Chao Jerry, Sally Ward E, Ober Raimund J
J Opt Soc Am A Opt Image Sci Vis. 2016 Jul 1;33(7):B36-57. doi: 10.1364/JOSAA.33.000B36.
Estimation of a parameter of interest from image data represents a task that is commonly carried out in single molecule microscopy data analysis. The determination of the positional coordinates of a molecule from its image, for example, forms the basis of standard applications such as single molecule tracking and localization-based super-resolution image reconstruction. Assuming that the estimator used recovers, on average, the true value of the parameter, its accuracy, or standard deviation, is then at best equal to the square root of the Cramér-Rao lower bound. The Cramér-Rao lower bound can therefore be used as a benchmark in the evaluation of the accuracy of an estimator. Additionally, as its value can be computed and assessed for different experimental settings, it is useful as an experimental design tool. This tutorial demonstrates a mathematical framework that has been specifically developed to calculate the Cramér-Rao lower bound for estimation problems in single molecule microscopy and, more broadly, fluorescence microscopy. The material includes a presentation of the photon detection process that underlies all image data, various image data models that describe images acquired with different detector types, and Fisher information expressions that are necessary for the calculation of the lower bound. Throughout the tutorial, examples involving concrete estimation problems are used to illustrate the effects of various factors on the accuracy of parameter estimation and, more generally, to demonstrate the flexibility of the mathematical framework.
从图像数据中估计感兴趣的参数是单分子显微镜数据分析中常见的任务。例如,从分子图像确定其位置坐标是单分子追踪和基于定位的超分辨率图像重建等标准应用的基础。假设所使用的估计器平均能恢复参数的真实值,那么其精度(即标准差)至多等于克拉美 - 罗下界的平方根。因此,克拉美 - 罗下界可作为评估估计器精度的基准。此外,由于其值可针对不同实验设置进行计算和评估,它还是一种有用的实验设计工具。本教程展示了一个专门开发的数学框架,用于计算单分子显微镜以及更广泛的荧光显微镜中估计问题的克拉美 - 罗下界。内容包括构成所有图像数据基础的光子检测过程介绍、描述使用不同探测器类型获取的图像的各种图像数据模型,以及计算下界所需的费希尔信息表达式。在整个教程中,涉及具体估计问题的示例用于说明各种因素对参数估计精度的影响,更广泛地说,是为了展示数学框架的灵活性。