Abstract
Event cameras record luminance changes with microsecond resolution, but converting their sparse, asynchronous output into dense tensors that neural networks can exploit remains a core challenge. Conventional histograms or globally-decayed time-surface representations apply fixed temporal parameters across the entire image plane, which in practice creates a trade-off between preserving spatial structure during still periods and retaining sharp edges during rapid motion. We introduce Locally Adaptive Decay Surfaces (LADS), a family of event representations in which the temporal decay at each location is modulated according to local signal dynamics. Three strategies are explored, based on event rate, Laplacian-of-Gaussian response, and high-frequency spectral energy. These adaptive schemes preserve detail in quiescent regions while reducing blur in regions of dense activity. Extensive experiments on the public data show that LADS consistently improves both face detection and facial landmark accuracy compared to standard non-adaptive representations. At 30 Hz, LADS achieves higher detection accuracy and lower landmark error than either baseline, and at 240 Hz it mitigates the accuracy decline typically observed at higher frequencies, sustaining 2.44 % normalized mean error for landmarks and 0.966 mAP50 in face detection. These high-frequency results even surpass the accuracy reported in prior works operating at 30 Hz, setting new benchmarks for event-based face analysis. Moreover, by preserving spatial structure at the representation stage, LADS supports the use of much lighter network architectures while still retaining real-time performance. These results highlight the importance of context-aware temporal integration for neuromorphic vision and point toward real-time, high-frequency human-computer interaction systems that exploit the unique advantages of event cameras.
Abstract (translated)
事件相机以微秒级分辨率记录亮度变化，但将这些稀疏、异步的输出转换成神经网络可以利用的密集张量仍然是一个核心挑战。传统的直方图或全局衰减时间表面表示方法在整个图像平面上应用固定的时序参数，在实践中造成了在静止期间保持空间结构与快速运动区域保留锐利边缘之间的权衡。我们引入了局部自适应衰减表面（LADS），这是一个事件表示家族，其中每个位置的时序衰减根据本地信号动态进行调节。三种策略被探索，分别基于事件速率、高斯拉普拉斯响应和高频频谱能量。这些自适应方案在静止区域保留细节的同时减少了密集活动区域的模糊度。公开数据集上的广泛实验表明，LADS与标准非自适应表示相比，在面部检测和面部标志准确性方面均有所提升。在30 Hz下，LADS实现了更高的检测准确性和更低的地标误差，而在240 Hz时则缓解了高频操作通常观察到的精度下降问题，维持了2.44%的标准化平均错误率用于地标识别以及0.966 mAP50用于面部检测。这些高频结果甚至超过了先前在30 Hz运行的工作所报告的准确性，在基于事件的脸部分析中建立了新的基准。此外，通过在表示阶段保留空间结构，LADS支持使用更轻量级的网络架构同时保持实时性能。这些结果突显了神经形态视觉中上下文感知时序整合的重要性，并指向能够利用事件相机独特优势的实时高频人机交互系统的未来方向。
URL
https://arxiv.org/abs/2602.23101
