# High Flux Passive Imaging with Single-Photon Sensors

arXiv: https://arxiv.org/abs/1902.10190 · HTML: https://mlsanity.com/paper/1902.10190/

## Key facts

- Cited by 23 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 26 Feb 2019.

## Built on by (most cited first, 23 of 23)

- [Passive Inter-Photon Imaging](https://mlsanity.com/paper/2104.00059/) (2021)
- [Progressive Joint Low-light Enhancement and Noise Removal for Raw Images](https://mlsanity.com/paper/2106.14844/) (2021)
- [MantissaCam: Learning Snapshot High-dynamic-range Imaging with Perceptually-based In-pixel Irradiance Encoding](https://mlsanity.com/paper/2112.05221/) (2021)
- [SoDaCam: Software-defined Cameras via Single-Photon Imaging](https://mlsanity.com/paper/2309.00066/) (2023)
- [Photon-Starved Scene Inference using Single Photon Cameras](https://mlsanity.com/paper/2107.11001/) (2021)
- [Single-Photon Structured Light](https://mlsanity.com/paper/2204.05300/) (2022)
- [HDR Imaging with Spatially Varying Signal-to-Noise Ratios](https://mlsanity.com/paper/2303.17253/) (2023)
- [Adaptive Gating for Single-Photon 3D Imaging](https://mlsanity.com/paper/2111.15047/) (2021)
- [Generalized Event Cameras](https://mlsanity.com/paper/2407.02683/) (2024)
- [Time-Resolved MNIST Dataset for Single-Photon Recognition](https://mlsanity.com/paper/2410.16744/) (2024)
- [Streaming quanta sensors for online, high-performance imaging and vision](https://mlsanity.com/paper/2406.00859/) (2024)
- [Radiance Fields from Photons](https://mlsanity.com/paper/2407.09386/) (2024)
- [Panoramas from Photons](https://mlsanity.com/paper/2309.03811/) (2023)
- [Generative Quanta Color Imaging](https://mlsanity.com/paper/2403.19066/) (2024)
- [Photon Inhibition for Energy-Efficient Single-Photon Imaging](https://mlsanity.com/paper/2409.18337/) (2024)
- [SPC to 3D: Novel View Synthesis from Binary SPC via I2I translation](https://mlsanity.com/paper/2506.06890/) (2025)
- [Dynamic Watermark Generation for Digital Images using Perimeter Gated SPAD Imager PUFs](https://mlsanity.com/paper/2506.17134/) (2025)
- [PhotonSplat: 3D Scene Reconstruction and Colorization from SPAD Sensors](https://mlsanity.com/paper/2506.21680/) (2025)
- [3D Reconstruction from Transient Measurements with Time-Resolved Transformer](https://mlsanity.com/paper/2510.09205/) (2025)
- [Fundamental Recovery Bounds for SPAD Signals under Stationary Flux](https://mlsanity.com/paper/2601.07599/) (2026)
- [Accurate Simulation Pipeline for Passive Single-Photon Imaging](https://mlsanity.com/paper/2601.12850/) (2026)
- [gQIR: Generative Quanta Image Reconstruction](https://mlsanity.com/paper/2602.20417/) (2026)
- [High-Flux Count-Free Single-Photon 3D Cameras](https://mlsanity.com/paper/2608.18306/) (2026)

## Abstract (arXiv)

Single-photon avalanche diodes (SPADs) are an emerging technology with a unique capability of capturing individual photons with high timing precision. SPADs are being used in several active imaging systems (e.g., fluorescence lifetime microscopy and LiDAR), albeit mostly limited to low photon flux settings. We propose passive free-running SPAD (PF-SPAD) imaging, an imaging modality that uses SPADs for capturing 2D intensity images with unprecedented dynamic range under ambient lighting, without any active light source. Our key observation is that the precise inter-photon timing measured by a SPAD can be used for estimating scene brightness under ambient lighting conditions, even for very bright scenes. We develop a theoretical model for PF-SPAD imaging, and derive a scene brightness estimator based on the average time of darkness between successive photons detected by a PF-SPAD pixel. Our key insight is that due to the stochastic nature of photon arrivals, this estimator does not suffer from a hard saturation limit. Coupled with high sensitivity at low flux, this enables a PF-SPAD pixel to measure a wide range of scene brightness, from very low to very high, thereby achieving extreme dynamic range. We demonstrate an improvement of over 2 orders of magnitude over conventional sensors by imaging scenes spanning a dynamic range of 1,000,000:1.