Figure 11.

A binocular contrast combination model is modified to predict binocular luminance summation. The luminance inputs of target and background first go through a luminance compressor (LOG) (Equation 4), and then two eyes' luminance contrasts (edge contrast: Equation 15) are extracted and binocularly combined. The binocular contrast combination model can be either the power summation model (Legge, 1984), the normalization model (Moradi & Heeger, 2009), the first stage of the two-stage model (Meese et al., 2006) or the first stage of the two-stage + Maximum operator model (Georgeson et al., 2016).