A contrast perception matching based HDR tone-mapping operator

In 2008, Mantiuk et al proposed a display adaptive tone-mapping operator [Mantiuk et al. 2008]. It adapted Daly's visible differences predictor [Daly 1993] and Wilson's transducer function [Wilson 1980; Wilson and Gelb 1984] to measure the response of contrast in human visual system. The transducer function is expressed as: where ΦQ(C) represents the response of a contrast stimulus. C is the physical contrast of a stimulus, and S is the sensitivity of this type of contrast stimuli with certain frequency, orientation, background luminance values, etc. Q is a empirical parameter that falls in a wide range of [2.0, 6.0] across different experiments. It suggests the value of Q is adaptive to experimental conditions. A simple adaption of Equ. 1 with fixed Q may bring unexpected errors.