S

M. E. Rudd and D. Popa Vol. 24, No. 10 /October 2007 /J. Opt. Soc. Am. A 3335

Stevens’s brightness law, contrast gain control,and edge integration in achromatic color

perception: a unified model: errata

Michael E. Rudd1,* and Dorin Popa2

1Howard Hughes Medical Institute and Department of Physiology and Biophysics, University of Washington,Seattle, Washington, USA

2Department of Psychology, University of Washington, Seattle, Washington, USA*Corresponding author: mrudd@u.washington.edu

Received August 28, 2007;posted August 28, 2007 (Doc. ID 86614); published September 24, 2007

Several math errors that appeared in a paper by Rudd and Popa [J. Opt. Soc. Am. A 24, 2766 (2007)] are cor-rected.

OCIS codes: 330.1720, 330.4060, 330.4270, 330.5020, 330.5510, 330.7310.

Ntge

R

everal errors were published in [1].Equation (8) should read

��n→m�k = ��n→m�k�1 −dk

s�n→m�k�+

. �1�

Equation (9) should read

��dk� = w1k* + �w1k

* �2��2→1�k�1 −dk

s�2→1�k�+

+ w2k* �1��1→2�k�1 −

dk

s�1→2�k�+��log Fk − log B�.

�2�

Equation (A3) should read

1084-7529/07/103335-1/$15.00 © 2

c0−1�c1 + �c2 + c3dT�+ + �c4 + c5dT�+ + �c6 + �c7 + c8dT�+

+ �c9 + c10dT�+�log ST�. �3�

Equation (A5) should read

log � = log � + � log Sk. �4�

ote that Eq. (4) follows directly from Eq. (1) of [1], withhe understanding that I=Sk. According to the edge inte-ration model, both � and � are functions of dk, as is madexplicit by Eqs. (A6b) and (A6c) of [1].

EFERENCES1. M. E. Rudd and D. Popa, “Stevens’s brightness law,

contrast gain control, and edge integration in achromaticcolor perception: a unified model,” J. Opt. Soc. Am. A 24,

2766–2782 (2007).

007 Optical Society of America