基于测量最小可分辨对比度的CCD相机成像质量的评价

Evaluation of Imaging Quality of CCD Cameras by Measuring Minimum Resolvable Contrast

针对评价CCD相机成像质量MTF方法的缺点,引入了最小可分辨对比度MRC这个评价指标,并研制了相应测量MRC的系统.在这个系统中采用两个重叠积分球分别对靶标的正反两面照明,通过改变这两个积分球的亮度就可以获得可变的对比度.实验结果表明:测量MRC系统测量亮度的误差可控制在±0.3cd/m2以内;CCD相机的MRC随着空间频率的增加而增加;测量CCD相机的MRC是评价CCD相机成像质量的一种快速有效的方法.

Based on the disadvantages of the MTF for evaluating the imaging quality of CCD cameras,the MRC was presented and the system of measuring MRC was developed,in which two coinciding integrating spheres were proposed to illuminate two sides of the target respectively. The variable contrast could be obtained by regulating the luminance of integrating spheres. Experimental results indicate that the error of measuring luminance is within ±0.3 cd/m^2 ,MRC rises with the increase of the spatial frequency,and the method proposed is a rapid and effective approach to evaluate the imaging quality of CCD cameras.