Context model selection based on coding unit characteristics
AssigneeAlibaba Group Holding Limited
InventorsYu-Chen Sun, Jian Lou
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Abstract
Systems and methods are provided for improving accuracy and efficiency of a context-adaptive binary arithmetic coding (CABAC) by adaptively selecting a context model specific to the characteristics of a coding unit (CU), such as the size, dimension (height and/or width), type (luma or chroma), and/or flag type (cu_palette_flag or pred_mode_flag) of the CU, that comprise: determining a characteristic of the CU; determining whether the characteristic of the CU meets a corresponding threshold; and upon determining that the characteristic of the CU meets the corresponding threshold, selecting a first context model, or upon determining that the characteristic of the CU fails to meet the corresponding threshold, selecting a second context model.
Claims19
A method comprising:
- determining a characteristic of a coding unit (CU), the characteristic including a signaling flag associated with the CU, a type of the CU, and a size of the CU;
- selecting a first context model for the coding unit (CU) based at least in part upon:
- determining that the signaling flag associated with the CU is a palette flag,
- determining that the type of the CU is a luma CU, and
- determining that the size of the CU is larger than or equal to a corresponding predefined CU size;
- and
- selecting a second context model for the CU based at least in part upon:
- determining that the signaling flag associated with the CU is the palette flag, and
- determining that the size of the CU is smaller than the corresponding predefined CU size.
A system comprising:
- one or more processors;
- and
- memory communicatively coupled to the one or more processors, the memory storing computer-executable modules executable by the one or more processors that, when executed by the one or more processors, perform associated operations, the computer-executable modules including:
- a characteristic determination module configured to determine a characteristic of a coding unit (CU), the characteristic including a signaling flag associated with the CU, a type of the CU, and a size of the CU;
- a threshold evaluation module configured to evaluate the characteristic of the CU;
- and
- a context model selection module configured to:
- select a first context model based at least in part upon:
- the threshold evaluation module determining that the signaling flag associated with the CU is a palette flag and the size of the CU is larger than or equal to a corresponding predefined CU size, and
- the characteristic determination module determining that the type of the CU is a luma CU, and
- select a second context model based at least in part upon:
- the threshold evaluation module determining that the signaling flag associated with the CU is the palette flag and the size of the CU is smaller than the corresponding predefined CU size.
A non-transitory computer-readable storage medium storing computer-readable instructions executable by one or more processors, that when executed by the one or more processors, cause the one or more processors to perform operations comprising:
- determining a characteristic of the CU, the characteristic including a signaling flag associated with the CU, a type of the CU, and a size of the CU;
- selecting a first context model for the coding unit (CU) based at least in part upon:
- determining that the signaling flag associated with the CU is a palette flag,
- determining that the type of the CU is a luma CU, and
- determining that the size of the CU is larger than or equal to a corresponding predefined CU size;
- and
- selecting a second context model for the CU based at least in part upon:
- determining that the signaling flag associated with the CU is the palette flag, and
- determining that the size of the CU is smaller than the corresponding predefined CU size.
Dependencies are inferred from the claim text.