A general framework is presented for the development of image histogram modification techniques based on models of the human visual system. A new model is then derived from measurements of the nonlinear characteristic of the visual system reported in the psychophysiology literature, leading to the development of a new histogram modification technique. A modified version of a previously proposed technique, Mokrane’s transformation, is introduced and shown to be a special case of this more general technique. Also discussed is another special case, called quadratic hyperbolization. Examples are provided showing that images processed with the new technique may have greater intelligibility than when processed with existing methods of histogram modification.