cieCAM02

cieCAM02

The cieCAM02 function determines the colour appearance model parameters of the CIECAM02 forward model, as in CIE 159:2004. For the inverse model, see cieCAM02inv. 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:

[cam,p] = cieCAM02(XYZ,wp,cond,La,Yb)

Where:

Parameter	Description
`cam`	Is the return struct of the colour appearance model: J = lightness C = chroma H = hue quadrature M = colourfulness Q = brightness s = saturation a = corresponding cartesian coordinates: $a_c, a_M, a_s$ b = corresponding cartesian coordinates: $b_c, b_M, b_s$
`p`	Is the return struct with several parameters for the inverse model function cieCAM02inv.
`XYZ`	Is the input vector triplet or matrix sample(s) [X Y Z].
`wp`	Defines the test illuminant white point, vector triplet [X Y Z].
`cond`	Defines the surround condition: ‘ave’ average surround (default) ‘dim’ dim surround ‘dark’ dark surround
`La`	Is the corresponding luminance of the adapting field, numeric. Default: XYZ(2)/5
`Yb`	Is the corresponding background luminance, numeric. Default: Yb = wp(2)/5

Examples

CIECAM02 forward transformation with CIECAM02 parameter struct:

% define parameters
XYZ = [19.31 23.93 10.14];
wp = [98.88 90 32.02];
cond = 'ave';
La = 20;
Yb = 18;
% CIECAM02 transfromation
[cam,p] = cieCAM02(XYZ,wp,cond,La,Yb)
% inverse transformation
XYZ = cieCAM02inv(cam,p)

See also: cieCAM02inv

Result:

cam =

  scalar structure containing the fields:

    J = 47.686
    C = 36.054
    H = 232.69
    M = 29.759
    Q = 113.84
    s = 51.128
    ac = -35.896
    bc = -3.3715
    am = -29.629
    bm = -2.7829
    as = -50.904
    bs = -4.7812

p =

  scalar structure containing the fields:

    wp =

       98.880   90.000   32.020

    cond = ave
    c = 0.6900
    Nc = 1
    F = 1
    La = 20
    Yb = 18
    k = 9.9010e-03
    FL = 0.4642
    n = 0.2000
    Nbb = 1.0003
    z = 1.9272
    Aw = 30.453
    D = 0.8584

XYZ =

   19.310   23.930   10.140

Reference

CIE 159:2004, A colour appearance model for colour management systems: CIECAM02, Commission Internationale de l’Eclairage (CIE), Vienna Austria, ISBN: 978 3 901906 29 9. URL: https://cie.co.at/publications/colour-appearance-model-colour-management-systems-ciecam02

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