# colour.delta_E¶

colour.delta_E(a, b, method='CIE 2000', **kwargs)[source]

Returns the difference $$\Delta E_{ab}$$ between two given CIE L*a*b* or $$J'a'b'$$ colourspace arrays using given method.

Parameters
• a (array_like) – CIE L*a*b* or $$J'a'b'$$ colourspace array $$a$$.

• b (array_like) – CIE L*a*b* or $$J'a'b'$$ colourspace array $$b$$.

• method (unicode, optional) – {‘CIE 2000’, ‘CIE 1976’, ‘CIE 1994’, ‘CMC’, ‘CAM02-LCD’, ‘CAM02-SCD’, ‘CAM02-UCS’, ‘CAM16-LCD’, ‘CAM16-SCD’, ‘CAM16-UCS’, ‘DIN99’} Computation method.

Other Parameters
Returns

Colour difference $$\Delta E_{ab}$$.

Return type

numeric or ndarray

References

Examples

>>> import numpy as np
>>> a = np.array([100.00000000, 21.57210357, 272.22819350])
>>> b = np.array([100.00000000, 426.67945353, 72.39590835])
>>> delta_E(a, b)
94.0356490...
>>> delta_E(a, b, method='CIE 2000')
94.0356490...
>>> delta_E(a, b, method='CIE 1976')
451.7133019...
>>> delta_E(a, b, method='CIE 1994')
83.7792255...
>>> delta_E(a, b, method='CIE 1994', textiles=False)
...
83.7792255...
>>> delta_E(a, b, method='DIN99')
66.1119282...
>>> a = np.array([54.90433134, -0.08450395, -0.06854831])
>>> b = np.array([54.90433134, -0.08442362, -0.06848314])
>>> delta_E(a, b, method='CAM02-UCS')
0.0001034...
>>> delta_E(a, b, method='CAM16-LCD')
0.0001034...