The chromad function calculates chromatic adaptation matrices for the CIE 1931 chromaticity. 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:
M = chromad('source','target','method','observer')
Where:
Parameter | Description |
M | Is the resulting chromatic adaption 33 matrix. |
'source' | Defines the source whitepoint, see list below or use vector triplet [x y z]. |
'target' | Defines the target whitepoint, see list below or use vector triplet [x y z] . |
'method' (optional) | Defines the calculation method: – ‘XYZ’ (default) – ‘vonKries’ – ‘Bradford’ |
'observer' (optional) | CIE standard observer: – ‘xyz’ = CIE 2° observer (default) – ‘xyz10’ = CIE 10° observer |
Reference whitepoints:
Reference | Description |
'A' | standard illuminant A |
'C' | not official 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' | lluminant daylight XX00 K – not official standard |
'DXXXX' | illuminant daylight XXXX K – not official 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' | Phosphor-type LED |
'LED-B2' | Phosphor-type LED |
'LED-B3' | Phosphor-type LED |
'LED-B4' | Phosphor-type LED |
'LED-B5' | Phosphor-type LED |
'LED-BH1' | Hybrid-type LED |
'LED-RGB1' | RGB-type LED |
'LED-V1' | violet pumped phosphor-type LED |
'LED-V2' | violet pumped phosphor-type LED |
Examples:
Chromatic adaptation matrix for transformation from reference whitepoint A to reference whitepoint D65 with default ‘XYZ’ method:
M = chromad('A','D65')
Result:
M = Diagonal Matrix 0.8653 0 0 0 1.0000 0 0 0 3.0593
Chromatic adaptation matrix for transformation from reference whitepoint D65 to reference whitepoint FL2 with ‘vonKries’ method:
M = chromad('D65','FL2','vonKries')
Result:
M = 1.0300 0.1030 -0.0831 0.0113 0.9917 -0.0023 0 0 0.6182
Chromatic adaptation matrix for transformation from reference whitepoint D50 to reference whitepoint FL11 with ‘Bradford’ method for CIE 10° observer:
M = chromad('D50','FL1','Bradford','xyz10')
Result:
M = 0.9578 -0.0224 0.0539 -0.0284 1.0127 0.0182 0.0102 -0.0168 1.2767
Reference
Bruce Lindbloom, Chromatic adaptation: http://www.brucelindbloom.com/Eqn_ChromAdapt.html
Colorimetry, 4th Edition. Commission International de l’Éclairage (CIE), Vienna Austria, 2018, ISBN: 978-3-902842-13-8 , (DOI: 10.25039/TR.015.2018).