Gateway routine for calculating delta E between corresponding XYZ values
[dEab, errComponents] = deltaEab(XYZ1,XYZ2,whitePnt,[deltaEVer='2000'])
Calculate the CIE delta E between two different colors in CIELAB space.
The CIE delta E standard is a fundamental tool of color science. The
metric is described in a wide variety of textbooks. It has gone
through a series of refinements over the years. The latest is this
one, the CIEDE2000. Earlier versions, dating to 1976, were also
defined.
XYZ1 and XYZ2 define the corresponding sets of XYZ data. These are
stored either XW (space-wavelength) or RGB Image format.
If the data are XW format, then they a are (n*m, 3) matrices.
In RGB image format they are 3D arrays of n x m x 3.
whitePnt is the white point for the CIELAB calculation. If whitePnt is
a cell array, then the first entry is the white point of xyz1 and the
second of xyz2.
In the normal (full delta E) mode, deltaEVe refers to the year of the
delta E calculation: '1976','1994' or '2000'. The default is 2000.
It is also possible to request only the luminance or chrominance part of
the delta E error. In this case, the deltaEVer is 'chroma' or
'luminance'. These are always based on the CIELAB 2000 code.
The returned dEab values have the same format (XW or RGB) as the input
XYZ values.
Example:
dataXYZ1 = imageDataXYZ(vci1,roiLocs); whitePnt{1} = imageGet(vci1,'whitepoint');
dataXYZ2 = imageDataXYZ(vci2,roiLocs); whitePnt{2} = imageGet(vci2,'whitepoint');
dEab = deltaEab(dataXYZ1,dataXYZ2,whitePnt)
Copyright ImagEval Consultants, LLC, 2003.