Event-Based Vision: A Survey
Guillermo GallegoTobi DelbruckGarrick OrchardChiara BartolozziBrian TabaAndrea CensiStefan LeuteneggerAndrew DavisonJoerg ConradtKostas Daniilidis
Presents a systematic overview of event-based vision by examining sensor hardware, processing algorithms from optical flow to 3D reconstruction, and neuromorphic computing methods for high-speed, high-dynamic-range perception.
Event cameras represent a fundamental shift from conventional frame-based imaging by asynchronously detecting per-pixel brightness changes and outputting sparse event streams that encode time, location, and polarity. Traditional cameras struggle with high-speed motion, extreme dynamic range, and low-latency requirements common in robotics and wearable systems, while event cameras offer microsecond temporal resolution, 140 dB dynamic range, low power consumption, and minimal motion blur.
The article surveys the emerging field of event-based vision to evaluate the technology's capabilities, document available sensors and processing methods, and identify pathways to practical deployment. It reviews the underlying pixel designs, event generation models, and both model-based and learning-based algorithms across low-level tasks such as feature detection, tracking, and optical flow estimation as well as higher-level tasks including 3D reconstruction, SLAM, motion segmentation, and object recognition.
Key findings show that event cameras can enable robust performance in scenarios where frame cameras fail, that motion-compensation and time-surface representations effectively aggregate sparse events for downstream processing, and that integration with neuromorphic processors and spiking networks yields low-power, low-latency systems. The survey also establishes that image reconstruction from events is feasible under appropriate regularization yet is often unnecessary when tasks are solved directly from the event stream.
These results matter because they demonstrate concrete routes to efficient, high-speed perception for autonomous vehicles, drones, AR/VR, and surveillance without the power or latency penalties of conventional cameras. Adoption could reduce system cost and energy use while expanding operational envelopes in uncontrolled lighting and fast motion.
Next steps include development of standardized benchmarks and larger annotated datasets, refinement of noise models and pixel miniaturization for mass production, and exploration of task-driven sensing that couples perception directly with control. Continued progress on hybrid event-frame pipelines and on-chip learning will further accelerate deployment.
The survey is comprehensive yet limited by the nascent state of the field, with many algorithms evaluated on small or synthetic datasets and hardware still relatively expensive. Confidence is high in the reported advantages and algorithmic trends, with moderate caution advised on quantitative performance claims until larger-scale, standardized evaluations become available.
- Paper: Past, Present, and Future of Simultaneous Localization and Mapping: Toward the Robust-Perception Age, Cesar Cadena et al. (2016). This foundational survey outlines the core principles, state-estimation paradigms, and robustness challenges in visual SLAM that event-based vision systems directly aim to resolve in high-speed and high-dynamic-range settings.
- Paper: FlowNet: Learning Optical Flow with Convolutional Networks, Philipp Fischer et al. (2015). Understanding this foundational work on learning optical flow from synthetic data provides key context for the learning-based motion and flow estimation techniques surveyed in event vision.
- Paper: On Space-Time Interest Points, I. Laptev (2005). This classic paper establishes the mathematical formulation of space-time interest points, which underpins the spatiotemporal feature representation methods used for asynchronous event streams.
- Paper: Efficient Processing of Deep Neural Networks: A Tutorial and Survey, Vivienne Sze et al. (2017). This tutorial details hardware accelerator dataflows and energy-efficiency bottlenecks in neural processing, providing necessary architectural context for deploying low-power event vision pipelines on neuromorphic hardware.
- Paper: Unsupervised Learning of Depth and Ego-Motion from Video, Tinghui Zhou et al. (2017). Reading this paper provides the foundational photometric warping formulation for unsupervised joint learning of depth and camera ego-motion adapted by modern event-based visual odometry methods.
- Paper: An efficient solution to the five-point relative pose problem, D. Nistér (2004). This paper provides the standard 5-point relative pose algorithm that serves as the baseline geometric solver integrated into event-based 3D reconstruction and visual odometry pipelines.
- Paper: 4D Spatio-Temporal ConvNets: Minkowski Convolutional Neural Networks, Christopher Choy et al. (2019). This work introduces 4D Minkowski sparse convolutional networks, providing an efficient spatio-temporal computational engine directly suitable for processing sparse, asynchronous event camera data.
- Paper: RAFT: Recurrent All-Pairs Field Transforms for Optical Flow, Zachary Teed et al. (2020). This work develops the RAFT architecture for recurrent optical flow estimation, representing a major algorithmic paradigm that subsequent event-based motion estimation frameworks adapt and benchmark against.
- Paper: D-NeRF: neural radiance fields for dynamic scenes, Albert Pumarola et al. (2021). This paper extends neural radiance fields to dynamic scenes using continuous temporal deformations, offering a continuous-time 3D reconstruction formulation complementary to high-temporal-resolution event imaging.
