Contrast-detail characteristic evaluations of several display devices

Abstract

The contrast-detail characteristic of a display system is a powerful tool for evaluating displayed image quality. It takes into account the physical properties of the display, the psychophysical aspects of the observer, and the viewing conditions. It is a more sensitive measurement of the displayed image quality than a simple Society of Motion Picture and Television (SMPTE) pattern. Yet, it is relatively simple to measure and requires no special equipment or analysis tools. In this presentation, the results of the evaluation of several cathode ray tube (CRT) monitors and a digital projector will be presented. Contrast-detail characteristics of these display devices were measured under various gamma and display settings. The results show excellent intraobserver and interobserver variance (<1 step on the grayscale). Extraneous light, such as room lighting, affects the contrast threshold more severely at low background levels more than at high background. Gamma settings on graphics adapters affect the shapes of the contrast-detail curve for all display types. Gamma settings of approximately 2.0 result in a better contrast threshold for both high and low background brightness. The results show complex differences in contrast-detail characteristics for different display types. The digital projector display not only has significantly worse performance than CRT monitors, but also is affected more by extraneous light. High-brightness monitors with optimal monitor and graphics adapter settings have better performance than color or low-brightness monitors. However, under some settings, the performance of high-brightness monitors is not always better at all object sizes and background levels.