本文讨论了复杂背景下采用电子倍增CCD实现光子计数成像的处理策略,提出了一种二次阈值滤波方法并通过实验验证其有效性。根据电子倍增CCD的成像模型,将电子倍增CCD的输出图像表示为光子事件、偏置噪声和伪光子事件噪声的集合。通过采集多幅电子倍增CCD的输出图像,将光子事件检测问题转化为标准的二元假设检测问题。利用利用贝叶斯判决,可以找到光子事件检测的最佳检测法则,使得光子事件的误判代价达到最小,从而检测出光子事件及其空间分布特征。通过实验对比可以发现,本文提出的方法明显优于普通的累加积分方法,适用于生物微弱光检测等超低照度下的成像等领域。%In this paper, a double-threshold filter strategy is proposed and experimentally tested to improve the accuracy of photon counting imaging with an electron multiplying charge-coupled device (EMCCD), by taking into account the addition bias noise and Pseudo-photon noise during photon counting mode. Photon counting event detection is achieved by using amplitude threshold and frequency threshold filter to eliminate the bias noise and Pseudo-photon noise. Based on Bayesian estimation on multi-imaging, an optimal detection rule is found came with minimum error cost. Experimentally demonstration here indicates that performance of double-threshold filter strategy improves the photon detection accuracy than usual integrate method.
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