Flexible band offset mode in sample adaptive offset in HEVC

Patent metadata

Field	Value
Publication number	US-11044488-B2
Application number	US-202016842257-A
Country	US
Kind code	B2
Filing date	Apr 7, 2020
Priority date	Jan 20, 2012
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

A Flexible Band Offset (FBO) apparatus and method of performing Sample Adaptive Offset (SAO) filtering within encoders and decoders, such as according to the High Efficiency Video Coding (HEVC) standard, and similarly configured coding devices. The number of Band Offset (BO) modes and the number of necessary offsets is reduced. The invention beneficially provides simpler coding, reduces temporary buffer size requirements, and can yield a small performance gain over existing SAO techniques of HEVC test model HM 5.

First claim

What is claimed is:

1. An encoding device, comprising:
circuitry configured to:
generate, in a band offset mode in which an offset is applied to each band that indicates a range to which pixel values belong, a modulo remainder for a number of a first band of consecutive bands based on a total number of bands;
set the first band and bands other than the first band included in the consecutive bands based on the modulo remainder, wherein
the first band is at a beginning of the consecutive bands;

apply the offset to each band of the set consecutive bands, wherein the consecutive bands are a plurality of divided bands of the total number of bands; and
encode an image to generate a bit stream comprising the offset.

2. The encoding device according to claim 1 , wherein the circuitry is further configured to:
select a position of the first band from 32 bands; and
determine 4 consecutive bands as the consecutive bands based on the selected position of the first band.

3. The encoding device according to claim 2 , wherein
the circuitry is further configured to set the bands other than the first band from the consecutive bands based on the modulo remainder, and
the modulo remainder is based on (the number of the first band+i)%32, and 0≤i≤3.

4. The encoding device according to claim 1 , wherein the circuitry is further configured to:
apply the offset to pixels that belongs to the consecutive bands for a decoded image; and
encode the image based on the decoded image.

5. The encoding device according to claim 4 , the circuitry is further configured to:
apply a deblocking filter on the decoded image; and
apply the offset to the pixels that belongs to the consecutive bands for the decoded image on which the deblocking filter is applied.

6. The encoding device according to claim 5 , wherein the circuitry is further configured to:
divide coding units by quadtree segmentation; and
encode the image for each coding unit.

7. The encoding device according to claim 6 , wherein the circuitry is further configured to divide the coding units into a prediction unit and a transformation unit.

8. An encoding method, comprising:
generating, in a band offset mode in which an offset is applied to each band that indicates a range to which pixel values belong, a modulo remainder for a number of a first band of consecutive bands based on a total number of bands;
setting the first band and bands other than the first band included in the consecutive bands based on the modulo remainder, wherein
the first band is at a beginning of the consecutive bands;

applying the offset to each band of the set consecutive bands, wherein the consecutive bands are a plurality of divided bands of the total number of bands; and
encoding an image to generate a bit stream comprising the offset.

9. The method according to claim 8 , further comprising:
selecting a position of the first band from 32 bands; and
determining 4 consecutive bands as the consecutive bands based on the selected position of the first band.

10. The method according to claim 9 , further comprising
setting the bands other than the first band from the consecutive bands based on the modulo remainder, wherein
the modulo remainder is based on (the number of the first band+i)%32, and 0≤i≤3.

11. The method according to claim 8 , further comprising:
applying the offset to pixels that belongs to the consecutive bands for a decoded image; and
encoding the image based on the decoded image.

12. The method according to claim 11 , further comprising:
applying a deblocking filter on the decoded image; and
applying the offset to the pixels that belongs to the consecutive bands for the decoded image on which the deblocking filter is applied.

13. The method according to claim 12 , further comprising:
dividing coding units by quadtree segmentation; and
encoding the image for each coding unit.

14. The method according to claim 13 , further comprising
dividing the coding units into a prediction unit and a transformation unit.

Assignees

• Sony Corp

Inventors

• Maani Ehsan
• Tabatabai Ali J
• Xu Jun

Classifications

• H04N19/117 Primary

  Filters, e.g. for pre-processing or post-processing (sub-band filter banks H04N19/635) · CPC title

• H04N19/00 Primary

  Methods or arrangements for coding, decoding, compressing or decompressing digital video signals · CPC title

• H04N19/50

  using predictive coding (H04N19/61 takes precedence) · CPC title

• H04N19/61

  in combination with predictive coding · CPC title

• H04N19/176 Primary

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