Study of the Visibility of Color and Form under Mesopic Vision for the Traffic Safety in the Future of Aging Society

本研究旨在预测未来老龄化社会交通安全中，中观视觉下颜色与形态对能见度阈值的影响。测试条件为：1)物体的大小；2)观察物体的视角；3)观察物体与背景的亮度对比。测量是在一个0.5 lx的隔间里进行的，有男有女，有五名受试者，戴着人工瞳孔。在计算机CRT上，由主考人将制备好的消色差圆图案依次呈现给透过还原屏孔径观看的被试。采用极限法确定差异阈值。通过分析被试在CRT上观看物体时的眼动，研究了图形物体与背景的色调对比对吸引力的影响。以草地色、运动场跑道色和中灰色三种不同颜色的背景上的五种颜色作为眼睛刺激进行测试。结果表明：1)在物体视角较大（即物体尺寸较大或距离物体较近）的情况下，差异阈值较低或可见性较高，物体亮度与背景对比度较高。2)当背景的亮度高于物体的亮度时，应该期望有更高的能见度。3)当色相对比度较低，即物体与背景颜色相似时，吸引力会降低。

The purpose of this study is to predict the effects of color and form on the visibility threshold under mesopic vision for the traffic safety in the future of the aging society. The tested conditions were : 1) the size of object : 2) visual angle of the view object and 3) its luminance contrasted against the background. The measurements were taken in a 0.5 lx booth using five subjects, both male and female, wearing artificial pupils. One after the other, the prepared achromatic circle patterns were presented on the computer CRT by the examiner to the subjects who were looking through the aperture of the reduction screeen. The difference thresholds were determined by the limiting method.The effect of the hue contrast between the graphic objects and its background on the attractiveness were also studied by the analysis of eye movement of the subjects looking at the objects on CRT.The five chromatic colors on the three different color of backgrounds, grass color, track color of sport stadium, and medium gray, were tested as the eye stimuli.The results were :1) Lower difference thresholds or higher visibility were found under the conditions of a larger view angle of the object, (namely large sized objects or a shorter distance from the objects), and a higher contrast of the luminance of the object against the background.2) When the luminance of the background is higher than the luminance of the object, higher visibility should be expected.3) The attractiveness will be lower at the combinations of lower contrast of hue, that is similar color of the object and background.