Signaling for fading compensation

• US 7,609,767 B2
• Filed: 03/03/2003
• Issued: 10/27/2009
• Est. Priority Date: 05/03/2002
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Regunathan, Shankar, Srinivasan, Sridhar
• Primary Examiner(s): RAO, ANAND SHASHIKANT
• Application Number:
  US10/379,079
• Publication Number:
  US 20030206583A1
• Time in Patent Office: 2,430 Days
• Field of Search: 37524001-24029
• US Class Current: 375/240.25
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/517 by encoding
• CPC Class Codes: H04N 19/53 Multi-resolution motion estimation; Hierarchical motion estimation
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 19/85 using pre-processing or post-processing specially adapted for video compression
• CPC Class Codes: H04N 19/93 Run-length coding

Abstract

Techniques and tools for signaling for fading compensation in video processing applications are described. For example, a video encoder performs fading compensation on a reference image, signals that fading compensation is used, and signals fading parameters for the fading compensation. A video decoder receives the signaled information and performs fading compensation on the reference image according to the fading parameters.

Claims

1. A computer-implemented method for transforming encoded video information using a computing device that implements a video decoder, the computing device comprising a processing unit and memory, the method comprising, during video decoding:

with the computing device that implements the video decoder;

receiving and processing, at a video sequence level, a fading compensation capability signal for a video sequence;

if fading compensation is enabled, receiving and processing, at frame level, one or more fading compensation on/off signals for video frames in the video sequence, wherein fading parameters follow, at the frame level, the one or more fading compensation on/off signals; and

if fading compensation is enabled, performing fading compensation for at least part of a current video frame, comprising adjusting plural pixel values in a reference video frame based at least in part on the fading parameters.

2. The method of claim 1 wherein the one or more fading compensation on/off signals comprise one bit per video frame indicating whether or not fading compensation is used for that video frame.

3. The method of claim 1 wherein the one or more fading compensation on/off signals comprise one or more entropy codes per video frame, the one or more entropy codes jointly indicating whether or not fading compensation is used and other frame-level information.

4. A computer-readable medium storing computer-executable instructions for causing a computer system programmed thereby to perform the method of claim 1.

5. A computer-implemented method for transforming video information using a computing device that implements a video encoder, the computing device comprising a processing unit and memory, the method comprising, during video encoding:

with the computing device that implements the video encoder;

for each of plural video frames;

detecting global luminance change in the video frame;

if global luminance change is detected in the video frame, estimating global luminance change parameters for the video frame;

determining a value of a global luminance change compensation on/off signal for the video frame, wherein the value depends on whether global luminance change compensation is used for the video frame;

entropy coding the value for the global luminance change compensation on/off signal jointly with other frame-level information for the video frame;

signaling results of the entropy coding at frame level;

signaling the global luminance change parameters at frame level; and

if global luminance change is detected in the video frame, performing global luminance change compensation for at least part of the video frame, comprising adjusting plural pixel values in a reference video frame based at least in part on the global luminance change parameters.

6. The method of claim 5 further comprising:

signaling a value of a global luminance change compensation capability on/off signal for a sequence that includes the plural video frames.

7. The method of claim 5 wherein the results of the entropy coding comprise a variable length code that at least in part indicates both the value of the global luminance change compensation on/off signal for the video frame and the value of other frame-level information for the video frame.

8. The method of claim 5 wherein the results of the entropy coding comprise a variable length code selected from a single variable length code table with plural variable length codes.

9. The method of claim 8 wherein the variable length code is an escape code.

10. The method of claim 5 wherein the other frame-level information is motion mode information for the video frame.

11. The method of claim 5 wherein, if global luminance change compensation is on for the video frame, the results of the entropy coding are a first variable length code, a single bit following the first variable length code, and a second variable length code following the single bit, and wherein the single bit distinguishes a global luminance change compensation on signal from a least-frequently-occurring motion mode.

12. The method of claim 5 wherein, if global luminance change compensation is off for the video frame:

if motion mode for the video frame is a least-frequently-occurring motion mode, the results of the entropy coding are a variable length code and single bit that indicate the least-frequently-occurring motion mode for the video frame; and

otherwise, the results of the entropy coding are a variable length code that indicates the motion mode for the video frame.

13. A computer-readable medium storing computer-executable instructions for causing a computer system programmed thereby to perform the method of claim 5.

14. A computer-implemented method for transforming encoded video information using a computing device that implements a video decoder, the computing device comprising a processing unit and memory, the method comprising, during video decoding:

with the computing device that implements the video decoder;

for each of plural video frames,

receiving information at frame level, wherein the information comprises results of entropy coding of a value of a global luminance change compensation on/off signal for the video frame jointly with other frame-level information for the video frame;

from the received information, entropy decoding the value of the global luminance change compensation on/off signal and the other frame-level information for the video frame;

determining whether global luminance change compensation is on or off for the video frame based upon the global luminance change compensation on/off signal for the video frame;

if global luminance change compensation is on, receiving global luminance change parameters for the video frame; and

if global luminance change compensation is on, performing global luminance change compensation for at least part of the video frame, comprising adjusting plural pixel values in a reference video frame based at least in part on the global luminance change parameters.

15. The method of claim 14 further comprising:

receiving a value of a global luminance change compensation capability on/off signal for a sequence that includes the plural video frames.

16. The method of claim 14 wherein the results of the entropy coding comprise a variable length code that at least in part indicates both the value of the global luminance change compensation on/off signal for the video frame and the value of other frame-level information for the video frame.

17. The method of claim 14 wherein the results of the entropy coding comprise a variable length code selected from a single variable length code table with plural variable length codes.

18. The method of claim 17 wherein the variable length code is an escape code.

19. The method of claim 14 wherein the other frame-level information is motion mode information for the video frame.

20. The method of claim 14 wherein, if global luminance change compensation is on for the video frame, the results of the entropy coding are a first variable length code, a single bit following the first variable length code, and a second variable length code following the single bit, and wherein the single bit distinguishes a global luminance change compensation on signal from a least-frequently-occurring motion mode.

21. The method of claim 14 wherein, if global luminance change compensation is off for the video frame:

if motion mode for the video frame is a least-frequently-occurring motion mode, the results of the entropy coding are a variable length code and single bit that indicate the least-frequently-occurring motion mode for the video frame; and

otherwise, the results of the entropy coding are a variable length code that indicates the motion mode for the video frame.

22. A computer-readable medium storing computer-executable instructions for causing a computer system programmed thereby to perform the method of claim 14.

23. A computer-implemented method for transforming video information using a computing device that implements a video encoder, the computing device comprising a processing unit and memory, the method comprising, during video encoding:

with the computing device that implements the video encoder;

signaling, at a video sequence level, a fading compensation capability signal for a video sequence;

if fading compensation is enabled, signaling, at frame level, one or more fading compensation on/off signals for video frames in the video sequence, wherein fading parameters follow, at the frame level, the one or more fading compensation on/off signals; and

if fading compensation is enabled, performing fading compensation for at least part of a current video frame, comprising adjusting plural pixel values in a reference video frame based at least in part on the fading parameters.

24. The method of claim 23 wherein the one or more fading compensation on/off signals comprise one bit per video frame indicating whether or not fading compensation is used for that video frame.

25. The method of claim 23 wherein the one or more fading compensation on/off signals comprise one or more entropy codes per video frame, the one or more entropy codes jointly indicating whether or not fading compensation is used and other frame-level information.

26. A computer-readable medium storing computer-executable instructions for causing a computer system programmed thereby to perform the method of claim 23.

27. A method for transforming video information using a computing device that implements a video encoder, the computing device comprising a processing unit and memory, the method comprising, during video encoding:

with the computing device that implements the video encoder;

signaling a fading compensation flag at a first syntax level in a video sequence; and

when the fading compensation flag at the first syntax level indicates fading compensation is activated for a current video frame in the video sequence, signaling one or more fading parameters at a second syntax level lower than the first syntax level in the video sequence, wherein the one or more fading parameters are for fading compensation for at least part of the current video frame, and wherein the fading compensation comprises adjusting plural pixel values in a reference video frame based at least in part on the one or more fading parameters.

28. The method of claim 27 wherein the plural pixel values in the reference video frame comprise luminance values and chrominance values.

29. The method of claim 27 wherein the plural pixel values include all pixel values in the reference video frame.

30. The method of claim 27 wherein the first syntax level is sequence level and the second syntax level is frame level.

31. The method of claim 27 wherein the fading compensation comprises adjusting plural pixel values in multiple reference video frames.

32. A computer-readable medium storing computer-executable instructions for causing a computer system programmed thereby to perform the method of claim 27.

33. A method for transforming encoded video information using a computing device that implements a video decoder, the computing device comprising a processing unit and memory, the method comprising, during video decoding:

with the computing device that implements the video decoder;

receiving and processing a fading compensation flag at a first syntax level in a video sequence; and

when the fading compensation flag at the first syntax level indicates fading compensation is activated for a current video frame in the video sequence, receiving and processing one or more fading parameters at a second syntax level lower than the first syntax level in the video sequence, wherein the one or more fading parameters are for fading compensation for at least part of the current video frame, and wherein the fading compensation comprises adjusting plural pixel values in a reference video frame based at least in part on the one or more fading parameters.

34. The method of claim 33 wherein the plural pixel values in the reference video frame comprise luminance values and chrominance values.

35. The method of claim 33 wherein the plural pixel values include all pixel values in the reference video frame.

36. The method of claim 33 wherein the first syntax level is sequence level and the second syntax level is frame level.

37. The method of claim 33 wherein the fading compensation comprises adjusting plural pixel values in multiple reference video frames.

38. A computer-readable medium storing computer-executable instructions for causing a computer system programmed thereby to perform the method of claim 33.