光源光强对颜色对比度的影响研究

摘要

In the process of color signal imaging,the intensity of illumination affects spectral power distribution and color temperature ,which is correlated to color contrast. This paper studies the relationship between the in-tensity of illumination and color contrast. PWM pulse code regulating is used to adjust the intensity of illumina-tion. The variable law of color contrast with the intensity of illumination is explored and the average color dif-ference in CIEL*a*b* color space is applied to evaluate the color contrast of colored surface. The best PWM grade is then chosen according to the maximum average color difference.%　　彩色图像成像时，光源的亮度变化影响着光源的光谱相对功率分布，影响着照明光源的色温，与成像后的检测目标对比度密切相关。因此研究在光源光谱不变的条件下，光源的亮度变化对颜色对比度的影响。光源的亮度调节采用PWM脉冲编码调节，分析了色块对比度随着光源的亮度变化规律，在CIEL*a*b*空间利用色差来评定色块间的对比度，根据最大色差选择了一个最佳的光源照度等级。