用CRT显示器显示5种频率的目标光栅,通过改变矩形波光栅的平均亮度,测量了9名男性青年在不同平均亮度条件下的对比度觉察阈值,并得出亮度与对比度觉察阈值间的关系曲线,从而探讨人眼在显示器亮度范围内的亮度视觉特性.实验结果表明,不同人眼对频率f=3.79和4.97cpd(周/度)的目标光栅的对比度觉察阈值非常相近,而对频率f=1.23,1.97和9.86cpd的目标光栅的对比度觉察阈值相差甚远;提高显示器亮度可以降低对比度觉察阈值,提高显示器显示图像分辨力,但是随着亮度的增加(达到Weber区域),亮度对分辨力的提高达到一定限度,而且,当亮度在60cd/m2左右时,显示信息效果与人眼视觉特性最匹配.基于对人眼在显示器亮度范围内的亮度视觉特性的研究,为在显示器上进行图像处理、显示器制造、摄影、印刷、配色等研究和应用奠定基础.
The goal gratings of five frequencies with different mean luminance were displayed on a CRT display, the contrast detection thresholds under different condition were measured for 9 young observers, and the curve reflecting the relationship between luminance and contrast detection threshold was obtained. Thus, human vision characteristic for transferring luminance was discussed in the range of luminance of CRT. The experimental results showed that the contrast thresholds of different observers were very similar for gratings with frequencies of 3.79 and 4.97 cpd,while they were quite different for gratings with frequencies of 1.23,1.97 and 9.86 cpd, and the contrast detection threshold could be lowered by increasing the luminance of grating, but the resolving power went to a limit with the luminance increasing, and effect of the CRT display matched with human vision characteristic very well when the luminance was 60 cd/m2 . The results would make a good foundation for research and application in image manipulation, display manufacture, photography, printing, color matching and so on.