摘要
本文通过一组人体实验,研究了在通常室内光照条件下人眼对黑白层次、三基色的灰度层次的分辨能力,建立了人眼对灰度分辨的数学模型,并给出了定量数据。本文得到以下结论:当人眼在通常的室内环境中观察图象监视器屏幕时,人眼对黑白灰度级的分辨力与对三基色灰度级的分辨力没有显著差异。在0～255所表示的图象灰度显示系统中,灰度级数为8、16、32时的人眼正确识别率分别约为93.16%、68.75%、45.31%;本文给出了人眼视觉内部等效噪声模型:这种噪声是一种均值为0,方差为64的高斯白噪声,在人眼识别信号的过程中是加性噪声。使用这个模型计算出的结果与人体实验结果是相符的。基于本文的结论,在人机视觉信息交换中,为了使得人机彼此匹配和适应,应尽量只使用全黑和全白两种灰度做为亮度标识,若想在标识中使用多个灰度级别,灰度级别以不超过4个为宜。本文研究的结论对于合理地设计画面灰度标识使之符合人机匹配原则具有意义。
A group of physiological experiments was designed to study the gray level resolution ability of human vision in blackwhite and three primary colors under normal indoor illumination. A gray level resolution model of human eyes was developed, and a quantitative result was presented. It was found that there was no obvious difference in visual resolutions of black-white and three primary colors when a subject observed a screen of the monitor under normal indoor illumination. In the image system displayed from 0 to 255 gray levels the correct resolving power of gray levels 8, 16, 32 was about 93.16%, 68.75%, 45.31%, respectively. An equivalent intrinsic noise model of human vision was proposed. It is a weighted noise in process of distinguishing signals. It is Gaussian white noise with a mean of 0 and the a variance of 64. The result using this model corresponds with that of physiological experiments. Based on above findings, two gray levels, full black and white, should be used as brightness symbols in man-machine vision communications. Generally the number of gray levels should not be more than 4 if more gray levels must be used. The conclusions given in this paper are significant in designing gray level symbols of a pattern to match the visual needs in the man-machine system.
出处
《航天医学与医学工程》
CAS
CSCD
1991年第1期51-55,共5页
Space Medicine & Medical Engineering
关键词
视觉
灰度
分辨力
噪声
色觉
visual performance, gray scale, colour vision, resolving power, trichromat
