SpinCam: High-Speed Imaging via a Rotating Point-Spread Function

Abstract

High-speed cameras are an indispensable tool used for the slow-motion analysis of scenes. The fixed bandwidth of any imaging system quickly becomes a bottleneck however, resulting in a fundamental trade-off between the camera's spatial and temporal resolutions. In recent years, compressive high-speed imaging systems have been proposed to circumvent these issues, by optically compressing the signal and using a reconstruction procedure to recover a video. In our work, we propose a novel approach for compressive high-speed imaging based on temporally coding the camera's point-spread function (PSF). By mechanically spinning a diffraction grating in front of a camera, the sensor integrates an image blurred by a PSF that continuously rotates over time. We also propose a deconvolution-based reconstruction algorithm to reconstruct videos from these measurements. Our method achieves superior light efficiency and handles a wider class of scenes compared to prior methods. Also, our mechanical design yields flexible temporal resolution that can be easily increased, potentially allowing capture at 192 kHz--far higher than prior works. We demonstrate a prototype on various applications including motion capture and particle image velocimetry (PIV).