colour.models.eotf_BT2100_HLG#

colour.models.eotf_BT2100_HLG(E_p: FloatingOrArrayLike, L_B: float = 0, L_W: float = 1000, gamma: Optional[float] = None, constants: Structure = CONSTANTS_BT2100_HLG, method: Union[Literal['ITU-R BT.2100-1', 'ITU-R BT.2100-2'], str] = 'ITU-R BT.2100-2') FloatingOrNDArray[source]#

Define Recommendation ITU-R BT.2100 Reference HLG electro-optical transfer function (EOTF).

The EOTF maps the non-linear HLG signal into display light.

Parameters:
  • E_p (FloatingOrArrayLike) – \(E'\) denotes a non-linear colour value \({R', G', B'}\) or \({L', M', S'}\) in HLG space.

  • L_B (float) – \(L_B\) is the display luminance for black in \(cd/m^2\).

  • L_W (float) – \(L_W\) is nominal peak luminance of the display in \(cd/m^2\) for achromatic pixels.

  • gamma (Optional[float]) – System gamma value, 1.2 at the nominal display peak luminance of \(1000 cd/m^2\).

  • constants (Structure) – Recommendation ITU-R BT.2100 Reference HLG constants.

  • method (Union[Literal['ITU-R BT.2100-1', 'ITU-R BT.2100-2'], str]) – Computation method.

Returns:

Luminance \(F_D\) of a displayed linear component \({R_D, G_D, B_D}\) or \(Y_D\) or \(I_D\), in \(cd/m^2\).

Return type:

numpy.floating or numpy.ndarray

Notes

Domain

Scale - Reference

Scale - 1

E_p

[0, 1]

[0, 1]

Range

Scale - Reference

Scale - 1

F_D

[0, 1]

[0, 1]

References

[Bor17], [InternationalTUnion17], [InternationalTUnion18]

Examples

>>> eotf_BT2100_HLG(0.212132034355964)  
6.4760398...
>>> eotf_BT2100_HLG(0.212132034355964, method="ITU-R BT.2100-1")
... 
6.4760398...
>>> eotf_BT2100_HLG(0.212132034355964, 0.01)
... 
7.3321975...