colour.colorimetry.illuminants Module¶
Illuminants¶
Defines CIE illuminants computation related objects:
See also
Illuminants IPython Notebook colour.colorimetry.dataset.illuminants.d_illuminants_s_spds, colour.colorimetry.spectrum.SpectralPowerDistribution
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colour.colorimetry.illuminants.
D_illuminant_relative_spd
(xy)[source]¶ Returns the relative spectral power distribution of given CIE Standard Illuminant D Series using given xy chromaticity coordinates.
References
[1] Wyszecki, G., & Stiles, W. S. (2000). CIE Method of Calculating D-Illuminants. In Color Science: Concepts and Methods, Quantitative Data and Formulae (pp. 145–146). Wiley. ISBN:978-0471399186 [2] Lindbloom, B. (2007). Spectral Power Distribution of a CIE D-Illuminant. Retrieved April 05, 2014, from http://www.brucelindbloom.com/Eqn_DIlluminant.html Parameters: xy (array_like) – xy chromaticity coordinates. Returns: CIE Standard Illuminant D Series relative spectral power distribution. Return type: SpectralPowerDistribution Examples
>>> xy = np.array([0.34570, 0.35850]) >>> print(D_illuminant_relative_spd(xy)) SpectralPowerDistribution('CIE Standard Illuminant D Series', (300.0, 830.0, 10.0))
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colour.colorimetry.illuminants.
CIE_standard_illuminant_A_function
(wl)[source]¶ CIE Standard Illuminant A is intended to represent typical, domestic, tungsten-filament lighting. Its relative spectral power distribution is that of a Planckian radiator at a temperature of approximately 2856 K. CIE Standard Illuminant A should be used in all applications of colorimetry involving the use of incandescent lighting, unless there are specific reasons for using a different illuminant.
Parameters: wl (array_like) – Wavelength to evaluate the function at. Returns: CIE Standard Illuminant A value at given wavelength. Return type: ndarray References
[1] CIE TC 1-48. (2004). 3.1 Recommendations concerning standard physical data of illuminants. In CIE 015:2004 Colorimetry, 3rd Edition (pp. 12–13). ISBN:978-3-901-90633-6 Examples
>>> wl = np.array([560, 580, 581.5]) >>> CIE_standard_illuminant_A_function(wl) array([ 100. , 114.4363383..., 115.5285063...])