colour.models.oetf_BT2020

colour.models.oetf_BT2020(E, is_12_bits_system=False, constants={'alpha': <function <lambda>>, 'beta': <function <lambda>>})[source]

Defines Recommendation ITU-R BT.2020 opto-electrical transfer function (OETF / OECF).

Parameters:
  • E (numeric or array_like) – Voltage \(E\) normalised by the reference white level and proportional to the implicit light intensity that would be detected with a reference camera colour channel R, G, B.
  • is_12_bits_system (bool, optional) – BT.709 alpha and beta constants are used if system is not 12-bit.
  • constants (Structure, optional) – Recommendation ITU-R BT.2020 constants.
Returns:

Resulting non-linear signal \(E'\).

Return type:

numeric or ndarray

Notes

Domain Scale - Reference Scale - 1
E [0, 1] [0, 1]
Range Scale - Reference Scale - 1
E_p [0, 1] [0, 1]

References

[InternationalTelecommunicationUnion2015h]

Examples

>>> oetf_BT2020(0.18)  # doctest: +ELLIPSIS
0.4090077...