CN-121986488-A - Filtering applied to chroma direct block vectors

Abstract

A template-based filter can be used to refine predictions obtained based on chroma Direct Block Vectors (DBVs). The video decoding/encoding apparatus can include a processor. The apparatus can be configured to obtain a prediction of a chroma block based on a chroma direct block vector. The apparatus is capable of refining the prediction based on a template of the chroma direct block vector and/or a template of the prediction. The apparatus is capable of decoding/encoding the chroma block based on the refined prediction. The apparatus can determine whether to refine the prediction based on a Local Illumination Compensation (LIC) indication or a linear filter model (FLM) indication associated with the chroma block. The prediction can be refined based on the LIC indication indicating that the LIC is in an active state and/or the FLM indication indicating that the FLM is in an active state for the chroma block.

Inventors

• F. Leriennik
• K. Nasser
• CHEN YA
• Milos Radosavlevich

Assignees

• 交互数字CE专利控股有限公司

Dates

Publication Date

20260505

Application Date

20240923

Priority Date

20231002

Claims (20)

1. 1. A video decoding apparatus, the video decoding apparatus comprising: the processor may be configured to perform the steps of, the processor is configured to: obtaining a prediction of a chroma block based on the chroma direct block vector; refining the prediction based on a template of the chroma direct block vector and a template of the prediction, and The chroma block is decoded based on the refined prediction.
2. 2. A video encoding apparatus, the video encoding apparatus comprising: the processor may be configured to perform the steps of, the processor is configured to: obtaining a prediction of a chroma block based on the chroma direct block vector; refining the prediction based on a template of the chroma direct block vector and a template of the prediction, and The chroma block is encoded based on the refined prediction.
3. 3. The device of any of claims 1 or 2, wherein the processor is further configured to: Determining whether to refine the prediction based on a Local Illumination Compensation (LIC) indication or a linear filter model (FLM) indication associated with the chroma block, wherein the prediction is refined based on the LIC indication indicating that the LIC is in an active state or the FLM indication indicating that the FLM is in an active state for the chroma block.
4. 4. The device of any of claims 1-3, wherein the processor is further configured to: Determining LIC parameters based on templates of the chroma blocks and templates of reference blocks under the condition that the LIC indication indicates that LIC is in an active state for the chroma blocks, and The prediction is further refined based at least on the LIC parameters.
5. 5. The device of any of claims 1-4, wherein the processor is further configured to: Determining FLM filter parameters based on a template of the chroma block and the predicted template under a condition that the FLM indication indicates that the FLM is in an active state for the chroma block, and The prediction is further refined based on the FLM filter parameters.
6. 6. The device of any of claims 1 or 2, wherein the processor is further configured to: a determination is made as to whether to update the prediction based on LIC or FLM usage associated with a luma block located with the chroma block.
7. 7. The device of claim 6, wherein the processor is further configured to: Determining LIC parameters based on templates of the chroma blocks under the condition that LIC is being used for the luma blocks located with the chroma blocks, and The prediction is further updated based on the LIC parameters.
8. 8. The device of any of claims 6 or 7, wherein the processor is further configured to: Determining FLM filter parameters based on a template of the chroma block under the condition that FLM is being used for the luma block located with the chroma block, and The prediction is further updated based on the FLM filter parameters.
9. 9. The device of claims 1 and 3, 4 or 5, wherein the processor is further configured to receive the LIC indication or the FLM indication in video data.
10. 10. The device of claims 2 and 3, 4 or 5, wherein the processor is further configured to send the LIC indicator or the FLM indication in video data.
11. 11. The device of any of claims 3 to 10, wherein the processor is further configured to derive the LIC indication from a luma block associated with the chroma block.
12. 12. A video decoding method, the video decoding method comprising: obtaining a prediction of a chroma block based on the chroma direct block vector; refining the prediction based on a template of the chroma direct block vector and a template of the prediction, and The chroma block is decoded based on the refined prediction.
13. 13. A video encoding method, the video encoding method comprising: obtaining a prediction of a chroma block based on the chroma direct block vector; refining the prediction based on a template of the chroma direct block vector and a template of the prediction, and The chroma block is encoded based on the refined prediction.
14. 14. The method of any one of claims 12 or 13, wherein the method further comprises: Determining whether to refine the prediction based on a Local Illumination Compensation (LIC) indication or a linear filter model (FLM) indication associated with the chroma block, wherein the prediction is refined based on the LIC indication indicating that the LIC is in an active state or the FLM indication indicating that the FLM is in an active state for the chroma block.
15. 15. The method of claim 14, wherein the method further comprises: Determining LIC parameters based on templates of the chroma blocks and templates of reference blocks under the condition that the LIC indication indicates that LIC is in an active state for the chroma blocks, and The prediction is further refined based at least on the LIC parameters.
16. 16. The method of any one of claims 14 or 15, wherein the method further comprises: Determining FLM filter parameters based on a template of the chroma block and the predicted template under a condition that the FLM indication indicates that the FLM is in an active state for the chroma block, and The prediction is further refined based on the FLM filter parameters.
17. 17. The method of any one of claims 12 or 13, wherein the method further comprises: a determination is made as to whether to update the prediction based on LIC or FLM usage associated with a luma block located with the chroma block.
18. 18. The method of claim 17, wherein the method further comprises: Determining LIC parameters based on templates of the chroma blocks under the condition that LIC is being used for the luma blocks located with the chroma blocks, and The prediction is further updated based on the LIC parameters.
19. 19. The method of any one of claims 17 or 18, wherein the method further comprises: Determining FLM filter parameters based on a template of the chroma block under the condition that FLM is being used for the luma block located with the chroma block, and The prediction is further updated based on the FLM filter parameters.
20. 20. The method of claim 12 and 14, 15 or 16, wherein the method further comprises receiving the LIC indication or the FLM indication in video data.

Description

Filtering applied to chroma direct block vectors Cross Reference to Related Applications The present application claims the benefit of european provisional patent application No. 23306656.2 filed on day 2 of 10 in 2023 and european provisional patent application No. 23306687.7 filed on day 2 of 10 in 2023, the contents of which are incorporated herein by reference. Background Video coding systems may be used to compress digital video signals, for example, to reduce the storage and/or transmission bandwidth required for such signals. Video coding systems may include, for example, block-based, wavelet-based, and/or object-based systems. Disclosure of Invention Systems, methods, and tools for applying filtering to direct block vectors are disclosed. A video decoding/encoding device may include a processor. The apparatus may be configured to obtain a prediction of a chroma block based on the chroma direct block vector. The device may refine the prediction based on a template of the chroma direct block vector and/or a template of the prediction. The device may decode/encode the chroma block based on the refined prediction. The device may include one or more of the following features. The device may determine whether to refine the prediction based on a Local Illumination Compensation (LIC) indication or a linear filter model (FLM) indication associated with the chroma block. The prediction may be refined based on an LIC indication indicating that the LIC is active for the chroma block. The prediction may be refined based on the FLM indication indicating that the FLM is active for the chroma block. Based on the LIC indication indicating a condition that the LIC is in an active state for the chroma block, the device may determine the LIC parameters based on a template of the chroma block and a template of the reference block. The device may further refine the prediction based at least on the LIC parameters. Based on the FLM indication indicating a condition that the FLM is in an active state for the chroma block, the device may determine FLM filter parameters based on a template of the chroma block and a predicted template. The device may further refine the prediction based on FLM filter parameters. The device may determine whether to update the prediction based on LIC usage associated with a luma block located with the chroma block or based on FLM usage. Based on the conditions under which the LIC is being used for the luma block located with the chroma block, the device may determine the LIC parameters based on a template of the chroma block. The device may further update the predictions based on the LIC parameters. Based on the conditions under which the FLM is being used for a luma block that is located with a chroma block, the device may determine FLM filter parameters based on a template for the chroma block. The device may further update the prediction based on the FLM filter parameters. The device may receive an LIC indication or an FLM indication in the video data. The device may send an LIC indicator or FLM indication in the video data. The device may derive the LIC indication from a chroma block associated with the chroma block. Systems, methods, and tools for refining predictions obtained based on chroma Direct Block Vectors (DBVs) using template-based filters are disclosed. For example, local Illumination Compensation (LIC) may be performed to refine the prediction of chroma blocks encoded in DBV mode. For example, a Filter Linear Model (FLM) may be used to refine the prediction of chroma blocks encoded in DBV mode. A video decoding apparatus may obtain a prediction of a chroma block based on a chroma direct block vector and refine the prediction based on a template of the chroma block and a template of the prediction. For example, LIC parameters may be derived based on a template of chroma blocks and a predicted template. The predictions may be refined based on the derived LIC parameters. For example, the FLM may be derived based on a template of the chroma block and a predicted template. The predictions may be refined based on the derived FLM. The video decoding apparatus may decode the chroma block based on the refined prediction. For example, the refined prediction may be combined with the residual of the chroma block to reconstruct the chroma block. The video decoding device may determine whether to refine the prediction of the chroma block based on the indication in the video data. For example, an encoded block level indication (such as a local illumination indication) may be configured to indicate whether local illumination compensation is to be performed on the chroma block. For example, an encoded block level indication (such as an FLM indication) may be configured to indicate whether an FLM model is to be applied to a chroma block. The video decoding apparatus may determine whether to refine the prediction of the chroma block based on the use of refinement in the co-located luma block. For ex