Signaling for fading compensation

• US 20030206583A1
• Filed: 03/03/2003
• Published: 11/06/2003
• Est. Priority Date: 05/03/2002
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Srinivasan, Sridhar, Regunathan, Shankar
• Granted Patent: US 7,609,767 B2
• Time in Patent Office: Days
• US Class Current: 375/240.01
• 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. In a computer system, a computer-implemented method comprising:

for each of plural video frames, processing a global luminance change compensation on/off signal for the video frame, wherein the global luminance change compensation on/off signal for the video frame is jointly entropy encoded with other frame-level information for the video frame.

2. The method of claim 1 wherein the other frame-level information is motion mode information for the video frame.

3. The method of claim 2 wherein a single bit following an escape code distinguishes a global luminance change compensation on signal from a least frequent motion mode.

4. The method of claim 1 further comprising:

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

5. The method of claim 1 further comprising:

during encoding,

determining a value for the global luminance change compensation on/off signal depending on whether global luminance change compensation is used for the video frame; and

transmitting the global luminance change compensation on/off signal and the other frame-level information.

6. The method of claim 5 further comprising:

before the determining the value, for at least one of the plural video frames,

detecting fading in the video frame; and

estimating global luminance change parameters for the video frame, wherein the global luminance change parameters are transmitted after the other frame-level information.

7. A computer-readable medium storing computer-executable instructions for causing the computer system to perform the method of claim 1 during video encoding.

8. The method of claim 1 further comprising:

during decoding, for each of the plural video frames, before the processing, receiving the global luminance change compensation on/off signal for the video frame, wherein the processing comprises 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.

9. A computer-readable medium storing computer-executable instructions for causing the computer system to perform the method of claim 1 during video decoding.

10. In a computer system, a computer-implemented method of processing one or more video images, the method comprising:

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

if fading compensation is enabled, processing, at an image level, one or more fading compensation on/off signals for video images in the video image sequence.

11. The method of claim 10 wherein the image-level signal comprises one bit per video image indicating whether fading compensation is absent for each video image.

12. The method of claim 10 wherein the image-level signal comprises one or more entropy codes jointly indicating whether fading compensation is present for a video image along with other image-level information.

13. The method of claim 12 wherein fading parameters follow the one or more entropy codes.

14. A computer-readable medium storing computer-executable instructions for causing the computer system to perform the method of claim 10 during video decoding.

15. A computer-readable medium storing computer-executable instructions for causing the computer system to perform the method of claim 10 during video encoding.

16. A computer-readable medium storing computer-executable instructions for causing a computer system programmed thereby to perform a computer-implemented method comprising:

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 image in the video sequence, 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 image, and wherein the fading compensation comprises adjusting plural pixel values in a reference video image based at least in part on the one or more fading parameters.

17. The computer-readable medium of claim 16 wherein the plural pixel values in the reference video image comprise luminance values and/or chrominance values.

18. The computer-readable medium of claim 16 wherein the current video image and the reference video image are video frames.

19. The computer-readable medium of claim 16 wherein the plural pixel values include all pixel values in the reference video image.

20. The computer-readable medium of claim 16 wherein the first syntax level is sequence level and the second syntax level is image level.

21. The computer-readable medium of claim 16 wherein the first syntax level is sequence level and the second syntax level is macroblock level.

22. The computer-readable medium of claim 16 wherein the processing the flag and the processing fading parameters occur during decoding.

23. The computer-readable medium of claim 16 wherein the processing the flag and the processing fading parameters occur during encoding.

24. A computer-readable medium storing computer-executable instructions for causing a computer system programmed thereby to perform a computer-implemented method comprising:

for each of plural video images in a video sequence, processing a fading compensation on/off signal at image syntax level in a bitstream for the video sequence, wherein if fading compensation is activated, plural fading parameters follow the fading compensation on/off signal in the bitstream, wherein the plural fading parameters are for fading compensation for at least part of the video image, and wherein the fading compensation comprises adjusting plural pixel values in a reference video image based at least in part the plural fading parameters.

25. The computer-readable medium of claim 24 wherein, for each of the plural video images in a video sequence, one or more entropy codes jointly represent the fading compensation on/off signal for the video image along with other image syntax level information for the video image.

26. The computer-readable medium of claim 24 wherein, for each of the plural video images in a video sequence, one or more entropy codes jointly represent the fading compensation on/off signal for the video image as well as motion mode information for the video image.

27. The computer-readable medium of claim 26 wherein, for at least one of the plural video images, a single bit following a first entropy code distinguishes a fading compensation on signal from a least frequent motion mode signal, and wherein the first entropy code is an escape code.

28. The computer-readable medium of claim 27 wherein a second entropy code following the one bit indicates a motion mode signal for the video image when fading compensation is on.

29. The computer-readable medium of claim 24 wherein the video image is a video frame, video field, video object plane, or macroblock.

30. The computer-readable medium of claim 24 wherein the processing occurs during decoding.

31. The computer-readable medium of claim 24 wherein the processing occurs during encoding.

32. The computer-readable medium of claim 24 wherein the method further comprises, for at least one of the plural video images, processing plural fading parameters, and wherein the plural fading parameters are fixed length coded.

33. The computer-readable medium of claim 24 wherein the method further comprises, for at least one of the plural video images, processing plural fading parameters, and wherein the plural fading parameters are variable length coded.

34. A computer-readable medium storing computer-executable instructions for causing a computer system programmed thereby to perform a computer-implemented method comprising:

for at least one portion of at least one video image in a video sequence, processing a fading compensation on/off signal at a syntax level below image level in a bitstream, wherein if fading compensation is activated, plural fading parameters follow the fading compensation on/off signal in the bitstream, and wherein the fading compensation comprises adjusting plural pixel values in a reference video image based at least in part the plural fading parameters.

35. The computer-readable medium of claim 34 wherein the syntax level below image level is macroblock level, and wherein one or more entropy codes jointly represent the fading compensation on/off signal along with other information for the at least one portion of the at least one video image.

36. The computer-readable medium of claim 35 wherein the other information is coded block pattern information or transform type information.

37. The computer-readable medium of claim 34 wherein the processing occurs during decoding.

38. The computer-readable medium of claim 34 wherein the processing occurs during encoding.

39. The computer-readable medium of claim 34 wherein the method further comprises, for the at least one portion of the at least one video image, processing plural fading parameters.