Modeling Luminance Perception at Absolute Threshold

Here we provide a detail comparison of different dark noise approaches applied to several CG and real world images. Notice how various types of noise look behave differently on bright and dark background. E.g. the dark noise being purely additive has the same magnitude regardless of the image luminance. Our approach, on the other hand, generates more noise in very dark regions where little photons are available to the eye and the spontaneous rod events may prevail. The noise in brighter region then slowly disappears as the number of arriving photons become sufficiently large (hundreds per second and rod).