In-field evaluation of the image quality of electronic display devices

Abstract

This paper describes a CCD camera, which was developed for in-field evaluation of the image quality of electronic display devices like Cathode Ray Tube displays (CRTs) and Liquid Crystal displays (LCDs). Contrary to traditional CCD cameras used for image quality evaluation, this camera does not require a sophisticated x– y– z translation stage for mounting and adjustment. Instead it is handheld and pressed by gentle pressure against the display. It is controlled by a software package which was originally developed for the display calibration according to the DICOM 14 GSDF (Grayscale Standard Display Function). This software package controls the camera gain when measurements are made at different display luminance, displays test patterns, performs image analysis and displays the result of the measurements and calculations. Initial work concentrated on the measurement of the modulation transfer function (MTF) of a CRT derived from the line spread function. The obtained MTF deviates only minimally from those obtained with a high performance CCD camera on the same CRT.