Abstract

This erratum corrects an equation in Appl. Opt. 57, 8751 (2018) [CrossRef]  .

© 2019 Optical Society of America

CIE [1] has recommended a formula for the number of equal perceptible differences (nEPD) of luminance (cd/m2) between a visual-contrast luminance (L) and its adjacent background luminance (Lb). An incorrect equation, specifically Eq. (4), was given [2] for the derivative of the recommended formula with respect to L, for negative contrasts (L<Lb). The correct equation is

dnEPD/dL=3.0705{[1k+b(1k)]/{L+.39+(LbL)[k+b(1k)]}(1k)/[L+.39+k(LbL)]},
where k and b are parameters of nEPD [1, 2].

Reassuringly, the graphs, statistics and conclusions of [2] were based on a form of Eq. (1), so they remain correct.

REFERENCES

1. CIE, “Grey-scale calculation for self-luminous devices,” CIE 228:2018 (CIE, 2018).

2. R. C. Carter, “Suprathreshold gray scale is implied by thresholds,” Appl. Opt. 57, 8751–8756 (2018). [CrossRef]  

References

  • View by:

  1. CIE, “Grey-scale calculation for self-luminous devices,” (CIE, 2018).
  2. R. C. Carter, “Suprathreshold gray scale is implied by thresholds,” Appl. Opt. 57, 8751–8756 (2018).
    [Crossref]

2018 (1)

Appl. Opt. (1)

Other (1)

CIE, “Grey-scale calculation for self-luminous devices,” (CIE, 2018).

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Equations (1)

Equations on this page are rendered with MathJax. Learn more.

d nEPD / d L = 3.0705 { [ 1 k + b ( 1 k ) ] / { L + .39 + ( L b L ) [ k + b ( 1 k ) ] } ( 1 k ) / [ L + .39 + k ( L b L ) ] } ,

Metrics