colour.models.eotf_HLG_BT2100

colour.models.eotf_HLG_BT2100(E_p, L_B=0, L_W=1000, gamma=None, constants={'a': 0.17883277, 'b': 0.28466892, 'c': 0.559910729529562}, method='ITU-R BT.2100-2')[source]

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

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

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

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

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

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

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

  • method (str, optional) – {‘ITU-R BT.2100-1’, ‘ITU-R BT.2100-2’}, 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

numeric or 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_HLG_BT2100(0.212132034355964)  
6.4760398...
>>> eotf_HLG_BT2100(0.212132034355964, method='ITU-R BT.2100-1')
... 
6.4760398...
>>> eotf_HLG_BT2100(0.212132034355964, 0.01)
... 
7.3321975...