Digital video compression system, method and computer readable medium

Patent metadata

Field	Value
Publication number	US-9386304-B2
Application number	US-201313745378-A
Country	US
Kind code	B2
Filing date	Jan 18, 2013
Priority date	Nov 11, 2008
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

A video decoding method including: receiving an encoded block of data; decoding the encoded block of data to generate decoded data; and performing a sample adaptive offset on a whole or part of the decoded data, wherein a pixel B to be modified as part of the sample adaptive offset is adjacent to pixels A and C, and the pixel B is modified as part of the sample adaptive offset if (B≦A and B≦C) or (B≧A and B≧C).

First claim

The invention claimed is:

1. A video decoding method comprising:
receiving, at a decoding apparatus, an encoded block of data representing video frames transmitted from an encoding apparatus;
receiving, at the decoding apparatus from the encoding apparatus, a flag indicating that the encoded block of data has been encoded with a sample adaptive offset;
receiving, at the decoding apparatus from the encoding apparatus, one or more classification and offset parameters for the encoded block of data;
decoding, at the decoding apparatus, the encoded block of data to generate decoded data; and
performing, at the decoding apparatus, the sample adaptive offset on a whole or part of the decoded data according to the one or more classification and offset parameters,
wherein a pixel B to be modified as part of the sample adaptive offset is adjacent to pixels A and C, the pixel B is classified into one of five categories 1) B<A and B<C; 2) B<one neighbor and equal to the other; 3) B>one neighbor and equal to the other; 4) B>A and B>C; and 5) none of the above, and the categories 1) and 2) are combined in a first combined category for (B≦A and B≦C) and the categories 3) and 4) are combined in a second combined category for (B≧A and B≧C), and the pixel B is modified as part of the sample adaptive offset if (B≦A and B≦C) or (B≧A and B≧C).

2. The video decoding method of claim 1 , wherein if (B≦A and B≦C), then the modification to pixel B as part of the sample adaptive offset is ≧0, and if (B≧A and B≧C), then the modification to pixel B as part of the sample adaptive offset is ≦0.

3. The video decoding method of claim 1 , wherein if (B≦A and B≦C), then the modification to pixel B as part of the sample adaptive offset is 0 or 1, and if (B≧A and B≧C), then the modification to pixel B as part of the sample adaptive offset is 0 or −1.

4. The video decoding method of claim 1 , wherein if |A+C−2B|<2, then no modification is made to the pixel B as part of the sample adaptive offset.

5. The video decoding method of claim 1 , wherein if (B≦A and B≦C), then the modification to pixel B as part of the sample adaptive offset is only 1, and if (B≧A and B≧C), then the modification to pixel B as part of the sample adaptive offset is only −1.

6. The video decoding method of claim 5 , wherein if |A+C−2B|<2, then no modification is made to the pixel B as part of the sample adaptive offset.

7. The video decoding method of claim 1 ,
wherein the one or more classification and offset parameters include a signal indicating a value of modification applied to the pixel B.

8. The video decoding method of claim 1 ,
wherein the flag is a binary flag that indicates whether a simple mode sample adaptive offset is to be applied or if an advanced mode sample adaptive offset is to be applied.

9. The video decoding method of claim 1 ,
wherein the one or more classification and offset parameters include a signal that the pixel B is modified by a positive offset if pixel B belongs to a first category and or a negative offset if pixel B belongs to a second category.

10. The video decoding method of claim 1 , wherein an offset under consideration is Offset, wherein |Offset|>0, and pixel B is modified only if |A+C−B−B|≧2*|Offset|.

11. A non-transitory computer readable storage medium encoded with instructions, which when executed by a decoding apparatus causes the decoding apparatus to implement a video decoding method comprising:
receiving, at the decoding apparatus, an encoded block of data representing video frames transmitted from an encoding apparatus;
receiving, at the decoding apparatus from the encoding apparatus, a flag indicating that the encoded block of data has been encoded with a sample adaptive offset;
receiving, at the decoding apparatus from the encoding apparatus, one or more classification and offset parameters for the encoded block of data;
decoding, at the decoding apparatus, the encoded block of data to generate decoded data; and
performing, at the decoding apparatus, the sample adaptive offset on a whole or part of the decoded data according to the one or more classification and offset parameters,
wherein a pixel B to be modified as part of the sample adaptive offset is adjacent to pixels A and C, the pixel B is classified into one of five categories 1) B<A and B<C; 2) B<one neighbor and equal to the other; 3) B>one neighbor and equal to the other; 4) B>A and B>C; and 5) none of the above, and the categories 1) and 2) are combined in a first combined category for (B≦A and B≦C) and the categories 3) and 4) are combined in a second combined category for (B≧A and B≧C), and the pixel B is modified according to the first combined category or the second combined category.

12. The non-transitory computer readable storage medium of claim 11 , wherein if (B≦A and B≦C), then the modification to pixel B as part of the sample adaptive offset is ≧0, and if (B≧A and B≧C), then the modification to pixel B as part of the sample adaptive offset is ≦0.

13. The non-transitory computer readable storage medium of claim 11 , wherein if (B≦A and B≦C), then the modification to pixel B as part of the sample adaptive offset is 0 or 1, and if (B≧A and B≧C), then the modification to pixel B as part of the sample adaptive offset is 0 or −1.

14. The non-transitory computer readable storage medium of claim 11 , wherein if |A+C−2B|<2, then no modification is made to the pixel B as part of the sample adaptive offset.

15. The non-transitory computer readable storage medium of claim 11 , wherein if (B≦A and B≦C), then the modification to pixel B as part of the sample adaptive offset is only 1, and if (B≧A and B≧C), then the modification to pixel B as part of the sample adaptive offset is only −1.

16. The non-transitory computer readable storage medium of claim 15 , wherein if |A+C−2B|<2, then no modification is made to the pixel B as part of the sample adaptive offset.

17. The non-transitory computer readable storage medium of claim 11 , wherein
the one or more classification and offset parameters include a signal indicating a value of modification applied to the pixel B.

18. The non-transitory computer readable storage medium of claim 11 , wherein
the flag is a binary flag that indicates whether a simple mode sample adaptive offset is to be applied or if an advanced mode sample adaptive offset is to be applied.

19. The non-transitory computer readable storage medium of claim 11 , wherein
the one or more classification and offset parameters include a signal that the pixel B is modified by a positive offset if pixel B belongs to a first category and or a negative offset if pixel B belongs to a second category.

20. A decoding apparatus, comprising:
a memory that stores computer executable instructions;
a communication terminal that receives from an encoding apparatus an encoded block of data representing video frames, a flag indicating that the encoded block of data has been encoded with a sample adaptive offset, and one or more classification and offset parameters for the encoded block of data; and
a processor that executes the instructions in order to
decode the encoded block of data to generate decoded data, and
perform the sample adaptive offset on a whole or part of the decoded data according to the one or more classification and offset parameters,
wherein a pixel B to be modified as part of the sample adaptive offset is adjacent to pixels A and C, the pixel B is classified into one of five categories 1) B<A and B<C; 2) B<one neighbor and equal to the other

Assignees

• Cisco Tech Inc

Inventors

• Bjontegaard Gisle
• Fuldseth Arild

Classifications

• H04N19/00006 Primary

  Electricity · mapped topic

• H04N19/82 Primary

  involving filtering within a prediction loop · CPC title

• H04N19/10 Primary

  using adaptive coding · CPC title