Pupil size estimation model based on luminance and chromaticity spatial distribution.

As an important index in studies on vision and display technology, pupil size controls the amount of the light entering human eye. Eye tracking systems are normally used to measure the pupil size while a pupil size estimation model can be applied when actual measurement is not available. The weighting functions of the reported pupil size estimation models show radial symmetry, which contradicted the radial asymmetric distribution of photoreceptors on the retina. Chromaticity spatial distribution has not been taken into consideration either. In this paper, the perceptual experiments are carried out with patterned and colored stimuli to evaluate the spatial and color varying effect of luminance to the pupil. A revised corneal flux density is proposed, which shows a high correlation with pupil diameters. Based on this, a pupil size estimation model is proposed. Pupil diameters can be calculated after inputting luminance and chromaticity spatial distribution matrixes. After verification, this model can be applied to indoor scenes with different lighting temperatures within the general illumination range. This model should be useful in scientific and practical applications where pupil diameter matters. [ABSTRACT FROM AUTHOR]