Time-resolved single photon imaging is a promising imaging modality characterized by the unique capability of timestamping the arrivals of single photons. Single-Photon Avalanche Diodes (SPADs) are the leading technology for implementing modern time-resolved pixels, suitable for passive imaging with asynchronous readout. However, they are currently limited to small sized arrays, thus there is a lack of datasets for passive time-resolved SPAD imaging, which in turn hinders research on this peculiar imaging data. In this paper we describe a realistic simulation process for SPAD imaging, which takes into account both the stochastic nature of photon arrivals and all the noise sources involved in the acquisition process of time-resolved SPAD arrays. We have implemented this simulator in a software prototype able to generate arbitrary-sized time-resolved SPAD arrays operating in passive mode. Starting from a reference image, our simulator generates a realistic stream of timestamped photon detections. We use our simulator to generate a time-resolved version of MNIST, which we make publicly available. Our dataset has the purpose of encouraging novel research directions in time-resolved SPAD imaging, as well as investigating the performance of CNN classifiers in extremely low-light conditions.

翻译：时间分辨单光子成像是一种具有前景的成像模式，其独特能力在于能够为单个光子的到达时间打上时间戳。单光子雪崩二极管（SPADs）是实现现代时间分辨像素的主流技术，适用于具有异步读出功能的被动成像。然而，目前该技术仅限于小规模阵列，因此缺乏针对被动时间分辨SPAD成像的数据集，这反过来阻碍了对这类特殊成像数据的研究。本文描述了一种SPAD成像的真实仿真流程，该流程同时考虑了光子到达的随机性以及时间分辨SPAD阵列采集过程中涉及的所有噪声源。我们已在一个软件原型中实现了该仿真器，能够生成任意尺寸、工作在被动模式下的时间分辨SPAD阵列。我们的仿真器从参考图像出发，生成真实的时间戳光子探测流。我们利用该仿真器生成了时间分辨版本的MNIST数据集，并已公开提供。本数据集旨在推动时间分辨SPAD成像领域的新研究方向，并探究CNN分类器在极低光照条件下的性能。