Barrett Harrison H, Myers Kyle J, Caucci Luca
College of Optical Sciences, University of Arizona, Tucson AZ 85721; Center for Gamma-Ray Imaging, Dept. of Medical Imaging, Tucson AZ 85724.
Div. of Imaging and Applied Mathematics, Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD 20993.
Proc SPIE Int Soc Opt Eng. 2014 Aug 17;9193. doi: 10.1117/12.2066715. Epub 2014 Sep 12.
A fundamental way of describing a photon-limited imaging system is in terms of a Poisson random process in spatial, angular and wavelength variables. The mean of this random process is the spectral radiance. The principle of conservation of radiance then allows a full characterization of the noise in the image (conditional on viewing a specified object). To elucidate these connections, we first review the definitions and basic properties of radiance as defined in terms of geometrical optics, radiology, physical optics and quantum optics. The propagation and conservation laws for radiance in each of these domains are reviewed. Then we distinguish four categories of imaging detectors that all respond in some way to the incident radiance, including the new category of photon-processing detectors. The relation between the radiance and the statistical properties of the detector output is discussed and related to task-based measures of image quality and the information content of a single detected photon.
描述光子受限成像系统的一种基本方法是从空间、角度和波长变量的泊松随机过程角度进行。这个随机过程的均值就是光谱辐射度。辐射度守恒原理进而能够全面表征图像中的噪声（条件是观察特定物体）。为了阐明这些联系，我们首先回顾一下从几何光学、放射学、物理光学和量子光学角度定义的辐射度的定义和基本特性。接着回顾每个领域中辐射度的传播和守恒定律。然后我们区分四类成像探测器，它们都以某种方式对入射辐射度做出响应，包括新的光子处理探测器类别。讨论了辐射度与探测器输出统计特性之间的关系，并将其与基于任务的图像质量度量以及单个探测光子的信息含量联系起来。
