无光照条件下CMOS图像传感器噪声分析

摘要

The noises of images form D90 camera using CMOS image sensor in different exposure times and without outside illumination are analyzed. The system noise does not increase according to the increased exposure time, so the dark current is very low. And system noise in the center of the CMOS image sensor is lower than in the marginal area. And the formula to calculate the pixel's noise according to the coordi nate is presented.%在无光照条件下,对采用CMOS图像传感器的尼康D90相机在不同的曝光时间下进行拍摄实验,分析CMOS图像传感器在不同曝光时间下的暗电流噪声以及系统噪声在传感器像面上的空间分布.得出如下结论:系统噪声并没有随曝光时间增加而增大的趋势,因此,系统的暗电流噪声比较小；而整体噪声在不同的曝光时间下,都有在空间分布上有像面外围较大而像面中间较小的情况,根据该分布给出计算不同位置像素系统噪声大小的公式.