The cieuv2cct function calculates the Correlated Colour Temperature (CCT) T_{\mathrm{cp}} from given CIE 1960 chromaticity coordinates u and v, also known as Uniform Colour Space (UCS). See also: ciexy2cct. 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:
Tcp = cieuv2cct(u,v,'method')
Where:
| Parameter | Description |
Tcp | Is a scalar or vector containing the resulting Correlated Colour Temperature(s) (CCT) in K. |
u and v | Are the input scalars or vectors containing the CIE 1960 chromaticity coordinates u and v. |
'method' | Specifies the determination method: ‘Robertson’: (default) Robertson’s calculation algorithm, formerly the only recommended algorithm by the CIE. This method is fast and quite accurate. ‘exact’: shortest distance method as described in CIE 15:2018, very accurate but comparably slow. Results may vary with different implementation methods. Both methods return NaN if the colour coordinates lie outside the meaningful interval of \Delta uv < 0.05 from the planckian locus in CIE 1960 chromaticity diagram. |
Examples
Correlated Colour Temperature T_{\mathrm{cp}} for u = 0.2308 and y = 0.2825 using the default ‘Robertson’ method:
u = 0.2308; v = 0.2825; Tcp = cieuv2cct(u,v)
Result:
Tcp = 7513
Correlated Colour Temperature T_{\mathrm{cp}} forr u = 0.2308 and y = 0.2825 using ‘exact’ method:
u = 0.2308; v = 0.2825; Tcp = cieuv2cct(u,v,'exact')
Result:
Tcp = 7519.3
Correlated Colour Temperature T_{\mathrm{cp}} for several chromaticity coordinates using ‘Robertson’ method:
u = linspace(0.25,0.30,5) v = linspace(0.25,0.30,5) Tcp = cieuv2cct(u,v,'Robertson')
Result:
u = 0.2500 0.2625 0.2750 0.2875 0.3000 v = 0.2500 0.2625 0.2750 0.2875 0.3000 Tcp = 50060 7679 3202 2498 2169
References