colour.models.rgb.transfer_functions.bt_2020 Module

ITU-R BT.2020

Defines ITU-R BT.2020 opto-electrical transfer function (OETF / OECF) and electro-optical transfer function (EOTF / EOCF):

See also

RGB Colourspaces Jupyter Notebook

References

[1]International Telecommunication Union. (2015). Recommendation ITU-R BT.2020 - Parameter values for ultra-high definition television systems for production and international programme exchange (Vol. 1). Retrieved from https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.2020-2-201510-I!!PDF-E.pdf
colour.models.rgb.transfer_functions.bt_2020.BT2020_CONSTANTS = {'alpha': <function <lambda>>, 'beta': <function <lambda>>}

BT.2020 colourspace constants.

BT2020_CONSTANTS : Structure

colour.models.rgb.transfer_functions.bt_2020.oetf_BT2020(E, is_12_bits_system=False)[source]

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

Parameters:
  • E (numeric or array_like) – Voltage \(E\) normalized 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) – BT.709 alpha and beta constants are used if system is not 12-bit.
Returns:

Resulting non-linear signal \(E'\).
Return type:

numeric or ndarray

Examples

>>> oetf_BT2020(0.18)  
0.4090077...
colour.models.rgb.transfer_functions.bt_2020.eotf_BT2020(E_p, is_12_bits_system=False)[source]

Defines Recommendation ITU-R BT.2020 electro-optical transfer function (EOTF / EOCF).

Parameters:
  • E_p (numeric or array_like) – Non-linear signal \(E'\).
  • is_12_bits_system (bool) – BT.709 alpha and beta constants are used if system is not 12-bit.
Returns:

Resulting voltage \(E\).
Return type:

numeric or ndarray

Examples

>>> eotf_BT2020(0.705515089922121)  
0.4999999...