colour_hdri.average_luminance¶

colour_hdri.average_luminance(f_number, exposure_time, iso, k=12.5)[source]¶

Computes the average luminance in \(cd\cdot m^{-2}\) from given image F-Number \(N\), Exposure Time \(t\), ISO speed \(S\) and reflected light calibration constant \(k\).

Parameters:	f_number (array_like) – Image F-Number \(N\). exposure_time (array_like) – Image Exposure Time \(t\). iso (array_like) – Image ISO \(S\). k (numeric, optional) – Reflected light calibration constant \(k\).
Returns:	Image average luminance in \(cd\cdot m^{-2}\).
Return type:	ndarray

References

[Wika]

Examples

>>> average_luminance(8, 1, 100)
8.0