colour.models.log_encoding_AppleLogProfile

colour.models.log_encoding_AppleLogProfile(R: Annotated[_Buffer | _SupportsArray[dtype[Any]] | _NestedSequence[_SupportsArray[dtype[Any]]] | complex | bytes | str | _NestedSequence[complex | bytes | str], 1], constants: Structure | None = None) → Annotated[ndarray[tuple[Any, ...], dtype[float16 | float32 | float64]], 1]

Apply the Apple Log Profile log encoding opto-electronic transfer function (OETF).

Parameters:

• R (Annotated[_Buffer | _SupportsArray[dtype[Any]] | _NestedSequence[_SupportsArray[dtype[Any]]] | complex | bytes | str | _NestedSequence[complex | bytes | str], 1]) – Linear reflection data \(R\).

• constants (Structure | None) – Apple Log Profile constants.

Returns:

Logarithmically encoded value \(P\).

Return type:

numpy.ndarray

References

[AppleInc23], [TheAoMPAaSciences23]

Notes

• The scene reflection signal \(R\) captured by the camera is represented using a floating point encoding. The \(R\) value of 0.18 corresponds to the signal produced by an 18% reflectance reference gray chart.

Domain	Scale - Reference	Scale - 1
R	1	1

Range	Scale - Reference	Scale - 1
P	1	1

Examples

>>> log_encoding_AppleLogProfile(0.18)
0.4882724...