CCD像素响应不均匀性的校正方法

Correction of CCD pixel nonuniformity

从理论上分析了CCD暗电流和光电响应不均匀性产生的原因,根据光电响应模型提出了CCD像素光电响应不均匀性的校正方法,给出了像素光电响应不均匀性的校正系数用以计算校正量;并针对实际情况中干扰光的影响,提出了采用变波长去除干扰方法,对校正方法进行了修正;最后通过仿真对算法进行了验证。结果表明,能量和噪声的不同对算法的影响不大,校正量是随着光信号能量分布变化的,标定过程不受信号的影响,具有自适应性。该校正方法可以有效地减小CCD像素光电响应不均匀性带来的图像噪声。

The causes for CCD dark current and photoelectric response are theoretically analyzed. An algorithm based on the photoelectric signal is proposed for correction of CCD photoelectric response nonuniformity, and a coefficient is given for calculation of electronic quantity to be corrected as well. The interference is eliminated by varying the wavelength according to the effect of actual interference light. Simulation results indicate that the algorithm proposed can be used to effectively reduce the image noise resulting from CCD pixel photoelectric response nonuniformity.