DEBLOCK FILTERING FOR INTRA BLOCK COPYING

• US 20160100163A1
• Filed: 09/21/2015
• Published: 04/07/2016
• Est. Priority Date: 10/07/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Rapaka, Krishnakanth, Sole Rojals, Joel, Hsieh, Cheng-Teh, Seregin, Vadim, Karczewicz, Marta, Pang, Chao
• Granted Patent: US 9,832,467 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 19/159 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 19/513 Processing of motion vectors
• CPC Class Codes: H04N 19/593 involving spatial prediction techniques
• 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

Abstract

Techniques are described for determining boundary strength value for an intra-block copy (IBC)-coded block and for selective storage of unfiltered pixel values of a region of a picture based on whether the region will be used as reference for IBC coding.

Claims

1. A method of processing video data, the method comprising:

determining a coding mode of a current block in a picture of the video data and a coding mode of a neighboring block in the picture of the video data;

performing a boundary strength value determination process based on one of the current block or the neighboring block being an intra-block copy (IBC)-coded block and the other block being an inter-coded block to determine a boundary strength value, wherein the boundary strength value determination process does not include identifying a motion vector for the inter-coded block, and wherein the boundary strength value determination process is different than a boundary strength value determination process where one of the current block or the neighboring block is intra-coded and the other is IBC-coded; and

deblock filtering along an edge between the current block and the neighboring block based on the determined boundary strength value.

2. The method of claim 1, wherein the boundary strength value determination process is the same boundary strength value determination process where both the current block and the neighboring block are IBC-coded blocks.

3. The method of claim 1, wherein performing the boundary strength value determination process comprises setting the boundary strength value equal to one.

4. The method of claim 1, wherein performing the boundary strength value determination process comprises:

determining a reference block for the IBC-coded block;

determining whether any pixel in the reference block is coded in intra-prediction mode or IBC mode;

setting the boundary strength value equal to two based on any pixel in the reference block being coded in intra-prediction mode or IBC mode;

or

setting the boundary strength value equal to one based on no pixel in the reference block being coded in intra-prediction mode or IBC mode.

5. The method of claim 1, further comprising:

determining whether a region in the picture is referenced for prediction using IBC mode for at least one block in the picture;

storing unfiltered pixel values for the region in the picture based on a determination that the region is referenced for prediction using IBC mode; and

avoiding the storing of unfiltered pixel values for the region in the picture based on a determination that the region is not referenced for prediction using IBC mode.

6. The method of claim 5, wherein each region comprises one of:

a picture, a tile, a slice, a prediction unit (PU) block, a coding unit (CU), a coding tree block (CTB), a group of CTBs, a fixed size of N×

N, or rectangular partitions of M×

N.

7. The method of claim 5, further comprising:

receiving information in one or more of a video parameter set (VPS), a sequence parameter set (SPS), a picture parameter set (PPS), slice header, parameter set extensions, or a supplemental enhancement information (SEI) message,

wherein determining whether the region in the picture is referenced for prediction using IBC mode for at least one block in the picture comprises determining based on received information in one or more of the VPS, SPS, PPS, slice header, parameter set extension, or SEI message.

8. The method of claim 5, further comprising:

outputting information in one or more of a video parameter set (VPS), sequence parameter set (SPS), picture parameter set (PPS), slice header, parameter set extensions, or supplemental enhancement information (SEI) message, wherein the information identifies whether the region in the picture is referenced for prediction using IBC mode for at least one block in the picture.

9. A device for processing video data, the device comprising:

a memory configured to store a neighboring block of the video data; and

a video coder configured to;

determine a coding mode of a current block in a picture of the video data and a coding mode of the neighboring block in the picture of the video data;

perform a boundary strength value determination process based on one of the current block or the neighboring block being an intra-block copy (IBC)-coded block and the other block being an inter-coded block to determine a boundary strength value, wherein the boundary strength value determination process does not include identifying a motion vector for the inter-coded block, and wherein the boundary strength value determination process is different than a boundary strength value determination process where one of the current block or the neighboring block is intra-coded and the other is IBC-coded; and

deblock filter along an edge between the current block and the neighboring block based on the determined boundary strength value.

10. The device of claim 9, wherein the boundary strength value determination process is the same boundary strength value determination process where both the current block and the neighboring block are IBC-coded blocks.

11. The device of claim 9, wherein to perform the boundary strength value determination process, the video coder is configured to set the boundary strength value equal to one.

12. The device of claim 9, wherein to perform the boundary strength value determination process, the video coder is configured to:

determine a reference block for the IBC-coded block;

determine whether any pixel in the reference block is coded in intra-prediction mode or IBC mode;

set the boundary strength value equal to two based on any pixel in the reference block being coded in intra-prediction mode or IBC mode;

or

set the boundary strength value equal to one based on no pixel in the reference block being coded in intra-prediction mode or IBC mode.

13. The device of claim 9, wherein the video coder is configured to:

determine whether a region in the picture is referenced for prediction using IBC mode for at least one block in the picture;

store in the memory unit unfiltered pixel values for the region in the picture based on a determination that the region is referenced for prediction using IBC mode; and

avoid the storing of unfiltered pixel values for the region in the picture based on a determination that the region is not referenced for prediction using IBC mode.

14. The device of claim 13, wherein each region comprises one of:

a picture, a tile, a slice, a prediction unit (PU) block, a coding unit (CU), a coding tree block (CTB), a group of CTBs, a fixed size of N×

N, or rectangular partitions of M×

N.

15. The device of claim 13, wherein the video coder comprises a video decoder, and wherein the video decoder is configured to:

receive information in one or more of a video parameter set (VPS), a sequence parameter set (SPS), a picture parameter set (PPS), slice header, or a supplemental enhancement information (SEI) message,

wherein to determine whether the region in the picture is referenced for prediction using IBC mode for at least one block in the picture, the video decoder is configured to determine based on received information in one or more of the VPS, SPS, PPS, slice header, or SEI message.

16. The device of claim 13, wherein the video coder comprises a video encoder, and wherein the video encoder is configured to:

output information in one or more of a video parameter set (VPS), sequence parameter set (SPS), picture parameter set (PPS), slice header, or supplemental enhancement information (SEI) message, wherein the information identifies whether the region in the picture is referenced for prediction using IBC mode for at least one block in the picture.

17. The device of claim 9, wherein the device comprises one or more of:

an integrated circuit (IC);

a microprocessor;

or

a wireless communication device that includes at least one of a camera to capture the picture or a display to display the picture.

18. A non-transitory computer-readable storage medium having instructions stored thereon that when executed cause one or more processors of a device for processing video data to:

determine a coding mode of a current block in a picture of the video data and a coding mode of a neighboring block in the picture of the video data;

perform a boundary strength value determination process based on one of the current block or the neighboring block being an intra-block copy (IBC)-coded block and the other block being an inter-coded block to determine a boundary strength value, wherein the boundary strength value determination process does not include identifying a motion vector for the inter-coded block, and wherein the boundary strength value determination process is different than a boundary strength value determination process where one of the current block or the neighboring block is intra-coded and the other is IBC-coded; and

deblock filter along an edge between the current block and the neighboring block based on the determined boundary strength value.

19. The non-transitory computer-readable storage medium of claim 18, wherein the boundary strength value determination process is the same boundary strength value determination process where both the current block and the neighboring block are IBC-coded blocks.

20. The non-transitory computer-readable storage medium of claim 18, wherein the instructions that cause the one or more processors to perform the boundary strength value determination process comprise instructions that cause the one or more processors to set the boundary strength value equal to one.

21. The non-transitory computer-readable storage medium of claim 18, wherein the instructions that cause the one or more processors to perform the boundary strength value determination process comprise instructions that cause the one or more processors to:

determine a reference block for the IBC-coded block;

determine whether any pixel in the reference block is coded in intra-prediction mode or IBC mode;

set the boundary strength value equal to two based on any pixel in the reference block being coded in intra-prediction mode or IBC mode;

or

set the boundary strength value equal to one based on no pixel in the reference block being coded in intra-prediction mode or IBC mode.

22. The non-transitory computer-readable storage medium of claim 18, further comprising instructions that cause the one or more processors to:

determine whether a region in the picture is referenced for prediction using IBC mode for at least one block in the picture;

store unfiltered pixel values for the region in the picture based on a determination that the region is referenced for prediction using IBC mode; and

avoid the storing of unfiltered pixel values for the region in the picture based on a determination that the region is not referenced for prediction using IBC mode.

23. A device for processing video data, the device comprising:

means for determining a coding mode of a current block in a picture of the video data and a coding mode of a neighboring block in the picture of the video data;

means for performing a boundary strength value determination process based on one of the current block or the neighboring block being an intra-block copy (IBC)-coded block and the other block being an inter-coded block to determine a boundary strength value, wherein the boundary strength value determination process does not include identifying a motion vector for the inter-coded block, and wherein the boundary strength value determination process is different than a boundary strength value determination process where one of the current block or the neighboring block is intra-coded and the other is IBC-coded; and

means for deblock filtering along an edge between the current block and the neighboring block based on the determined boundary strength value.

24. The device of claim 23, wherein the boundary strength value determination process is the same boundary strength value determination process where both the current block and the neighboring block are IBC-coded blocks.

25. The device of claim 23, wherein the means for performing the boundary strength value determination process comprises means for setting the boundary strength value equal to one.

26. The device of claim 23, wherein the means for performing the boundary strength value determination process comprises:

means for determining a reference block for the IBC-coded block;

means for determining whether any pixel in the reference block is coded in intra-prediction mode or IBC mode;

means for setting the boundary strength value equal to two based on any pixel in the reference block being coded in intra-prediction mode or IBC mode;

or

means for setting the boundary strength value equal to one based on no pixel in the reference block being coded in intra-prediction mode or IBC mode.

27. The device of claim 23, further comprising:

means for determining whether a region in the picture is referenced for prediction using IBC mode for at least one block in the picture;

means for storing unfiltered pixel values for the region in the picture based on a determination that the region is referenced for prediction using IBC mode; and

means for avoiding the storing of unfiltered pixel values for the region in the picture based on a determination that the region is not referenced for prediction using IBC mode.