colour.models.rgb.transfer_functions.bt_709 Module¶

ITU-R BT.709-6¶

Defines ITU-R BT.709-6 opto-electrical transfer function (OETF / OECF) and electro-optical transfer function (EOTF / EOCF):

oetf_BT709()
eotf_BT709()

See also

RGB Colourspaces Jupyter Notebook

References

[1]

International Telecommunication Union. (2015). Recommendation ITU-R BT.709-6 - Parameter values for the HDTV standards for production and international programme exchange BT Series Broadcasting service (Vol. 5). Retrieved from https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.709-6-201506-I!!PDF-E.pdf

colour.models.rgb.transfer_functions.bt_709.oetf_BT709(L)[source]¶

Defines Recommendation ITU-R BT.709-6 opto-electronic transfer function (OETF / OECF).

Parameters:	L (numeric or array_like) – Luminance \(L\) of the image.
Returns:	Corresponding electrical signal \(V\).
Return type:	numeric or ndarray

Examples

>>> oetf_BT709(0.18)  
0.4090077...

colour.models.rgb.transfer_functions.bt_709.eotf_BT709(V)[source]¶

Defines Recommendation ITU-R BT.709-6 electro-optical transfer function (EOTF / EOCF).

Parameters:	V (numeric or array_like) – Electrical signal \(V\).
Returns:	Corresponding luminance \(L\) of the image.
Return type:	numeric or ndarray

Warning

Recommendation ITU-R BT.709-6 doesn’t specify an electro-optical transfer function. This definition is used for symmetry in unit tests and other computations but should not be used as an EOTF.

Examples

>>> eotf_BT709(0.409007728864150)  
0.1...