Colour Difference

Delta E

colour

delta_E(a, b[, method])	Return the difference \(\Delta E_{ab}\) between two given CIE L*a*b*, \(IC_TC_P\), or \(J'a'b'\) colourspace arrays using given method.
DELTA_E_METHODS	Supported \(\Delta E_{ab}\) computation methods.

CIE 1976

colour.difference

JND_CIE1976	Just Noticeable Difference (JND) according to CIE 1976 colour difference formula, i.e. Euclidean distance in CIE L*a*b* colourspace.
delta_E_CIE1976(Lab_1, Lab_2)	Return the difference \(\Delta E_{76}\) between two given CIE L*a*b* colourspace arrays using CIE 1976 recommendation.

CIE 1994

colour.difference

delta_E_CIE1994(Lab_1, Lab_2[, textiles])

Return the difference \(\Delta E_{94}\) between two given CIE L*a*b* colourspace arrays using CIE 1994 recommendation.

CIE 2000

colour.difference

delta_E_CIE2000(Lab_1, Lab_2[, textiles])

Return the difference \(\Delta E_{00}\) between two given CIE L*a*b* colourspace arrays using CIE 2000 recommendation.

CMC

colour.difference

delta_E_CMC(Lab_1, Lab_2[, l, c])

Return the difference \(\Delta E_{CMC}\) between two given CIE L*a*b* colourspace arrays using Colour Measurement Committee recommendation.

ITP

colour.difference

delta_E_ITP(ICtCp_1, ICtCp_2)

Return the difference \(\Delta E_{ITP}\) between two given \(IC_TC_P\) colour encoding arrays using Recommendation ITU-R BT.2124.

Luo, Cui and Li (2006)

colour.difference

delta_E_CAM02LCD(Jpapbp_1, Jpapbp_2)	Return the difference \(\Delta E'\) between two given Luo et al. (2006) CAM02-LCD colourspaces \(J'a'b'\) arrays.
delta_E_CAM02SCD(Jpapbp_1, Jpapbp_2)	Return the difference \(\Delta E'\) between two given Luo et al. (2006) CAM02-SCD colourspaces \(J'a'b'\) arrays.
delta_E_CAM02UCS(Jpapbp_1, Jpapbp_2)	Return the difference \(\Delta E'\) between two given Luo et al. (2006) CAM02-UCS colourspaces \(J'a'b'\) arrays.

Li, Li, Wang, Zu, Luo, Cui, Melgosa, Brill and Pointer (2017)

colour.difference

delta_E_CAM16LCD(Jpapbp_1, Jpapbp_2)	Return the difference \(\Delta E'\) between two given Li et al. (2017) CAM16-LCD colourspaces \(J'a'b'\) arrays.
delta_E_CAM16SCD(Jpapbp_1, Jpapbp_2)	Return the difference \(\Delta E'\) between two given Li et al. (2017) CAM16-SCD colourspaces \(J'a'b'\) arrays.
delta_E_CAM16UCS(Jpapbp_1, Jpapbp_2)	Return the difference \(\Delta E'\) between two given Li et al. (2017) CAM16-UCS colourspaces \(J'a'b'\) arrays.

DIN99

colour.difference

delta_E_DIN99(Lab_1, Lab_2[, textiles])

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

Standardized Residual Sum of Squares (STRESS) Index

colour

index_stress(d_E, d_V[, method])	Compute the Kruskal's Standardized Residual Sum of Squares (:math:`STRESS`) index according to given method.
INDEX_STRESS_METHODS	Supported \(STRESS\) index computation methods.

colour.difference

index_stress_Garcia2007(d_E, d_V)

Compute the Kruskal's Standardized Residual Sum of Squares (:math:`STRESS`) index according to García, Huertas, Melgosa and Cui (2007) method.

Huang et al. (2015) Power-Functions

colour.difference

power_function_Huang2015(d_E[, coefficients])

Improve the performance of the \(\Delta E\) value for given coefficients using Huang, Cui, Melgosa, Sanchez-Maranon, Li, Luo and Liu (2015) power-function: \(d_E^{\prime}=a*d_{E^b}\).