frudawski

ciespec

The ciespec function contains various reference spectra provided by the Commission International d’Éclairage (CIE – International Commission on Illumination). The reference data is sourced from the CIE and permission to use the data in the Lighting Toolbox was granted. Any errors in the data set or in results generated with the Lighting Toolbox are not in the liability of the CIE nor me, see licence.

Usage:

spec = ciespec(lam,'ref',Y,W)

Where:

ParameterDescription
specIs the return vector or matrix containing the reference spectrum/spectra.
lamIs a vector defining the wavelengths. For wavelength steps smaller than given in the reference, the function does a linear interpolation, as suggested by the CIE.
'ref'Defines the reference spectrum/spectra, see table below.
Y
(optional)
Defines the integral weighted target value derived from the spectral power distribution.
W
(optional)
Defines the weighting function for the integral target value (see above). Default: 'VL' for the V(\lambda) weighted photopic value.

For wavelength increments smaller than given in the reference, the function does a linear interpolation, as suggested by the CIE. It is also possible to assign multiple references in one function call by using a cell array:

spec = ciespec(lambda,{'ref1','ref2',...,'refx'})

Note: the spectra are returned row wise as a n \times m matrix, with n spectra and m wavelength steps.

Sensitivity functions references:

ReferenceDescription
'x'2° tristimulus function \bar{x}
'y'2° tristimulus function \bar{y}, equals ’VL’
'z'2° tristimulus function \bar{z}
'xyz'2° tristimulus functions \bar{x}, \bar{y} and \bar{z}
'x10'10° tristimulus function \bar{x}_{10}
'y10'10° tristimulus function \bar{y}_{10}
'z10'10° tristimulus function \bar{z}_{10}
'xyz10'10° tristimulus function \bar{x}_{10}, \bar{y}_{10} and \bar{z}_{10}
'r'CIE \bar{r} function, note: source only 380 nm – 780 nm in 5 nm steps
'g'CIE \bar{g} function, note: source only 380 nm – 780 nm in 5 nm steps
'b'CIE \bar{b} function, note: source only 380 nm – 780 nm in 5 nm steps
'rgb'CIE \bar{r}, \bar{g} and \bar{b} function, note: source only 380 nm – 780 nm in 5 nm steps
'VL'V(\lambda), equals tristimulus function ’y’
'V-L'V'(\lambda), equals rhodopic/scotopic ’rh’
'sc'retinal ganglion cells: s-cone-opic s_{\text{sc}} or cyanopic
'mc'retinal ganglion cells: m-cone-opic s_{\text{mc}} or chloropic
'lc'retinal ganglion cells: l-cone-opic s_{\text{lc}} or erythropic
'rh'retinal ganglion cells: rhodopic s_{\text{rh}}, or scotopic, equals ’V-L’
'mel'retinal ganglion cells: melanopic s_{\text{mel}}
'a-opic'all retinal ganglion cells: s_{\text{sc}}, s_{\text{mc}}, s_{\text{lc}}, s_{\text{rh}} and s_{\text{mel}}
'BLH'Blue Light Hazard weighting function

Standard illuminant references:

ReferenceDescription
'A'standard illuminant A
'C'former standard illuminant
'D65'standard illuminant daylight 6500 K
'D50'illuminant daylight 5000 K – D65 recommended
'D55'illuminant daylight 5500 K – D65 recommended
'D75'illuminant daylight 7500 K – D65 recommended
'DXX'daylight XX00 K – not CIE standard
'DXXXX'daylight XXXX K – not CIE standard
'E'equi-energy illuminant
'FL1'standard illuminant FL1: standard flourescent lamp
'FL2'standard illuminant FL2: standard flourescent lamp – recommended
'FL3'standard illuminant FL3: standard flourescent lamp
'FL4'standard illuminant FL4: standard flourescent lamp
'FL5'standard illuminant FL5: standard flourescent lamp
'FL6'standard illuminant FL6: standard flourescent lamp
'FL7'standard illuminant FL7: broadband flourescent lamp – recommended
'FL8'standard illuminant FL8: broadband flourescent lamp
'FL9'standard illuminant FL9: broadband flourescent lamp
'FL10'standard illuminant FL10: narrow band flourescent lamp
'FL11'standard illuminant FL11: narrow band flourescent lamp – recommended
'FL12'standard illuminant FL12: narrow band flourescent lamp
'FL3.1'standard illuminant FL3.1: standard halophosphat lamp
'FL3.2'standard illuminant FL3.2: standard halophosphat lamp
'FL3.3'standard illuminant FL3.3: standard halophosphat lamp
'FL3.4'standard illuminant FL3.4: DeLuxe type lamp
'FL3.5'standard illuminant FL3.5: DeLuxe type lamp
'FL3.6'standard illuminant FL3.6: DeLuxe type lamp
'FL3.7'standard illuminant FL3.7: three band fluorescent lamp
'FL3.8'standard illuminant FL3.8: three band fluorescent lamp
'FL3.9'standard illuminant FL3.9: three band fluorescent lamp
'FL3.10'standard illuminant FL3.10: three band fluorescent lamp
'FL3.11'standard illuminant FL3.11: three band fluorescent lamp
'FL3.12'standard illuminant FL3.12: multi band fluorescent lamp
'FL3.13'standard illuminant FL3.13: multi band fluorescent lamp
'FL3.14'standard illuminant FL3.14: multi band fluorescent lamp
'FL3.15'standard illuminant FL3.15: D65 simulator lamp
'HP1'standard illuminant HP1: standard high pressure sodium lamp
'HP2'standard illuminant HP2: colour enhanced high pressure sodium lamp
'HP3'standard illuminant HP3: standard high pressure metal halide lamp
'HP4'standard illuminant HP4: standard high pressure metal halide lamp
'HP5'standard illuminant HP5: standard high pressure metal halide lamp
'LED-B1'standard illuminant Phosphor-type LED
'LED-B2'standard illuminant Phosphor-type LED
'LED-B3'standard illuminant Phosphor-type LED
'LED-B4'standard illuminant Phosphor-type LED
'LED-B5'standard illuminantPhosphor-type LED
'LED-BH1'standard illuminant Hybrid-type LED
'LED-RGB1'standard illuminant RGB-type LED
'LED-V1'standard illuminant violet pumped phosphor-type LED
'LED-V2'standard illuminant violet pumped phosphor-type LED

Other references:

ReferenceDescription
'W'spectral window transmitance for indoor daylight illuminant
'CRI'coulor rendering index reference data (14 probes)
'CFI'colour fidelity index reference data (99 probes)

Examples:

Plot Tristimulus functions \bar{x}, \bar{y} and \bar{z}:

lam = 380:780;
ref = ciespec(lam,'xyz');
plot(lam,ref)

Result:

Plot D65 spectrum:

lam = 360:830;
spec = ciespec(lam,'D65');
plotspec(lam,spec)

See also: plotspec

Note: plotspec plots only in the visible region from 380 nm to 780 nm.

Result:

Plot \mathbf{\alpha}-opic functions in shades of gray:

lam = 380:780;
ref = ciespec(lam,'a-opic');
c = colors(5,'S',zeros(5,1));
plotorder(lam,ref,c)
xlim([380 780])
legend('s_{sc}','s_{mc}','s_{lc}','s_{rh}','s_{mel}')
xlabel('\lambda in nm')
grid on

see also: colors, plotorder

Result:

Plot CIE Colour Rendering Index (CRI) reference colours:

lam = 380:780;
spec = ciespec(lam,'CRI');
c = spec2srgb(lam,spec);
plotcolour(c)

See also: spec2srgb, plotcolour

Result:

Create spectral power distribution of standard illuminants ‘FL4’ and ‘FL8’ with resulting photometric value of |Y| = 10000:

lam = 380:780;
spec = ciespec(lam,{'FL4','FL8'},10000);
Y = ciespec2Y(lam,spec) 

See also: ciespec2Y

Result:

Y =

   1.0000e+04
   1.0000e+04

Create spectral power distribution of standard illuminants ‘FL4’ and ‘FL8’ with different weighting functions and target values:

lam = 380:780;
spec = ciespec(lam,{'FL4','FL8'},[100 200],{'VL','mel'});
Y = ciespec2Y(lam,spec)
mel = ciespec2unit(lam,spec,'mel')

See also: ciespec2Y, ciespec2unit

Result:

Y =

   1.0000e+02
   1.8729e+05

mel =

   4.1844e-02
   2.0000e+02

References

ISO/CIE 11664-1:2019(E): Colorimetry - Part 1: CIE standard colorimetric observers. Commission International de l’Éclairage (CIE), Vienna Austria, 2019.

ISO/CIE 11664-2:2022(E): Colorimetry - Part 2: CIE standard illuminants. Commission International de l’Éclairage (CIE), Vienna Austria, 2022.

CIE 15:2018: Colorimetry, 4th Edition. Commission International de l’Éclairage (CIE), Vienna Austria, 2018, ISBN: 978-3-902842-13-8 , (DOI: 10.25039/TR.015.2018).

CIE S 026/E:2018: CIE System for Metrology of Optical Radiation for ipRGC-Influenced Responses to Light. Commission International de l’Éclairage (CIE), Vienna Austria, 2018, (DOI: 10.25039/S026.2018).

IEC 62471:2006/CIE S 009:2002: Photobiological safety of lamps and lamp systems / Sécurité photobiologique des lampes et des appareils utilisant des lampes (bilingual edition). Commission Internationale de l'Éclairage (CIE), Vienna Austria, 2002.

CIE 224:2017: CIE 2017 Colour Fidelity Index for accurate scientific use. Commission International de l’Éclairage (CIE), Vienna Austria, 2017, ISBN: 978-3-902842-61-9.

CIE 13.3:1995: Method of measuring and specifying colour rendering properties of light sources. Commission Internationale de l'Éclairage (CIE), Vienna Austria, 1995, ISBN: 978 3 900734 57 2.

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