Filtering blockiness artifacts for video coding

Patent metadata

Field	Value
Publication number	US-9338476-B2
Application number	US-201213466831-A
Country	US
Kind code	B2
Filing date	May 8, 2012
Priority date	May 12, 2011
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

In one example, an apparatus for coding video data includes a video coder configured to determine a first prediction mode for a first block of video data and a second prediction mode for a second block of video data, wherein the first block and the second block share a common edge, decode the first block using the first prediction mode and the second block using the second prediction mode, and determine whether to deblock the common edge between the first block and the second block based at least in part on whether at least one of the first prediction mode and the second prediction mode comprises short distance intra-prediction (SDIP).

First claim

What is claimed is:

1. A method of coding video data, the method comprising:
determining a first prediction mode for a first block of video data and a second prediction mode for a second block of video data, wherein the first block and the second block share a common edge;
decoding the first block using the first prediction mode and the second block using the second prediction mode; and
determining whether to deblock the common edge between the first block and the second block based at least in part on whether at least one of the first prediction mode or the second prediction mode comprises short distance intra-prediction (SDIP), wherein determining whether to deblock the common edge comprises, when at least one of the first prediction mode and the second prediction mode comprises SDIP:
determining whether SDIP prediction units (PUs) are oriented perpendicular to the common edge;
applying a first deblocking decision function to an equal number of support pixels on either side of the common edge when all of the SDIP PUs are oriented perpendicular to the common edge;
applying a second, different deblocking decision function to an adapted set of support pixels when at least one of the SDIP PUs is oriented parallel to the common edge; and
deblocking the common edge when the second deblocking decision function indicates that the common edge is to be deblocked.

2. The method of claim 1 , further comprising, after determining to deblock the common edge, determining a deblocking filter to deblock the common edge based at least in part on whether at least one of the first prediction mode or the second prediction mode comprises SDIP.

3. The method of claim 2 , wherein determining the deblocking filter comprises, when at least one of the first prediction mode or the second prediction mode comprises SDIP:
determining whether the SDIP PUs are oriented perpendicular to the common edge; and
selecting a deblocking filter having coefficients that can be applied to an equal number of support pixels on either side of the common edge when all of the SDIP PUs are oriented perpendicular to the common edge.

4. The method of claim 1 , wherein determining whether to deblock the common edge comprises determining not to deblock the edge when at least one of the first prediction mode or the second prediction mode comprises SDIP.

5. The method of claim 1 , wherein determining whether to deblock the common edge comprises selecting an adapted set of support to which to apply a deblocking decision function used to determine whether to deblock the common edge and to which to apply a deblocking filter, when at least one of the first prediction mode or the second prediction mode comprises SDIP.

6. The method of claim 1 , wherein determining whether to deblock the common edge comprises selecting an adapted set of support to which to apply a deblocking decision function used to determine whether to deblock the edge and to which to apply the deblocking filter, when at least one of the first prediction mode or the second prediction mode comprises SDIP, such that the adapted set of support does not cross prediction unit (PU) boundaries for SDIP PUs in the first block and the second block.

7. The method of claim 1 , wherein the first block and the second block comprise blocks of a frame, the method further comprising:
when at least one of the first prediction mode or the second prediction mode comprises SDIP, storing a value indicative of a partition size for SDIP partitions in a data structure at the location of the data structure corresponding to the common edge; and
deblocking edges based on values stored in the data structure corresponding to the edges.

8. The method of claim 1 , wherein determining the first prediction mode and the second prediction mode comprises selecting, by a video encoder, the first prediction mode and the second prediction mode, the method further comprising, prior to decoding the first block and the second block:
encoding the first block using the first prediction mode; and
encoding the second prediction mode using the second prediction mode,
wherein decoding the first block and the second block comprises decoding, by the video encoder, the first block and the second block.

9. The method of claim 1 , wherein determining the first prediction mode and the second prediction mode comprises receiving, by a video decoder, information indicative of the first prediction mode and the second prediction mode.

10. The method of claim 1 , the method being executable on a wireless communication device, wherein the device comprises:
a memory configured to store the video data;
a processor configured to execute instructions to process the video data stored in the memory; and
a receiver configured to receive a signal including an encoded version of the video data and to store the video data to the memory.

11. The method of claim 10 , wherein the wireless communication device is a cellular telephone and the signal is received by the receiver and modulated according to a cellular communication standard.

12. An apparatus for coding video data, the apparatus comprising:
a memory configured to store video data; and
a video coder configured to:
determine a first prediction mode for a first block of the video data and a second prediction mode for a second block of video data, wherein the first block and the second block share a common edge,
decode the first block using the first prediction mode and the second block using the second prediction mode, and
determine whether to deblock the common edge between the first block and the second block based at least in part on whether at least one of the first prediction mode or the second prediction mode comprises short distance intra-prediction (SDIP), wherein to determine whether to deblock the common edge, the video coder is configured to, when at least one of the first prediction mode and the second prediction mode comprises SDIP:
determine whether SDIP prediction units (PUs) are oriented perpendicular to the common edge;
apply a first deblocking decision function to an equal number of support pixels on either side of the common edge when all of the SDIP PUs are oriented perpendicular to the common edge;
apply a second, different deblocking decision function to an adapted set of support pixels when at least one of the SDIP PUs is oriented parallel to the common edge; and
deblock the common edge when the second deblocking decision function indicates that the common edge is to be deblocked.

13. The apparatus of claim 12 , wherein the video coder is configured to, after determining to deblock the common edge, determine a deblocking filter to deblock the common edge based at least in part on whether at least one of the first prediction mode or the second prediction mode comprises SDIP.

14. The apparatus of claim 13 , wherein to determine the deblocking filter, the video coder is configured to, when at least one of the first prediction mode or the second prediction mode comprises SDIP, determine whether the SDIP PUs are oriented perpendicular to the common edge, and select a deblocking filter having coefficients that can be applied to an equal number of support pixels on either side of the common edge when all of the SDIP PUs are oriented perpendicular to the common edge.

15. The apparatus of claim 12 , wherein the video coder is configured to determine not to deblock the edge when at least one of the first prediction mode or the second prediction mode comprises SDIP.

16. The apparatus of claim 12 , wherein to determine whether to deblock the common edge, the vid

Assignees

• Van Der Auwera Geert
• Karczewicz Marta
• Qualcomm Inc

Inventors

• Van Der Auwera Geert
• Karczewicz Marta

Classifications

• H04N19/117 Primary

  Filters, e.g. for pre-processing or post-processing (sub-band filter banks H04N19/635) · CPC title

• H04N19/176

  the region being a block, e.g. a macroblock · CPC title

• H04N19/82 Primary

  involving filtering within a prediction loop · CPC title

• H04N19/159

  Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction · CPC title

• H04N19/86

  involving reduction of coding artifacts, e.g. of blockiness · CPC title