Block-Based Predictive Coding and Decoding of a Picture

• US 20190327492A1
• Filed: 07/03/2019
• Published: 10/24/2019
• Est. Priority Date: 01/05/2017
• Status: Active Grant

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: PFAFF, Jonathan, WINKEN, Martin, RUDAT, Christian, SCHWARZ, Heiko, WIEGAND, Thomas, MARPE, Detlev
• Granted Patent: US 11,115,682 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04N 19/13 Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC]
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/48 using compressed domain processing techniques other than decoding, e.g. modification of transform coefficients, variable length coding [VLC] data or run-length data motion estimation in a transform domain H04N19/547; processing of decoded motion vectors H04N19/513
• CPC Class Codes: H04N 19/60 using transform coding
• CPC Class Codes: H04N 19/65 using error resilience
• CPC Class Codes: H04N 19/82 involving filtering within a prediction loop

Abstract

A previously encoded or reconstructed version of a neighborhood of a predetermined block to be predicted is exploited so as to result into a more efficient predictive coding of the prediction block. In particular, a spectral decomposition of a region composed of this neighborhood and a first version of a predicted filling of the predetermined block results into a first spectrum which is subject to noise reduction and the thus resulting second spectrum may be subject to a specral composition, thereby resulting in a modified version of this region including a second version of the predicted filling of the predetermined block. Owing to the exploitation of the already processed, i.e. encoded/reconstructed, neighborhood of the predetermined block, the second version of the predicted filling of the predetermined block tends to improve the coding efficiency.

Claims

1. An apparatus for block-based predictive decoding of a picture, comprising:

a prediction provider configured to predict a predetermined block of the picture to acquire a first version of a predicted filling of the predetermined block;

a spectral decomposer configured to spectrally decompose a region composed of the first version of the predicted filling of the predetermined block and a reconstructed version of a neighborhood of the predetermined block so as to acquire a first spectrum of the region;

a noise reducer configured to perform noise reduction on the first spectrum to acquire a second spectrum;

a spectral composer configured to subject the second spectrum to spectral composition so as to acquire a modified version of the region including a second version of the predicted filling of the predetermined block;

a reconstructor configured to decode a reconstructed version of the predetermined block from a data stream on the basis of the second version of the predicted filling.

2. The apparatus according to claim 1, wherein the prediction provider is configured to predict the predetermined block using spatial and/or temporal prediction.

3. The apparatus according to claim 1, wherein the spectral decomposer is configured such that the neighborhood of the predetermined block is a spatial extension of the predetermined block beyond a contiguous half of a circumference of the predetermined block.

4. The apparatus according to claim 1, wherein the predetermined block is rectangular and the circumference of the predetermined block comprises a first, second, third and fourth side sequentially arranged along the circumference of the predetermined block clockwise, wherein the contiguous half comprises the first and fourth sides.

5. The apparatus according to claim 4, wherein the region is rectangular and the circumference of the region includes the second and third sides of the predetermined block.

6. The apparatus according to claim 1, wherein the spectral decomposer and the spectral composer are configured such that the spectral decomposition and the spectral composition are mutually inverse with the spectral decomposition being a DST, DCT or wavelet transform.

7. The apparatus according to claim 1, wherein the noise reducer is configured to subject the first spectrum to thresholding.

8. The apparatus according to claim 1, wherein the reconstructor is configured to decode a residual signal from the data stream and correct the second version of the predicted filling of the predetermined block using the residual signal.

9. The apparatus according to claim 1, wherein the reconstructor is configured to decode the residual signal from the data stream in a spectral domain, transform the residual signal into spatial domain and perform the correction in the spatial domain.

10. The apparatus according to claim 9, wherein the reconstructor is configured to perform the transforming of the residual signal using a transform type also used by the spectral composer for the spectral composition.

11. The apparatus according to claim 1, wherein the reconstructor is configured to switch between using the first version of the predicted filling and the second version of the predicted filling depending on a first signalization in the data stream.

12. The apparatus according to claim 11, wherein the apparatus is configured to decode the first signalization from the data stream at sub-picture granularity.

13. The apparatus according to claim 11, wherein the apparatus is configured to decode the first signalization from the data stream using spatial prediction and/or using entropy decoding using a spatially depending context.

14. The apparatus according to claim 1, wherein the spectral decomposer is configured to set a size of the neighborhood depending on a second signalization in the data stream.

15. The apparatus according to claim 14, wherein the apparatus is configured to decode the second signalization from the data stream at sub-picture granularity.

16. The apparatus according to claim 14, wherein the apparatus is configured to decode the second signalization from the data stream using spatial prediction and/or using entropy decoding using a spatially depending context.

17. The apparatus according to claim 1, wherein the noise reducer is configured to set a strength of the noise reduction depending on a third signalization in the data stream.

18. The apparatus according to claim 17, wherein the apparatus is configured to decode the third signalization from the data stream at sub-picture granularity.

19. The apparatus according to claim 17, wherein the apparatus is configured to decode the third signalization from the data stream using spatial prediction and/or using entropy decoding using a spatially depending context.

20. The apparatus according to claim 17, wherein the apparatus is configured to, in setting a strength of the noise reduction, select a set of possible strengths on the basis of a quantization parameter applied by the reconstructor for reconstructing the predetermined block from the data stream and perform the setting so that the strength is set to one of the set of possible strengths by using the third signalization as an index into the selected set of possible strengths.

21. An apparatus for block-based predictive encoding of a picture, comprising:

a prediction provider configured to predict a predetermined block of the picture to acquire a first version of a predicted filling of the predetermined block;

a spectral decomposer configured to spectrally decompose a region composed of the first version of the predicted filling of the predetermined block and a previously encoded version of a neighborhood of the predetermined block so as to acquire a first spectrum of the region;

a noise reducer configured to perform noise reduction on the first spectrum to acquire a second spectrum;

a spectral composer configured to subject the second spectrum to spectral composition so as to acquire a modified version of the region including a second version of the predicted filling of the predetermined block;

an encoding stage configured to encode the predetermined block into a data stream on the basis of the second version of the predicted filling.

22. The apparatus according to claim 21, wherein the prediction provider is configured to predict the predetermined block using spatial and/or temporal prediction.

23. The apparatus according to claim 21, wherein the spectral decomposer is configured such that the neighborhood of the predetermined block is a spatial extension of the predetermined block beyond a contiguous half of a circumference of the predetermined block.

24. The apparatus according to claim 21, wherein the predetermined block is rectangular and the circumference of the predetermined block comprises a first, second, third and fourth side sequentially arranged along the circumference of the predetermined block clock-wise, wherein the contiguous half comprises the first and fourth sides.

25. The apparatus according to claim 24, wherein the region is rectangular and the circumference of the region comprises the second and third sides of the predetermined block.

26. The apparatus according to claim 21, wherein the spectral decomposer and the spectral composer are configured such that the spectral decomposition and the spectral composition are mutually inverse with the spectral decomposition being a DST, DCT or wavelet transform.

27. The apparatus according to claim 21, wherein the noise reducer is configured to subject the first spectrum to thresholding.

28. The apparatus according to claim 21, wherein the encoding stage is configured to encode a residual signal into a data stream, the residual signal correcting a prediction error of the second version of the predicted filling of the predetermined block.

29. The apparatus according to claim 21, wherein the encoding stage is configured to determine the prediction error in spatial domain, transform the prediction error into spectral domain and encode the residual signal into the data stream in the spectral domain.

30. The apparatus according to claim 29, wherein the encoding stage is configured to perform the transforming of the residual signal using a transform type also used by the spectral decomposer for the spectral decomposition.

31. The apparatus according to claim 21, wherein the encoding stage is configured to select between using the first version of the predicted filling and the second version of the predicted filling and signal the selection by way of a first signalization in the data stream.

32. The apparatus according to claim 31, wherein the apparatus is configured to perform the selection and encode the first signalization into the data stream at sub-picture granularity.

33. The apparatus according to claim 32, wherein the apparatus is configured to encode the first signalization into the data stream using spatial prediction and/or using entropy encoding using a spatial context.

34. The apparatus according to claim 21, configured to set a size of neighborhood and signalize the size by way of a second signalization in a data stream.

35. The apparatus according to claim 34, wherein the apparatus is configured to perform the setting and encode the second signalization into the data stream at sub-picture granularity.

36. The apparatus according to claim 34, wherein the apparatus is configured to encode the second signalization into the data stream using spatial prediction and/or using entropy encoding using a spatial context.

37. The apparatus according to claim 21, configured to set a strength of the noise reduction and signalize the strength by way of a third signalization in the data stream.

38. The apparatus according to claim 37, wherein the apparatus is configured to perform the setting of the strength and encode the third signalization into the data stream at sub-picture granularity.

39. The apparatus according to claim 37, wherein the apparatus is configured to encode the third signalization into the data stream using spatial prediction and/or using entropy encoding using a spatial context.

40. The apparatus according to claim 37, wherein the apparatus is configured to, in setting a strength of the noise reduction, select a set of possible strengths on the basis of a quantization parameter applied by encoding stage for encoding the predetermined block into the data stream and perform the setting so that the strength is set to one of the set of possible strengths and the third signalization indicates an index into the selected set of possible strengths.

41. A method for block-based predictive decoding of a picture, comprising:

predicting a predetermined block of the picture to acquire a first version of a predicted filling of the predetermined block;

spectrally decomposing a region composed of the first version of the predicted filling of the predetermined block and a reconstructed version of a neighborhood of the predetermined block so as to acquire a first spectrum of the region;

performing noise reduction on the first spectrum to acquire a second spectrum;

subjecting the second spectrum to spectral composition so as to acquire a modified version of the region including a second version of the predicted filling of the predetermined block;

decoding a reconstructed version of the predetermined block from a data stream on the basis of the second version of the predicted filling.

42. A method for block-based predictive encoding of a picture, comprising:

predicting a predetermined block of the picture to acquire a first version of a predicted filling of the predetermined block;

spectrally decomposing a region composed of the first version of the predicted filling of the predetermined block and a previously encoded version of a neighborhood of the predetermined block so as to acquire a first spectrum of the region;

performing noise reduction on the first spectrum to acquire a second spectrum;

subjecting the second spectrum to spectral composition so as to acquire a modified version of the region including a second version of the predicted filling of the predetermined block;

encoding the predetermined block into a data stream on the basis of the second version of the predicted filling.

45. A data stream having a picture encoded thereinto, the data stream being generated by a method according to claim 42.

43. A non-transitory digital storage medium having a computer program stored thereon to perform the method for block-based predictive decoding of a picture, the method comprising:

predicting a predetermined block of the picture to acquire a first version of a predicted filling of the predetermined block;

spectrally decomposing a region composed of the first version of the predicted filling of the predetermined block and a reconstructed version of a neighborhood of the predetermined block so as to acquire a first spectrum of the region;

performing noise reduction on the first spectrum to acquire a second spectrum;

subjecting the second spectrum to spectral composition so as to acquire a modified version of the region including a second version of the predicted filling of the predetermined block;

decoding a reconstructed version of the predetermined block from a data stream on the basis of the second version of the predicted filling,

when said computer program is run by a computer

44. A non-transitory digital storage medium having a computer program stored thereon to perform the method for block-based predictive encoding of a picture, the method comprising:

predicting a predetermined block of the picture to acquire a first version of a predicted filling of the predetermined block;

spectrally decomposing a region composed of the first version of the predicted filling of the predetermined block and a previously encoded version of a neighborhood of the predetermined block so as to acquire a first spectrum of the region;

performing noise reduction on the first spectrum to acquire a second spectrum;

subjecting the second spectrum to spectral composition so as to acquire a modified version of the region including a second version of the predicted filling of the predetermined block;

encoding the predetermined block into a data stream on the basis of the second version of the predicted filling,

when said computer program is run by a computer.