Defines correlated colour temperature Tcp computations objects:
References
[1] | Wikipedia. (n.d.). Color temperature. Retrieved June 28, 2014, from http://en.wikipedia.org/wiki/Color_temperature |
alias of PlanckianTable_Tuvdi
Robertson (1968) iso-temperature lines.
Notes
References
[2] | Wyszecki, G., & Stiles, W. S. (2000). Table 1(3.11) Isotemperature Lines. In Color Science: Concepts and Methods, Quantitative Data and Formulae (p. 228). Wiley. ISBN:978-0471399186 |
alias of WyszeckiRobertson_ruvt
Returns a planckian table from given CIE UCS colourspace uv chromaticity coordinates, colour matching functions and temperature range using Ohno (2013) method.
Parameters: |
|
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Returns: | Planckian table. |
Return type: | list |
Examples
>>> from colour import STANDARD_OBSERVERS_CMFS
>>> from pprint import pprint
>>> cmfs = 'CIE 1931 2 Degree Standard Observer'
>>> cmfs = STANDARD_OBSERVERS_CMFS.get(cmfs)
>>> pprint(planckian_table((0.1978, 0.3122), cmfs, 1000, 1010, 10))
[PlanckianTable_Tuvdi(Ti=1000.0, ui=0.4480108..., vi=0.3546249..., di=0.2537821...),
PlanckianTable_Tuvdi(Ti=1001.1111111..., ui=0.4477508..., vi=0.3546475..., di=0.2535294...),
PlanckianTable_Tuvdi(Ti=1002.2222222..., ui=0.4474910..., vi=0.3546700..., di=0.2532771...),
PlanckianTable_Tuvdi(Ti=1003.3333333..., ui=0.4472316..., vi=0.3546924..., di=0.2530251...),
PlanckianTable_Tuvdi(Ti=1004.4444444..., ui=0.4469724..., vi=0.3547148..., di=0.2527734...),
PlanckianTable_Tuvdi(Ti=1005.5555555..., ui=0.4467136..., vi=0.3547372..., di=0.2525220...),
PlanckianTable_Tuvdi(Ti=1006.6666666..., ui=0.4464550..., vi=0.3547595..., di=0.2522710...),
PlanckianTable_Tuvdi(Ti=1007.7777777..., ui=0.4461968..., vi=0.3547817..., di=0.2520202...),
PlanckianTable_Tuvdi(Ti=1008.8888888..., ui=0.4459389..., vi=0.3548040..., di=0.2517697...),
PlanckianTable_Tuvdi(Ti=1010.0, ui=0.4456812..., vi=0.3548261..., di=0.2515196...)]
Returns the shortest distance index in given planckian table using Ohno (2013) method.
Parameters: | planckian_table (list) – Planckian table. |
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Returns: | Shortest distance index. |
Return type: | int |
Examples
>>> from colour import STANDARD_OBSERVERS_CMFS
>>> cmfs = 'CIE 1931 2 Degree Standard Observer'
>>> cmfs = STANDARD_OBSERVERS_CMFS.get(cmfs)
>>> table = planckian_table((0.1978, 0.3122), cmfs, 1000, 1010, 10)
>>> planckian_table_minimal_distance_index(table)
9
Returns the correlated colour temperature Tcp and Δuv from given CIE UCS colourspace uv chromaticity coordinates, colour matching functions and temperature range using Ohno (2013) method.
The iterations parameter defines the calculations precision: The higher its value, the more planckian tables will be generated through cascade expansion in order to converge to the exact solution.
Parameters: |
|
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Returns: | Correlated colour temperature Tcp, Δuv. |
Return type: | tuple |
References
[3] | Ohno, Y. (2014). Practical Use and Calculation of CCT and Duv. LEUKOS, 10(1), 47–55. doi:10.1080/15502724.2014.839020 |
Examples
>>> from colour import STANDARD_OBSERVERS_CMFS
>>> cmfs = 'CIE 1931 2 Degree Standard Observer'
>>> cmfs = STANDARD_OBSERVERS_CMFS.get(cmfs)
>>> uv_to_CCT_Ohno2013((0.1978, 0.3122), cmfs)
(6507.5470349..., 0.0032236...)
Returns the CIE UCS colourspace uv chromaticity coordinates from given correlated colour temperature Tcp, Δuv and colour matching functions using Ohno (2013) method.
Parameters: |
|
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Returns: | CIE UCS colourspace uv chromaticity coordinates. |
Return type: | tuple |
References
[4] | Ohno, Y. (2014). Practical Use and Calculation of CCT and Duv. LEUKOS, 10(1), 47–55. doi:10.1080/15502724.2014.839020 |
Examples
>>> from colour import STANDARD_OBSERVERS_CMFS
>>> cmfs = 'CIE 1931 2 Degree Standard Observer'
>>> cmfs = STANDARD_OBSERVERS_CMFS.get(cmfs)
>>> CCT = 6507.4342201047066
>>> D_uv = 0.003223690901512735
>>> CCT_to_uv_Ohno2013(CCT, D_uv, cmfs)
(0.1978003..., 0.3122005...)
Returns the correlated colour temperature Tcp and Δuv from given CIE UCS colourspace uv chromaticity coordinates using Roberston (1968) method.
Parameters: | uv (array_like) – CIE UCS colourspace uv chromaticity coordinates. |
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Returns: | Correlated colour temperature Tcp, Δuv. |
Return type: | tuple |
References
[5] | Wyszecki, G., & Stiles, W. S. (2000). DISTRIBUTION TEMPERATURE, COLOR TEMPERATURE, AND CORRELATED COLOR TEMPERATURE. In Color Science: Concepts and Methods, Quantitative Data and Formulae (pp. 224–229). Wiley. ISBN:978-0471399186 |
[6] | Adobe Systems. (2013). Adobe DNG Software Development Kit (SDK) - 1.3.0.0 - dng_sdk_1_3/dng_sdk/source/dng_temperature.cpp:: dng_temperature::Set_xy_coord. Retrieved from https://www.adobe.com/support/downloads/dng/dng_sdk.html |
Examples
>>> uv = (0.19374137599822966, 0.31522104394059397)
>>> uv_to_CCT_Robertson1968(uv)
(6500.0162879..., 0.0083333...)
Returns the CIE UCS colourspace uv chromaticity coordinates from given correlated colour temperature Tcp and Δuv using Roberston (1968) method.
Parameters: |
|
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Returns: | CIE UCS colourspace uv chromaticity coordinates. |
Return type: | tuple |
References
[7] | Wyszecki, G., & Stiles, W. S. (2000). DISTRIBUTION TEMPERATURE, COLOR TEMPERATURE, AND CORRELATED COLOR TEMPERATURE. In Color Science: Concepts and Methods, Quantitative Data and Formulae (pp. 224–229). Wiley. ISBN:978-0471399186 |
[8] | Adobe Systems. (2013). Adobe DNG Software Development Kit (SDK) - 1.3.0.0 - dng_sdk_1_3/dng_sdk/source/dng_temperature.cpp:: dng_temperature::xy_coord. Retrieved from https://www.adobe.com/support/downloads/dng/dng_sdk.html |
Examples
>>> CCT = 6500.0081378199056
>>> D_uv = 0.0083333312442250979
>>> CCT_to_uv_Robertson1968(CCT, D_uv)
(0.1937413..., 0.3152210...)
Supported CIE UCS colourspace uv chromaticity coordinates to correlated colour temperature Tcp computation methods.
Aliases:
Returns the correlated colour temperature Tcp and Δuv from given CIE UCS colourspace uv chromaticity coordinates using given method.
Parameters: |
|
---|---|
Returns: | Correlated colour temperature Tcp, Δuv. |
Return type: | tuple |
Raises: | ValueError – If the computation method is not defined. |
Examples
>>> from colour import STANDARD_OBSERVERS_CMFS
>>> cmfs = 'CIE 1931 2 Degree Standard Observer'
>>> cmfs = STANDARD_OBSERVERS_CMFS.get(cmfs)
>>> uv_to_CCT((0.1978, 0.3122), cmfs=cmfs)
(6507.5470349..., 0.0032236...)
Supported correlated colour temperature Tcp to CIE UCS colourspace uv chromaticity coordinates computation methods.
Aliases:
Returns the CIE UCS colourspace uv chromaticity coordinates from given correlated colour temperature Tcp and Δuv using given method.
Parameters: |
|
---|---|
Returns: | CIE UCS colourspace uv chromaticity coordinates. |
Return type: | tuple |
Raises: | ValueError – If the computation method is not defined. |
Examples
>>> from colour import STANDARD_OBSERVERS_CMFS
>>> cmfs = 'CIE 1931 2 Degree Standard Observer'
>>> cmfs = STANDARD_OBSERVERS_CMFS.get(cmfs)
>>> CCT = 6507.4342201047066
>>> D_uv = 0.003223690901512735
>>> CCT_to_uv(CCT, D_uv, cmfs=cmfs)
(0.1978003..., 0.3122005...)
Returns the correlated colour temperature Tcp from given CIE XYZ colourspace xy chromaticity coordinates using McCamy (1992) method.
Parameters: | xy (array_like) – xy chromaticity coordinates. |
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Returns: | Correlated colour temperature Tcp. |
Return type: | numeric |
References
[9] | Wikipedia. (n.d.). Approximation. Retrieved June 28, 2014, from http://en.wikipedia.org/wiki/Color_temperature#Approximation |
Examples
>>> xy_to_CCT_McCamy1992((0.31271, 0.32902))
6504.3893830...
Returns the correlated colour temperature Tcp from given CIE XYZ colourspace xy chromaticity coordinates using Hernandez-Andres, Lee and Romero (1999) method.
Parameters: | xy (array_like) – xy chromaticity coordinates. |
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Returns: | Correlated colour temperature Tcp. |
Return type: | numeric |
References
[10] | Hernández-Andrés, J., Lee, R. L., & Romero, J. (1999). Calculating correlated color temperatures across the entire gamut of daylight and skylight chromaticities. Applied Optics, 38(27), 5703–5709. doi:10.1364/AO.38.005703 |
Examples
>>> xy_to_CCT_Hernandez1999((0.31271, 0.32902))
6500.0421533...
Returns the CIE XYZ colourspace xy chromaticity coordinates from given correlated colour temperature Tcp using Kang et al. (2002) method.
Parameters: | CCT (numeric) – Correlated colour temperature Tcp. |
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Returns: | xy chromaticity coordinates. |
Return type: | tuple |
Raises: | ValueError – If the correlated colour temperature is not in appropriate domain. |
References
[11] | Kang, B., Moon, O., Hong, C., Lee, H., Cho, B., & Kim, Y. (2002). Design of advanced color: Temperature control system for HDTV applications. Journal of the Korean …, 41(6), 865–871. Retrieved from http://cat.inist.fr/?aModele=afficheN&cpsidt=14448733 |
Examples
>>> CCT_to_xy_Kang2002(6504.38938305)
(0.3134259..., 0.3235959...)
Converts from the correlated colour temperature Tcp of a CIE Illuminant D Series to the chromaticity of that CIE Illuminant D Series illuminant.
Parameters: | CCT (numeric) – Correlated colour temperature Tcp. |
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Returns: | xy chromaticity coordinates. |
Return type: | tuple |
Raises: | ValueError – If the correlated colour temperature is not in appropriate domain. |
References
[12] | 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 |
Examples
>>> CCT_to_xy_CIE_D(6504.38938305)
(0.3127077..., 0.3291128...)
Supported CIE XYZ colourspace xy chromaticity coordinates to correlated colour temperature Tcp computation methods.
Aliases:
Returns the correlated colour temperature Tcp from given CIE XYZ colourspace xy chromaticity coordinates using given method.
Parameters: |
|
---|---|
Returns: | Correlated colour temperature Tcp. |
Return type: | numeric |
Supported correlated colour temperature Tcp to CIE XYZ colourspace xy chromaticity coordinates computation methods.
Aliases:
Returns the CIE XYZ colourspace xy chromaticity coordinates from given correlated colour temperature Tcp using given method.
Parameters: |
|
---|---|
Returns: | xy chromaticity coordinates. |
Return type: | tuple |