The perception and measurement of contrast: the influence of gaps between display elements

• Published in: Behaviour & information technology Vol. 13; no. 5; pp. 320 - 327
• Main Authors: SPENKELINK, GERD P. J., BESUIJEN, KO
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.09.1994
• ISSN: 0144-929X; 1362-3001
• DOI: 10.1080/01449299408914612

The influence of the luminance of the gap between display elements of flat panel displays (FPDs) on perceived contrast was investigated. Twelve black-on-white FPDs, differing systematically with respect to foreground, background, and gap luminance, were simulated in an experiment. Twelve subjects rated each simulation on u scale, measuring several aspects of image quality, and performed a search task with each simulated FPD. The aims of the research were (a) to validate and assess the reliability of the rating scale items concerning contrast; (b) to relate subjective to objective measures; (c) to find out if ratings improve if raters perform a task with the rated objects; and (d) to evaluate a metric for expressing FPD contrast that we recently proposed. It is concluded that (a) the scale items are reliable if the rated objects vary on the property under concern; several items consistently measured subjective contrast; (b) subjective and objective contrast were strongly related in a linear fashion; (c) without actually using the stimuli in a working task, raters were capable of producing reliable and valid ratings; and (d) the proposed effective luminance modulation (M r ) metric did, but ordinary luminance modulation did not correspond to perceived contrast. Based on this latter finding we recommend that an alternative contrast measurement procedure based on the (M r ) metric is further validated for wide gaps and negative polarity displays.