Granted Patent B2

US 12,335,470 · App. 17/650,576 · Granted Jun 17, 2025

Inventors: Mohammed Golam Sarwer (San Mateo, CA); Yan Ye (San Mateo, CA)

Assignee: Alibaba Group Holding Limited

H04N19/117H04N19/176H04N19/196H04N19/436

Abstract

Claims (63)

1. A video decoding method, comprising:

receiving a reconstructed luma block and a first reconstructed chroma block, the reconstructed luma block and the first reconstructed chroma block forming an input to a constraint directional enhancement filter;

determining a direction of the reconstructed luma block;

applying the constraint directional enhancement filter to determine a second reconstructed chroma block based on the first reconstructed chroma block and the direction of the reconstructed luma block;

decoding an encoded bit stream to determine a plurality of filter coefficients associated with a directional cross component filter with a cross shape;

determining an offset by applying the cross-shape directional cross component filter to samples of the reconstructed luma block that are along the determined direction;

adding the offset to the second reconstructed chroma block; and

generating a reconstructed video frame based on the second reconstructed chroma block.

2. The method according to claim 1 , wherein adding the offset to the second reconstructed chroma block comprises:

decoding the encoded bit stream to determine a strength level associated with the offset; and

adding the offset to the second reconstructed chroma block at the strength level.

3. The method according to claim 2 , wherein the strength level is an integer greater than or equal to zero.

4. The method according to claim 2 , wherein an index is signaled in coding parameters to indicate a strength level associated with a filter block.

5. The method according to claim 4 , wherein the filter block is a 64×64 block.

6. The method according to claim 1 , further comprising:

determining, based on a flag, whether the directional cross component filter is enabled for a video sequence or a video frame.

7. The method according to claim 6 , further comprising:

determining the directional cross component filter is enabled, if the flag is signaled in the encoded bit stream and has a first value;

determining the directional cross component filter is disabled, if the flag is signaled in the encoded bit stream and has a second value; and

determining the directional cross component filter is disabled, if the flag is not signaled in the encoded bit stream.

8. The method according to claim 6 , wherein the flag is signaled in a video sequence header or a video frame header.

9. The method according to claim 8 , wherein the flag is signaled in a video frame header if:

a constraint directional enhancement filter is enabled for a video sequence associated with the video frame header, and

the video sequence comprises a chroma component.

10. The method according to claim 1 , wherein the cross-shape directional cross component filter is an 8-tap filter.

11. A video decoding apparatus, comprising:

a memory figured to store instructions; and

one or more processors configured to execute the instructions to cause the apparatus to perform:

receiving a reconstructed luma block and a first reconstructed chroma block, the reconstructed luma block and the first reconstructed chroma block forming an input to a constraint directional enhancement filter;

determining a direction of the reconstructed luma block;

applying the constraint directional enhancement filter to determine a second reconstructed chroma block based on the first reconstructed chroma block and the direction of the reconstructed luma block;

decoding an encoded bit stream to determine a plurality of filter coefficients associated with a directional cross component filter with a cross shape;

determining an offset by applying the cross-shape directional cross component filter to samples of the reconstructed luma block that are along the determined direction;

adding the offset to the second reconstructed chroma block; and

generating a reconstructed video frame based on the second reconstructed chroma block.

12. The video decoding apparatus according to claim 11 , wherein adding the offset to the second reconstructed chroma block comprises:

decoding the encoded bit stream to determine a strength level associated with the offset; and

adding the offset to the second reconstructed chroma block at the strength level.

13. The video decoding apparatus according to claim 12 , wherein the strength level is an integer greater than or equal to zero.

14. The video decoding apparatus according to claim 12 , wherein an index is signaled in coding parameters to indicate a strength level associated with a filter block.

15. The video decoding apparatus according to claim 14 , wherein the filter block is a 64×64 block.

16. The video decoding apparatus according to claim 11 , wherein the one or more processors are configured to execute the instructions to cause the apparatus to perform:

determining, based on a flag, whether the directional cross component filter is enabled for a video sequence or a video frame.

17. The video decoding apparatus according to claim 16 , wherein the one or more processors are configured to execute the instructions to cause the apparatus to perform:

determining the directional cross component filter is enabled, if the flag is signaled in the encoded bit stream and has a first value;

determining the directional cross component filter is disabled, if the flag is signaled in the encoded bit stream and has a second value; and

determining the directional cross component filter is disabled, if the flag is not signaled in the encoded bit stream.

18. The video decoding apparatus according to claim 16 , wherein the flag is signaled in a video sequence header or a video frame header.

19. The video decoding apparatus according to claim 18 , wherein the flag is signaled in a video frame header if:

a constraint directional enhancement filter is enabled for a video sequence associated with the video frame header, and

the video sequence comprises a chroma component.

20. The video decoding apparatus according to claim 11 , wherein the cross-shape directional cross component filter is an 8-tap filter.

21. A method of storing a bitstream of a video, the method comprising:

receiving a reconstructed luma block and a first reconstructed chroma block, the reconstructed luma block and the first reconstructed chroma block forming an input to a constraint directional enhancement filter;

determining a direction of the reconstructed luma block;

applying the constraint directional enhancement filter to determine a second reconstructed chroma block based on the first reconstructed chroma block and the direction of the reconstructed luma block;

determining a plurality of filter coefficients associated with a directional cross component filter with a cross shape;

determining an offset by applying the cross-shape directional cross component filter to samples of the reconstructed luma block that are along the determined direction;

adding the offset to the second reconstructed chroma block;

generating a reconstructed video frame based on the second reconstructed chroma block;

generating a bitstream comprising coded information signaling the plurality of filter coefficients; and

storing the bitstream in a non-transitory computer readable medium.

22. The method according to claim 21 , wherein the cross-shape directional cross component filter is an 8-tap filter.

Assignments (3)

Continuity (2)

References Cited (12)