the first adaptive coefficient group is determined based on a first frequency domain and the second position for the second adaptive coefficient group is determined based on a second frequency domain;
based on the determined first position for the first adaptive coefficient group, obtaining a first adaptive coefficient group size for the first adaptive coefficient group, wherein the first adaptive coefficient group size is obtained based on the first frequency domain;
based on the determined second position for the second adaptive coefficient group, obtaining a second adaptive coefficient group size for the second adaptive coefficient group, wherein the second adaptive coefficient group size i

Assignees

• Interdigital Vc Holdings Inc

Inventors

• Leleannec Fabrice
• Poirier Tangi
• Chen Ya

Classifications

• H04N19/70

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

• H04N19/176

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

• H04N19/147

  according to rate distortion criteria (rate-distortion as a criterion for motion estimation H04N19/567) · CPC title

• H04N19/14 Primary

  Coding unit complexity, e.g. amount of activity or edge presence estimation (H04N19/146 takes precedence) · CPC title

• H04N19/18 Primary

  the unit being a set of transform coefficients · CPC title