Coded Strobing Photography: Compressive Sensing of High Speed Periodic Videos

—We show that, via temporal modulation, one can observe and capture a high-speed periodic video well beyond the abilities of a low-frame-rate camera. By strobing the exposure with unique sequences within the integration time of each frame, we take coded projections of dynamic events. From a sequence of such frames, we reconstruct a high-speed video of the high-frequency periodic process. Strobing is used in entertainment, medical imaging, and industrial inspection to generate lower beat frequencies. But this is limited to scenes with a detectable single dominant frequency and requires high-intensity lighting. In this paper, we address the problem of sub-Nyquist sampling of periodic signals and show designs to capture and reconstruct such signals. The key result is that for such signals, the Nyquist rate constraint can be imposed on the strobe rate rather than the sensor rate. The technique is based on intentional aliasing of the frequency components of the periodic signal while the r...

• Type: Journal
• Year: 2011
• Where: PAMI
• Authors: Ashok Veeraraghavan, Dikpal Reddy, Ramesh Raskar
• Keywords: Compressive Sensing, Operations Research, PAMI 2011, Periodic Signals, Single Dominant Frequency