colour.constants.cie Module¶

CIE Constants¶

Defines CIE constants.

colour.constants.cie.CIE_E = 0.008856451679035631¶

CIE $\epsilon$ constant.

CIE_E : numeric

Notes

• The original CIE value for $\epsilon$ is $\epsilon=0.008856$, Bruce Lindbloom has shown that this value is causing a discontinuity a the junction point of the two functions grafted together to create the Lightness $L^*$ function.

  That discontinuity can be avoided by using the rational representation as follows: $\epsilon=216/24389$.

References

[1]	http://brucelindbloom.com/index.html?LContinuity.html (Last accessed 24 February 2014)

colour.constants.cie.CIE_K = 903.2962962962963¶

CIE $k$ constant.

CIE_K : numeric

Notes

• The original CIE value for $k$ is $k=903.3$, Bruce Lindbloom has shown that this value is causing a discontinuity a the junction point of the two functions grafted together to create the Lightness $L^*$ function.

  That discontinuity can be avoided by using the rational representation as follows: $k=24389/27$.

References

[2]	http://brucelindbloom.com/index.html?LContinuity.html (Last accessed 24 February 2014)