Sample adaptive offset (SAO) in accordance with video coding

Patent metadata

Field	Value
Publication number	US-9282328-B2
Application number	US-201313758169-A
Country	US
Kind code	B2
Filing date	Feb 4, 2013
Priority date	Feb 10, 2012
Publication date	Mar 8, 2016
Grant date	Mar 8, 2016

Abstract

Sample adaptive offset (SAO) in accordance with video coding. SAO filtering may be performed before de-blocking processing (e.g., in accordance with video signal decoding and/or encoding). For example, a receiver and/or decoder communication device may receive signaling from a transmitter and/or encoder communication device that includes various band offsets. Corresponding band indices may be determined via analysis of the received video signal (e.g., received from the transmitter and/or encoder communication device), inferentially without requiring signaling of such band indices from the transmitter and/or encoder communication device. Upon appropriate analysis of one or more largest coding units (LCUs) generated from the video signal to determine a pixel value distribution (e.g., which may be using a histogram in one instance), then based on that pixel value distribution, the band indices are identified and the band offsets applied thereto.

First claim

What is claimed is:

1. An apparatus, A communication device comprising:
at least one input configured to receive:
a video signal from another communication device; and
a plurality of band offsets via signaling from the another communication device; and

a processor configured to:
analyze a plurality of pixels associated with at least one largest coding unit (LCU) associated with the video signal to identify a pixel value distribution;
identify a plurality of band indices inferentially based on the pixel value distribution;
apply the plurality of band offsets to the plurality of band indices when performing filter processing of the video signal;
perform sample adaptive offset (SAO) filter processing of the video signal to generate a first filtered signal, wherein the SAO filter processing including to apply a first band offset of the plurality of band offsets corresponding to a first band index of the plurality of band indices to a first set of pixels within a first band of the plurality of bands and to apply a second band offset of the plurality of band offsets corresponding to a second band index of the plurality of band indices to a second set of pixels within a second band of the plurality of bands; and
perform de-blocking filter processing of the first filtered signal that is generated by the SAO filter processing to generate a second filtered signal.

2. The communication device of claim 1 , wherein the processor is further configured to:
analyze the plurality of pixels associated with the at least one LCU associated with the video signal to generate a pixel value histogram that represents the pixel value distribution; and
based on the pixel value histogram, identify the plurality of band indices to which the plurality of band offsets are applied.

3. The communication device of claim 1 , wherein:
the plurality of band indices has a discontinuous distribution such that at least two successive of the plurality of band indices that are separated from one another by at least one band index value.

4. The communication device of claim 1 , wherein:
the pixel value distribution indicates a plurality of subsets of the plurality of pixels associated respectively with at least some of the plurality of band indices; and
the plurality of band indices, to which the plurality of band offsets is applied, corresponds to at least one of the plurality of subsets of the plurality of pixels having relatively larger or largest numbers of pixels in comparison other of the plurality of subsets of the plurality of pixels.

5. The communication device of claim 1 ,
wherein the a communication device is operative within at least one of a satellite communication system, a wireless communication system, a wired communication system, a fiber-optic communication system, or a mobile communication system.

6. A communication device comprising:
an input configured to receive a video signal and a plurality of band offsets from another communication device; and
a processor configured to:
analyze a plurality of pixels associated with at least one largest coding unit (LCU) associated with the video signal to identify a pixel value distribution and to classify the plurality of pixels, based on the pixel value distribution, into a plurality of bands based on the plurality of band indices;
apply the plurality of band offsets to the plurality of band indices when performing sample adaptive offset (SAO) filter processing of the video signal to generate a first filtered signal to generate a first filtered signal, wherein the performing SAO filter processing includes applying a first band offset of the plurality of band offsets corresponding to a first band index of the plurality of band indices to a first set of pixels within a first band of the plurality of bands and applying a second band offset of the plurality of band offsets corresponding to a second band index of the plurality of band indices to a second set of pixels within a second band of the plurality of bands; and
perform de-blocking filter processing of the first filtered signal that is generated by the SAO filter processing to generate a second filtered signal.

7. The communication device of claim 6 , wherein the processor is further configured to:
performing the SAO filter processing by applying a zero offset to at least one other set of pixels within at least one other band of the plurality of bands.

8. The communication device of claim 6 , wherein the processor is further configured to:
analyze the plurality of pixels associated with the at least one LCU associated with the video signal to generate a pixel value histogram that represents the pixel value distribution; and
based on the pixel value histogram, identify the plurality of band indices to which the plurality of band offsets are applied.

9. The communication device of claim 6 ,
wherein the plurality of band indices has a discontinuous distribution such that at least two successive of the plurality of band indices that are separated from one another by at least one band index value.

10. The communication device of claim 6 , wherein:
the pixel value distribution indicates a plurality of subsets of the plurality of pixels associated respectively with at least some of the plurality of band indices; and
the plurality of band indices, to which the plurality of band offsets is applied, corresponds to at least one of the plurality of subsets of the plurality of pixels having relatively larger or largest numbers of pixels in comparison other of the plurality of subsets of the plurality of pixels.

11. The communication device of claim 6 , wherein:
the plurality of band offsets received by the communication device via signaling from the another communication device; and
the processor configured to identify the plurality of band indices inferentially based on the pixel value distribution.

12. The communication device of claim 6 , wherein:
the communication device is a receiver communication device that includes a video decoder;
the another communication device is a transmitter communication device that includes a video encoder; and
the receiver communication device and the transmitter communication device connected or communicatively coupled via at least one communication channel.

13. The apparatus communication device of claim 6 ,
wherein the communication device is operative within at least one of a satellite communication system, a wireless communication system, a wired communication system, a fiber-optic communication system, or a mobile communication system.

14. A method for execution by a communication device, the method comprising:
via an input of the communication device, receiving a video signal and a plurality of band offsets corresponding to a plurality of band indices from another communication device;
analyzing a plurality of pixels associated with at least one largest coding unit (LCU) associated with the video signal to identify a pixel value distribution and to classify the plurality of pixels, based on the pixel value distribution, into a plurality of bands based on the plurality of band indices;
applying the plurality of band offsets to the plurality of band indices when performing sample adaptive offset (SAO) filter processing of the video signal to generate a first filtered signal, wherein the performing SAO filter processing includes applying a first band offset of the plurality of band offsets corresponding to a first band index of the plurality of band indices to a first set of pixels within a first band of the plurality of bands and applying a second band offset of the plurality of band offse

Assignees

• Chen Peisong
• Wan Wade K
• Broadcom Corp

Inventors

• Chen Peisong
• Wan Wade K

Classifications

• H04N19/86

  involving reduction of coding artifacts, e.g. of blockiness · CPC title

• H04N19/82 Primary

  involving filtering within a prediction loop · CPC title

• H04N19/10 Primary

  using adaptive coding · CPC title

• H04N19/00006 Primary

  Electricity · mapped topic

• H04N7/24 Primary

  Systems for the transmission of television signals using pulse code modulation (H04N21/00 takes precedence) · CPC title