Mode dependent intra smoothing filter table mapping methods for non-square prediction units

Patent metadata

Field	Value
Publication number	US-10015522-B2
Application number	US-201715432555-A
Country	US
Kind code	B2
Filing date	Feb 14, 2017
Priority date	Jun 15, 2011
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

An apparatus including a memory operably coupled to a processor. The processor is configured to determine whether to use an intra smoothing filter for a rectangular prediction unit (PU) based on a lookup table (LUT) used for square PUs, wherein a width of the rectangular PU is not equal to a height of the rectangular PU.

First claim

What is claimed is:

1. An apparatus comprising:
a memory; and
a processor operably coupled to the memory and configured to:

determine whether to use an intra smoothing filter for a rectangular prediction unit (PU) based on a lookup table (LUT) used for square PUs,
wherein a width of the rectangular PU is not equal to a height of the rectangular PU.

2. The apparatus of claim 1 , wherein the processor is further configured to determine an intra prediction mode for the rectangular PU, wherein the LUT for a square PU is indexed by an intra prediction mode and a width of the square PU, and wherein an entry of the LUT is selected for the rectangular PU corresponding to square PUs with the same intra prediction mode and width as for the rectangular PU.

3. The apparatus of claim 2 , wherein no intra smoothing filter is used when the width of the rectangular PU is equal to one.

4. The apparatus of claim 3 , wherein no intra smoothing filter is used when the height of the rectangular PU is equal to one.

5. The apparatus of claim 2 , wherein no intra smoothing filter is used when the width of the rectangular PU is less than five.

6. The apparatus of claim 5 , wherein no intra smoothing filter is used when the height of the rectangular PU is less than five.

7. The apparatus of claim 1 , wherein the processor is further configured to determine an intra prediction mode for the rectangular PU, wherein the LUT for a square PU is indexed by an intra prediction mode and height of the square PU, and wherein an entry of the LUT is selected for the rectangular PU corresponding to square PUs with the same intra prediction mode and height as for the rectangular PU.

8. The apparatus of claim 7 , wherein no intra smoothing filter is used when the height of the rectangular PU is equal to one.

9. The apparatus of claim 8 , wherein no intra smoothing filter is used when the width of the rectangular PU is equal to one.

10. The apparatus of claim 7 , wherein no intra smoothing filter is used when the height of the rectangular PU is less than five.

11. The apparatus of claim 10 , wherein no intra smoothing filter is used when the width of the rectangular PU is less than five.

12. The apparatus of claim 1 , wherein the processor is further configured to determine an intra prediction mode for the rectangular PU, wherein the LUT for a square PU is indexed by an intra prediction mode and a dimension of the square PU, wherein an entry of the LUT is selected for the rectangular PU corresponding to square PUs, wherein the corresponding rectangular PU has the same intra prediction mode as for the square PUs, and wherein the greater value between the width and height of the corresponding rectangular PU is equal to a width of the square PUs.

13. The apparatus of claim 1 , wherein the processor is further configured to determine an intra prediction mode for the rectangular PU, wherein the LUT for a square PU is indexed by an intra prediction mode and a block-size of the square PU, and wherein an entry of the LUT is selected for the rectangular PU corresponding to square PUs with the same intra prediction mode and block-size as for the rectangular PU.

14. The apparatus of claim 13 , wherein no intra smoothing filter is used when the width or height of the rectangular PU is equal to one.

15. The apparatus of claim 13 , wherein no intra smoothing filter is used when the width or height of the rectangular PU is less than five.

16. The apparatus of claim 1 , wherein the processor is further configured to determine a type of the intra smoothing filter for the rectangular PU based on the LUT used for square PUs.

17. A method implemented by a processor at least partially implemented in hardware, comprising:
determining, by the processor, whether to use an intra smoothing filter for a rectangular prediction unit (PU) based on a lookup table (LUT) used for square PUs, wherein a width of the rectangular PU is not equal to a height of the rectangular PU; and
using the intra smoothing filter to code video content.

18. The method of claim 17 , further comprising determining an intra prediction mode for the rectangular PU, wherein the LUT for a square PU is indexed by an intra prediction mode and a width of the square PU, and wherein an entry of the LUT is selected for the rectangular PU corresponding to square PUs with the same intra prediction mode and width as for the rectangular PU.

19. The method of claim 17 , further comprising determining an intra prediction mode for the rectangular PU, wherein the LUT for a square PU is indexed by an intra prediction mode and a height of the square PU, and wherein an entry of the LUT is selected for the rectangular PU corresponding to square PUs with the same intra prediction mode and height as for the rectangular PU.

20. The method of claim 17 , further comprising determining an intra prediction mode for the rectangular PU, wherein the LUT for a square PU is indexed by an intra prediction mode and a block-size of the square PU, and wherein an entry of the LUT is selected for the rectangular PU corresponding to square PUs with the same intra prediction mode and block-size as for the rectangular PU.

21. An apparatus comprising:
a memory; and
a processor operably coupled to the memory and configured to:

divide a square coding unit (CU) into a plurality of blocks including a rectangular prediction unit (PU) according to a Short Distance Intra Prediction (SDIP) scheme, wherein the width of the rectangular PU is not equal to the height of the rectangular PU; and
determine whether to use an intra smoothing filter for the rectangular PU based on a lookup table (LUT) used in Mode Dependent Intra Smoothing (MDIS) for square PUs.

22. The apparatus of claim 21 , wherein the LUT for a square PU is indexed by an intra prediction mode and a dimension of the square PU, and wherein the processor is further configured to select an intra prediction mode for the rectangular PU according to the SDIP scheme.

23. The apparatus of claim 22 , wherein an entry of the LUT is selected for the rectangular PU corresponding to square PUs with the same intra prediction mode and width as for the rectangular PU.

24. The apparatus of claim 22 , wherein an entry of the LUT is selected for the rectangular PU corresponding to square PUs with the same intra prediction mode and height as for the rectangular PU.

25. The apparatus of claim 22 , wherein an entry of the LUT is selected for the rectangular PU corresponding to square PUs with the same intra prediction mode and block-size as for the rectangular PU.

Assignees

• Futurewei Technologies Inc

Inventors

• Li Guichun
• Liu Lingzhi
• Lai Changcai
• Ling Nam
• Zheng Jianhua
• Zhang Chen-Xiong

Classifications

• H04N19/86 Primary

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

• H04N19/117

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

• H04N19/11

  among a plurality of spatial predictive coding modes · CPC title

• H04N19/176

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

• H04N19/159

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