Compute various forms of deltaE values for a pair of XYZ images
result = scComputeDifference(xyz1,xyz2,whitePt,deltaEVer);
The CIELAB deltaE metric for a pair of XYZ images depends on the white
point and the version of delta E. This routine takes two XYZ images
and white point information, and computes the delta E value requested by
the user.
whitePt should either be a cell array with two white points or, if the
two images have the same white point, whitePt can be a 3-vector.
By default, deltaEVe is the CIELAB 2000 delta E (dE). For backwards
compatibility, it is possible to ask for earlier versions:
deltaEVer = '1976'; or deltaEVer = '1994';
It is also possible to request the luminance, chrominance, or hue errors
that go into the computation of the dE 2000. This are returned if you
ask for deltaEVer = 'chrominance' or deltaEVer = 'luminance' or 'hue'.
These components are always based on the CIELAB 2000 code.
If you would like both the deltaE and the components, you cans set
deltaEVer to 'all'. Then result.dE will be the deltaE and
result.components will be a structure containing the scaled dL, dH and dC
terms from CIELAB dE2000.
Example:
e = scComputeDifference(xyz1,xyz2,whitePt); % deltaE 2000
e = scComputeDifference(xyz1,xyz2,whitePt,'hue'); % hue only
e = scComputeDifference(xyz1,xyz2,whitePt,'luminance');% luminance only