DETERMINING NEIGHBORING SAMPLES FOR BILATERAL FILTERING IN VIDEO CODING

• US 20180184127A1
• Filed: 12/21/2017
• Published: 06/28/2018
• Est. Priority Date: 12/22/2016
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Zhang, Li, Chien, Wei-Jung, Karczewicz, Marta
• Application Number:
  US15/851,358
• Publication Number:
  US 20180184127A1
• Time in Patent Office: Days
• CPC Class Codes: H04N 19/117 Filters, e.g. for pre-processing or post-processing sub-band filter banks H04N19/635
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/157 Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter
• CPC Class Codes: H04N 19/159 Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/182 the unit being a pixel
• CPC Class Codes: H04N 19/197 including determination of the initial value of an encoding parameter H04N19/56 takes precedence
• CPC Class Codes: H04N 19/436 using parallelised computational arrangements
• CPC Class Codes: H04N 19/44 Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
• CPC Class Codes: H04N 19/463 by compressing encoding parameters before transmission
• CPC Class Codes: H04N 19/537 Motion estimation other than block-based
• CPC Class Codes: H04N 19/593 involving spatial prediction techniques
• 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 19/80 Details of filtering operations specially adapted for video compression, e.g. for pixel interpolation H04N19/635, H04N19/86 take precedence
• CPC Class Codes: H04N 19/82 involving filtering within a prediction loop
• CPC Class Codes: H04N 19/86 involving reduction of coding artifacts, e.g. of blockiness
• CPC Class Codes: H04N 19/91 Entropy coding, e.g. variable length coding [VLC] or arithmetic coding

Abstract

A device for decoding video data is configured to determine weights for use in a bilateral filter for a current block of a current picture of the video data; apply the bilateral filter to a current sample of the current block, wherein the current sample is located inside a transform unit boundary, wherein applying the bilateral filter to the current sample comprises: assigning the weights to neighboring samples of the current sample of the current block, wherein the neighboring samples of the current sample include a neighboring sample located outside the transform unit; and modifying a sample value for the current sample based on sample values of the neighboring samples and the weights assigned to the neighboring samples; and based on the modified sample value for the current sample, outputting a decoded version of the current picture.

Claims

1. A method for decoding video data, the method comprising:

for a current block of a current picture of the video data, determining weights for use in a bilateral filter;

applying the bilateral filter to a current sample of the current block, wherein the current sample is located inside a transform unit boundary, wherein applying the bilateral filter to the current sample comprises;

assigning the weights to neighboring samples of the current sample of the current block, wherein the neighboring samples of the current sample include a neighboring sample located outside the transform unit; and

modifying a sample value for the current sample based on sample values of the neighboring samples and the weights assigned to the neighboring samples; and

based on the modified sample value for the current sample, outputting a decoded version of the current picture.

2. The method of claim 1, further comprising:

determining that the neighboring sample located outside the transform unit boundary is available for the bilateral filter in response to the neighboring sample located outside the transform unit and the current sample being located in a same largest coding unit.

3. The method of claim 1, further comprising:

determining that the neighboring sample located outside the transform unit boundary is available for the bilateral filter in response to the neighboring sample located outside the transform unit and the current sample being located in a same largest coding unit row.

4. The method of claim 1, further comprising:

determining that the neighboring sample located outside the transform unit boundary is available for the bilateral filter in response to the neighboring sample located outside the transform unit boundary and the current sample being located in a same slice.

5. The method of claim 1, further comprising:

determining that the neighboring sample located outside the transform unit boundary is available for the bilateral filter in response to the neighboring sample located outside the transform unit and the current sample being located in a same tile.

6. The method of claim 1, further comprising:

determining that the neighboring sample located outside the transform unit boundary is unavailable for the bilateral filter; and

in response to determining that the neighboring sample located outside the transform unit boundary is unavailable for the bilateral filter, deriving a virtual sample value for the neighboring sample located outside the transform unit; and

wherein modifying the sample value for the current sample based on sample values of the neighboring samples and the weights assigned to the neighboring samples comprises modifying the sample value for the current sample based on the virtual sample value.

7. The method of claim 1, wherein the current block comprises a reconstructed block formed by adding a predictive block to a residual block, wherein the residual block defines the transform unit.

8. The method of claim 1, wherein a largest coding unit comprises a first coding unit and a second coding unit, and wherein the first coding unit comprises the current block and a transform unit associated with the current block, and wherein the transform unit defines the transform unit boundary.

9. The method of claim 1, wherein determining the weights for use in the bilateral filter comprises:

determining a value for a range parameter based on a quantization parameter for the current block;

determining a value for a spatial parameter based on a transform size of the current block; and

determining the weights for use in the bilateral filter based on the value for the range parameter and the value for the spatial parameter.

10. The method of claim 1, wherein the method of decoding is performed as part of a decoding loop of a video encoding process, the method further comprising:

after applying the bilateral filter to the current sample, using the decoded version of the current picture as a reference picture in encoding another picture of the video data.

11. The method of claim 1, wherein outputting the decoded version of the current picture comprises outputting the decoded version of the current picture to a display device.

12. A device for decoding video data, the device comprising:

one or more storage media configured to store the video data; and

one or more processors configured to;

for a current block of a current picture of the video data, determine weights for use in a bilateral filter;

apply the bilateral filter to a current sample of the current block, wherein the current sample is located inside a transform unit boundary, wherein to apply the bilateral filter to the current sample, the one or more processors are further configured to;

assign the weights to neighboring samples of the current sample of the current block, wherein the neighboring samples of the current sample include a neighboring sample located outside the transform unit; and

modify a sample value for the current sample based on sample values of the neighboring samples and the weights assigned to the neighboring samples; and

based on the modified sample value for the current sample, output a decoded version of the current picture.

13. The device of claim 12, wherein the one or more processors are further configured to:

determine that the neighboring sample located outside the transform unit boundary is available for the bilateral filter in response to the neighboring sample located outside the transform unit and the current sample being located in a same largest coding unit.

14. The device of claim 12, wherein the one or more processors are further configured to:

determine that the neighboring sample located outside the transform unit boundary is available for the bilateral filter in response to the neighboring sample located outside the transform unit and the current sample being located in a same largest coding unit row.

15. The device of claim 12, wherein the one or more processors are further configured to:

determine that the neighboring sample located outside the transform unit boundary is available for the bilateral filter in response to the neighboring sample located outside the transform unit boundary and the current sample being located in a same slice.

16. The device of claim 12, wherein the one or more processors are further configured to:

determine that the neighboring sample located outside the transform unit boundary is available for the bilateral filter in response to the neighboring sample located outside the transform unit and the current sample being located in a same tile.

17. The device of claim 12, wherein the one or more processors are further configured to:

determine that the neighboring sample located outside the transform unit boundary is unavailable for the bilateral filter; and

in response to determining that the neighboring sample located outside the transform unit boundary is unavailable for the bilateral filter, derive a virtual sample value for the neighboring sample located outside the transform unit; and

wherein to modify the sample value for the current sample based on sample values of the neighboring samples and the weights assigned to the neighboring samples, the one or more processors are further configured to modify the sample value for the current sample based on the virtual sample value.

18. The device of claim 12, wherein the current block comprises a reconstructed block formed by adding a predictive block to a residual block, wherein the residual block defines the transform unit.

19. The device of claim 12, wherein a largest coding unit comprises a first coding unit and a second coding unit, and wherein the first coding unit comprises the current block and a transform unit associated with the current block, and wherein the transform unit defines the transform unit boundary.

20. The device of claim 12, wherein to determine the weights for use in the bilateral filter, the one or more processors are further configured to:

determine a value for a range parameter based on a quantization parameter for the current block;

determine a value for a spatial parameter based on a transform size of the current block; and

determine the weights for use in the bilateral filter based on the value for the range parameter and the value for the spatial parameter.

21. The device of claim 12, wherein to output the decoded version of the current picture, the one or more processors are further configured to output the decoded version of the current picture to a display device.

22. The device of claim 12, wherein the one or more processors are configured to:

decode the video data as part of a decoding loop of a video encoding process; and

after applying the bilateral filter to the current sample, use the decoded version of the current picture as a reference picture in encoding another picture of the video data.

23. The device of claim 22, wherein the device comprises a wireless communication device, further comprising a transmitter configured to transmit encoded video data.

24. The device of claim 23, wherein the wireless communication device comprises a telephone handset and wherein the transmitter is configured to modulate, according to a wireless communication standard, a signal comprising the encoded video data.

25. The device of claim 12, wherein the device comprises a wireless communication device, further comprising a receiver configured to receive encoded video data.

26. The device of claim 25, wherein the wireless communication device comprises a telephone handset and wherein the receiver is configured to demodulate, according to a wireless communication standard, a signal comprising the encoded video data.

27. A computer readable storage medium storing instructions that when executed by one or more processors cause the one or more processors to:

for a current block of a current picture of the video data, determine weights for use in a bilateral filter;

apply the bilateral filter to a current sample of the current block, wherein the current sample is located inside a transform unit boundary, wherein to apply the bilateral filter to the current sample, the instructions cause the one or more processors to;

assign the weights to neighboring samples of the current sample of the current block, wherein the neighboring samples of the current sample include a neighboring sample located outside the transform unit; and

modify a sample value for the current sample based on sample values of the neighboring samples and the weights assigned to the neighboring samples; and

based on the modified sample value for the current sample, output a decoded version of the current picture.

28. The computer readable storage medium of claim 27 storing further instructions that when executed the by the one or more processors cause the one or more processors to:

determine that the neighboring sample located outside the transform unit boundary is available for the bilateral filter in response to the neighboring sample located outside the transform unit and the current sample being located in a same largest coding unit.

29. The computer readable storage medium of claim 27 storing further instructions that when executed the by the one or more processors cause the one or more processors to:

determine that the neighboring sample located outside the transform unit boundary is available for the bilateral filter in response to the neighboring sample located outside the transform unit and the current sample being located in a same largest coding unit row.

30. The computer readable storage medium of claim 27 storing further instructions that when executed the by the one or more processors cause the one or more processors to:

determine that the neighboring sample located outside the transform unit boundary is available for the bilateral filter in response to the neighboring sample located outside the transform unit boundary and the current sample being located in a same slice.

31. The computer readable storage medium of claim 27 storing further instructions that when executed the by the one or more processors cause the one or more processors to:

determine that the neighboring sample located outside the transform unit boundary is available for the bilateral filter in response to the neighboring sample located outside the transform unit and the current sample being located in a same tile.

32. The computer readable storage medium of claim 27 storing further instructions that when executed the by the one or more processors cause the one or more processors to:

determine that the neighboring sample located outside the transform unit boundary is unavailable for the bilateral filter; and

in response to determining that the neighboring sample located outside the transform unit boundary is unavailable for the bilateral filter, derive a virtual sample value for the neighboring sample located outside the transform unit; and

wherein to modify the sample value for the current sample based on sample values of the neighboring samples and the weights assigned to the neighboring samples, the instructions cause the one or more processors to modify the sample value for the current sample based on the virtual sample value.

33. The computer readable storage medium of claim 27, wherein the current block comprises a reconstructed block formed by adding a predictive block to a residual block, wherein the residual block defines the transform unit.

34. The computer readable storage medium of claim 27, wherein a largest coding unit comprises a first coding unit and a second coding unit, and wherein the first coding unit comprises the current block and a transform unit associated with the current block, and wherein the transform unit defines the transform unit boundary.

35. The computer readable storage medium of claim 27 storing further instructions that when executed the by the one or more processors cause the one or more processors to:

determine a value for a range parameter based on a quantization parameter for the current block;

determine a value for a spatial parameter based on a transform size of the current block; and

determine the weights for use in the bilateral filter based on the value for the range parameter and the value for the spatial parameter.

36. An apparatus for decoding video data, the apparatus comprising:

means for determining weights for use in a bilateral filter for a current block of a current picture of the video data;

means for applying the bilateral filter to a current sample of the current block, wherein the current sample is located inside a transform unit boundary, wherein the means for applying the bilateral filter to the current sample comprises;

means for assigning the weights to neighboring samples of the current sample of the current block, wherein the neighboring samples of the current sample include a neighboring sample located outside the transform unit; and

means for modifying a sample value for the current sample based on sample values of the neighboring samples and the weights assigned to the neighboring samples; and

means for outputting a decoded version of the current picture based on the modified sample value for the current sample.