Event-based Visual Vibrometry

Visual vibrometry has emerged as a powerful technique for remote acquisition of audio signals and the physical properties of materials. To capture high-frequency vibrations, frame-based visual vibrometry approaches often require a high-speed video camera and bright lighting to compensate for the short exposure time. In this paper, we introduce event-based visual vibrometry, a new high-speed visual vibration sensing method using an event camera. Exploiting the high temporal resolution, dynamic range, and low bandwidth characteristics of event cameras, event-based visual vibrometry achieves high-speed vibration sensing under common lighting conditions with enhanced data efficiency. Specifically, we leverage a hybrid camera system and propose an event-based subtle motion estimation framework that integrates an optimization-based approach for estimating coarse motion within short time intervals and a neural network to mitigate the inaccuracies in the coarse motion estimation. We demonstrate our method by capturing vibration caused by audio sources and estimating material properties for various objects.