colour.models.log_decoding_PivotedLog#

colour.models.log_decoding_PivotedLog(y: Annotated[_Buffer | _SupportsArray[dtype[Any]] | _NestedSequence[_SupportsArray[dtype[Any]]] | complex | bytes | str | _NestedSequence[complex | bytes | str], 1], log_reference: float = 445, linear_reference: float = 0.18, negative_gamma: float = 0.6, density_per_code_value: float = 0.002) Annotated[ndarray[tuple[Any, ...], dtype[float16 | float32 | float64]], 1][source]#

Apply the Josh Pines style Pivoted Log log decoding inverse opto-electronic transfer function (OETF).

Parameters:
  • y (Annotated[_Buffer | _SupportsArray[dtype[Any]] | _NestedSequence[_SupportsArray[dtype[Any]]] | complex | bytes | str | _NestedSequence[complex | bytes | str], 1]) – Logarithmically encoded data \(y\).

  • log_reference (float) – Log reference that defines the pivot point in code values where the logarithmic encoding is centred. Typical value is 445.

  • linear_reference (float) – Linear reference that establishes the relationship between linear scene-referred values and the logarithmic code values. Typical value is 0.18, representing 18% grey.

  • negative_gamma (float) – Negative gamma that controls the slope and curvature of the logarithmic portion of the encoding curve. Lower values produce steeper curves with more contrast in the shadows.

  • density_per_code_value (float) – Density per code value that determines the logarithmic step size and affects the overall contrast and dynamic range of the encoded values.

Returns:

Linear data \(x\).

Return type:

numpy.ndarray

Notes

Domain

Scale - Reference

Scale - 1

y

1

1

Range

Scale - Reference

Scale - 1

x

1

1

References

[SonyImageworks12]

Examples

>>> log_decoding_PivotedLog(0.434995112414467)
0.1...