On Contrast Sensitivity in an Image Difference Model.

Abstract

The importance of the human contrast sensitivity function (CSF) in a color image difference metric is examined. The contrast sensitivity function is used to extend traditional color difference equations for use with complex image stimulus. Three CSF models of various complexities are evaluated using psychophysical image difference data. Additionally, two models of spatial frequency adaptation are evaluated. These models adjust the peak sensitivity and general shape of the contrast sensitivity functions to better correlate with complex stimuli.