IEVref:845-23-066ID:
Language:enStatus: Standard
Term: excitation purity
Synonym1:
Synonym2:
Synonym3:
Symbol: pe
Definition: quotient NC/ND of two collinear distances on the chromaticity diagram of the CIE 1931 or 1964 standard colorimetric systems, the first distance being that between the point C representing the colour stimulus considered and the point N representing the specified achromatic stimulus, the second distance being that between the point N and the point D on the spectrum locus at the dominant wavelength of the colour stimulus considered, leading to the following expressions:

p e = y− y n y d − y n MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX garuavP1wzZbItLDhis9wBH5garmWu51MyVXgaruWqVvNCPvMCG4uz 3bqee0evGueE0jxyaibaieYdi9WrpeeC0lXdh9vqqj=hEeea0xXdbb a9frFj0=OqFfea0dXdd9vqaq=JfrVkFHe9pgea0dXdar=Jb9hs0dXd bPYxe9vr0=vr0=vqpWqaaeaaciWacmGadaGadeaaeaGaauaaaOqaai aadchadaWgaaWcbaGaaeyzaaqabaGccqGH9aqpdaWcaaqaaiaadMha cqGHsislcaWG5bWaaSbaaSqaaiaab6gaaeqaaaGcbaGaamyEamaaBa aaleaacaqGKbaabeaakiabgkHiTiaadMhadaWgaaWcbaGaaeOBaaqa baaaaaaa@4376@

and

p e = x− x n x d − x n MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX garuavP1wzZbItLDhis9wBH5garmWu51MyVXgaruWqVvNCPvMCG4uz 3bqee0evGueE0jxyaibaieYdi9WrpeeC0lXdh9vqqj=hEeea0xXdbb a9frFj0=OqFfea0dXdd9vqaq=JfrVkFHe9pgea0dXdar=Jb9hs0dXd bPYxe9vr0=vr0=vqpWqaaeaaciWacmGadaGadeaaeaGaauaaaOqaai aadchadaWgaaWcbaGaaeyzaaqabaGccqGH9aqpdaWcaaqaaiaadIha cqGHsislcaWG4bWaaSbaaSqaaiaab6gaaeqaaaGcbaGaamiEamaaBa aaleaacaqGKbaabeaakiabgkHiTiaadIhadaWgaaWcbaGaaeOBaaqa baaaaaaa@4372@

where (x, y), (xn, yn), (xd, yd) are the x, y chromaticity coordinates of the points C, N and D respectively

Note 1 to entry: In the case of purple stimuli, the monochromatic stimulus is replaced by a stimulus whose chromaticity is represented by a point on the purple boundary.

Note 2 to entry: The formulae in x and y are equivalent, but greater precision is given by the formula which has the greater value in the numerator.

Note 3 to entry: The excitation purity, pe, is related to the colorimetric purity, pc, by the equation:

p e = p c y y d MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX garuavP1wzZbItLDhis9wBH5garmWu51MyVXgaruWqVvNCPvMCG4uz 3bqee0evGueE0jxyaibaieYdi9WrpeeC0lXdh9vqqj=hEeea0xXdbb a9frFj0=OqFfea0dXdd9vqaq=JfrVkFHe9pgea0dXdar=Jb9hs0dXd bPYxe9vr0=vr0=vqpWqaaeaaciWacmGadaGadeaaeaGaauaaaOqaai aadchadaWgaaWcbaGaaeyzaaqabaGccqGH9aqpdaWcaaqaaiaadcha daWgaaWcbaGaae4yaaqabaGccaWG5baabaGaamyEamaaBaaaleaaca qGKbaabeaaaaaaaa@3F63@

Note 4 to entry: The excitation purity has unit one.

Note 5 to entry: This entry was numbered 845-03-48 in IEC 60050-845:1987.


Publication date:2020-12
Source
Replaces:
Internal notes:
CO remarks:
TC/SC remarks:
VT remarks:
Domain1:
Domain2:
Domain3:
Domain4:
Domain5: