<title>Design of a spatial-chromatic human vision model for evaluating full-color display systems</title>

Abstract

Two general characteristics of full-color display systems which are known to impact image quality include the ability of the display system to transfer modulation (chromatic as well as achromatic) and the degree to which the display system adds noise (chromatic and achromatic) to the signal. This paper describes a model of human spatial-chromatic vision and a corresponding procedure for using the model to evaluate color display systems. Together the proposed model and procedure constitute a color image quality metric which is responsive to the modulation transfer and noise generating characteristics of a display system. The proposed human vision model employs processing stages which simulate blurring by the optics of the eye, linear spectral absorption by three classes of cone, addition of internal noise, nonlinear transduction by retinal mechanisms, derivation of opponent-color images, and calculation of the responses of linear spatial mechanisms with finite spatial frequency and orientation bandwidth. A summary of the modulation detection, discrimination, and suprathreshold contrast perception performance of the model is presented and compared with human performance data from the visual science literature. A procedure for evaluating display systems using the model is described and the results of several analyses of display systems are presented. High correlations between predictions made by the model and the results of image quality studies from the display design literature have been obtained with no free parameters in the model. The results of the validation studies conducted so far suggest that the proposed method for evaluating color display systems is viable and warrants critical examination.