Abstract— The purpose of this investigation was to determine if color differences can improve legibility and compensate for insufficient luminance contrast. Several authors previously have answered this question positively on the basis of performance experiments. We argue that a valid answer cannot be given unless subjective data are used. In four experiments, subjective ratings were collected pertaining to multicolor CRT text displays. The displays were systematically varied with respect to both luminance contrast and chromaticity contrast. The results indicate that chromaticity contrast and luminance contrast are additive only under specific conditions. Chromaticity contrast cannot improve legibility if an acceptable level of luminance contrast is present. Generally, chromaticity contrast cannot be substituted for luminance contrast.

Abstract— The correct estimation of the gamma exponent describing the tone‐reproduction curve of a display is an important step in color management. Several methods for visual gamma estimation have been proposed. In this study, the theoretical merits and practical problems of a number of these methods are discussed and compared, and improvements are suggested. A new method to compare gamma models with different numbers of parameters is introduced. In an experiment, spatial and temporal brightness‐matching methods were tested with 32 untrained subjects working on a CRT and an LCD with different resolutions under office and low‐illumination conditions. Illumination had no effect on gamma estimations. Subjects had great difficulties with spatial brightness matching at low resolutions. Temporal and spatial visual brightness matching for untrained subjects showed a larger gamma than photometric fits.

No abstract

A new visual display quality assessment method to be used on the work floor is developed. It covers important aspects like system configuration, software applications, display settings, user behavior, display wear and physical environment, which are not included in the current ISO 9241-3 standard physical laboratory measurement methods.

Abstract— The correct setting of the black level is an important step in the (re)calibration of an electronic display. This study looks at the consequences of black‐level offset, the possibilities for display characterization with offset, offset correction, and the ability of average untrained users to visually correct the black‐level setting with the contrast and brightness controls on the display. In an experiment, 32 subjects were asked to optimally set the black level according to two types of instructions (short and extensive, between subjects) under two levels of illumination (low and office, between subjects) for two types of displays (CRTs and LCDs, within subjects). Most subjects were not able to set the black level near optimal for either display, with any combination of instruction and illumination level. The LCD did not have an optimal black level. For the CRT, optimal black level did not provide minimal differences with the sRGB standard tone reproduction curve.