Deblocking control method considering intra BL mode and multilayer video encoder/decoder using the same

• US 20060146941A1
• Filed: 01/03/2006
• Published: 07/06/2006
• Est. Priority Date: 01/04/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Jae-young, Lee, Kyo-hyuk, Cha, Sang-chang, Han, Woo-jin, Lee, Bae-keun, Ha, Ho-Jin
• Granted Patent: US 8,542,750 B2
• Time in Patent Office: Days
• US Class Current: 375/240.290
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

A deblocking filter used in a video encoder/decoder based on a multilayer is disclosed. The deblocking filtering method includes choosing a present block and its neighboring block on which a deblocking filtering will be performed, judging whether the present block and the neighboring block have been coded by the intra BL mode, choosing a deblocking filter strength according to the result of the judgment, and performing the deblocking filtering with respect to a boundary between the present block and the neighboring block and according to the deblocking filter strength.

Claims

1. A method for deciding a deblocking filter strength for a frame comprising a plurality of blocks, the method comprising:

(a) choosing a present block and a neighboring block on which a deblocking filtering will be performed;

(b) judging whether the present block and the neighboring block have been coded by an intra BL mode; and

(c) deciding the deblocking filter strength according to a result of the judgment.

2. A method for performing a deblocking filtering of a frame comprising a plurality of blocks, the method comprising:

(a) choosing a present block on which a deblocking filtering will be performed and a neighboring block from the plurality of blocks;

(b) judging whether the present block and the neighboring block have been coded by an intra BL mode;

(c) deciding a deblocking filter strength according to a result of the judgment; and

(d) performing the deblocking filtering with respect to a boundary between the present block and the neighboring block according to the deblocking filter strength.

3. The method as claimed in claim 2, wherein (c) comprises:

(c1) if at least one of the present block and the neighboring block is coded by a mode other than the intra BL mode, deciding a specified filter strength with respect to a boundary between the present block and the neighboring block; and

(c2) if both the present block and the neighboring block have been coded by the intra BL mode, deciding a filter strength that is lower than the filter strength decided with respect to the boundary.

4. The method as claimed in claim 3, wherein (c1) further comprises choosing a lower filter strength in a case in which both the present block and the neighboring block are coded by the intra BL mode in comparison to a case in which one of the two blocks is coded by a mode other than the intra BL mode.

5. The method as claimed in claim 2, wherein each block of the plurality of blocks has a size of 4×

4 pixels.

6. The method as claimed in claim 2, wherein the filter strength decided in (c) is divided into filter strengths of different sizes according to whether a block boundary coincides with a macroblock boundary, and if the block boundary coincides with the macroblock boundary, choosing a higher filter strength with respect to the block boundary.

7. The method as claimed in claim 6, wherein if the boundary coincides with the macroblock boundary, the filter strength chosen in (c1) is ‘

4’ and

the filter strength chosen in (c2) is ‘

1’

.

8. The method as claimed in claim 6, wherein if the boundary does not coincide with the macroblock boundary, the filter strength chosen in (c1) is ‘

3’ and

the filter strength chosen in (c2) is ‘

1’

.

9. The method as claimed in claim 2, wherein the boundary is at least one of a horizontal boundary or a vertical boundary between the present block and the neighboring block.

10. A video encoding method based on a multilayer using a deblocking filtering, the method comprising:

(a) encoding an input video frame;

(b) decoding the encoded frame;

(c) deciding a deblocking filter strength according to whether a block included in the decoded frame is coded by an intra BL mode; and

(d) performing the deblocking filtering with respect to a boundary between the block and a neighboring block according to the chosen deblocking filter strength.

11. The video encoding method as claimed in claim 10, wherein (c) comprises:

(c1) choosing a present block on which the deblocking filtering will be performed among a plurality of blocks that constitute the decoded frame and a neighboring block;

(c2) judging whether the present block and the neighboring block have been coded by an intra BL mode; and

(c3) choosing the deblocking filter strength according to a result of the judgment.

12. The video encoding method as claimed in claim 11, wherein a result of performing the deblocking filtering is provided for performing an inter prediction with respect to a subsequent input frame.

13. The video encoding method as claimed in claim 11, wherein the result of performing the deblocking filtering is provided for performing a prediction according to the intra BL mode on an upper layer of a present layer.

14. The video encoding method as claimed in claim 11, wherein (c3) comprises:

(c31) if at least one of the present block and the neighboring block is coded by a mode other than the intra BL mode, choosing a specified filter strength with respect to a boundary between the present block and the neighboring block; and

(c32) if both the present block and the neighboring block are coded by the intra BL mode, choosing a filter strength that is lower than the filter strength decided with respect to the boundary.

15. The method as claimed in claim 14, wherein if the boundary coincides with a macroblock boundary, the filter strength chosen in (c31) is ‘

4’ and

the filter strength chosen in (c32) is ‘

1’

.

16. The method as claimed in claim 14, wherein if the boundary does not coincide with a macroblock boundary, the filter strength chosen in (c31) is ‘

3’ and

the filter strength chosen in (c32) is ‘

1’

.

17. A video decoding method based on a multilayer using deblocking filtering, the method comprising:

(a) restoring a video frame from an input bit stream;

(b) choosing a deblocking filter strength according to whether a block constituting the restored frame has been coded by an intra BL mode; and

(c) performing the deblocking filtering with respect to a boundary between the block and a neighboring block according to the chosen deblocking filter strength.

18. The video decoding method as claimed in claim 17, wherein (b) comprises:

(b1) choosing a present block on which the deblocking filtering will be performed among a plurality of blocks that constitute the decoded frame and a neighboring block;

(b2) judging whether the present block and the neighboring block have been coded by the intra BL mode; and

(b3) choosing the deblocking filter strength according to a result of the judgment.

19. The video decoding method as claimed in claim 18, wherein the result of performing the deblocking filtering is provided for performing motion compensation with respect to a subsequent input frame.

20. The video decoding method as claimed in claim 18, wherein the result of performing the deblocking filtering is provided for restoring a macroblock of an upper layer of a present layer encoded by the intra BL mode.

21. The video decoding method as claimed in claim 18, wherein (b3) comprises:

(b31) if at least one of the present block and the neighboring block has been coded by a mode other than the intra BL mode, choosing a specified filter strength with respect to a boundary between the present block and the neighboring block; and

(b32) if both the present block and the neighboring block have been coded by the intra BL mode, choosing a filter strength that is lower than the filter strength chosen with respect to the boundary.

22. The method as claimed in claim 21, wherein if the boundary coincides with a macroblock boundary, the filter strength chosen in (b31) is ‘

4’ and

the filter strength chosen in (b32) is ‘

1’

.

23. The method as claimed in claim 21, wherein if the boundary does not coincide with a macroblock boundary, the filter strength chosen in (b31) is ‘

3’ and

the filter strength chosen in (b32) is ‘

1’

.

24. A video encoder based on a multilayer using deblocking filtering, the video encoder comprising:

means for encoding an input video frame;

means for decoding the encoded frame;

means for choosing a deblocking filter strength according to whether a block included in the decoded frame has been coded by an intra BL mode; and

means for performing the deblocking filtering with respect to a boundary between the block and a neighboring block according to the chosen deblocking filter strength.

25. A video decoder based on a multilayer using deblocking filtering, the video decoder comprising:

means for restoring a video frame from an input bit stream;

means for deciding a deblocking filter strength according to whether a block included in the restored frame has been coded by an intra BL mode; and

means for performing the deblocking filtering with respect to a boundary between the block and a neighboring block according to the chosen deblocking filter strength.

26. A computer-readable recording medium including program code that can be executed by a computer in order to perform a video encoding method which comprises:

(a) encoding an input video frame;

(b) decoding the encoded frame;

(c) choosing a deblocking filter strength according to whether a block included in the decoded frame has been coded by an intra BL mode; and

(d) performing deblocking filtering with respect to a boundary between the block and a neighboring block according to the chosen deblocking filter strength.

27. The computer-readable recording medium as claimed in claim 26, wherein (c) comprises:

(c1) choosing a present block and a neighboring block on which deblocking filtering will be performed among a plurality of blocks that constitute the decoded frame;

(c2) judging whether the present block and the neighboring block have been coded by the intra BL mode; and

(c3) choosing the deblocking filter strength according to a result of the judgment.

28. A computer-readable recording medium including program code that can be executed by a computer in order to perform a video decoding method which comprises:

(a) restoring a video frame from an input bit stream;

(b) choosing a deblocking filter strength according to whether a block included in the restored frame has been coded by an intra BL mode; and

(c) performing deblocking filtering with respect to a boundary between the block and a neighboring block according to the chosen deblocking filter strength.

29. The computer-readable recording medium as claimed in claim 28, wherein (b) comprises:

(b1) choosing a present block and a neighboring block on which the deblocking filtering will be performed among a plurality of blocks that constitute the decoded frame;

(b2) judging whether the present block and the neighboring block have been coded by the intra BL mode; and

(b3) choosing the deblocking filter strength according to a result of the judgment.