colour.difference.delta_E_DIN99#

colour.difference.delta_E_DIN99(Lab_1: ArrayLike, Lab_2: ArrayLike, textiles: bool = False) NDArrayFloat[source]#

Return the difference \(\Delta E_{DIN99}\) between two given CIE L*a*b* colourspace arrays using DIN99 formula.

Parameters:
  • Lab_1 (ArrayLike) – CIE L*a*b* colourspace array 1.

  • Lab_2 (ArrayLike) – CIE L*a*b* colourspace array 2.

  • textiles (bool) – Textiles application specific parametric factors, \(k_E=2,\ k_{CH}=0.5\) weights are used instead of \(k_E=1,\ k_{CH}=1\).

Returns:

Colour difference \(\Delta E_{DIN99}\).

Return type:

numpy.ndarray

Notes

Domain

Scale - Reference

Scale - 1

Lab_1

L_1 : [0, 100]

a_1 : [-100, 100]

b_1 : [-100, 100]

L_1 : [0, 1]

a_1 : [-1, 1]

b_1 : [-1, 1]

Lab_2

L_2 : [0, 100]

a_2 : [-100, 100]

b_2 : [-100, 100]

L_2 : [0, 1]

a_2 : [-1, 1]

b_2 : [-1, 1]

References

[ASTMInternational07]

Examples

>>> import numpy as np
>>> Lab_1 = np.array([60.2574, -34.0099, 36.2677])
>>> Lab_2 = np.array([60.4626, -34.1751, 39.4387])
>>> delta_E_DIN99(Lab_1, Lab_2)  
1.1772166...