# Video from Stills: Lensless Imaging with Rolling Shutter

## TL;DR

This paper introduces a lensless, diffuser-based imaging system that uses multiplexing optics and compressed sensing to recover high frame rate video from a single rolling shutter image, surpassing traditional methods for sparse scenes.

## Contribution

It presents a novel lensless imaging approach combining multiplexing optics and sparse recovery to achieve high-speed video reconstruction from a single image.

## Key findings

- Recovered 140 frames at over 4,500 fps
- Uses simple, inexpensive diffusers and off-the-shelf sensors
- Outperforms global shutter systems for sparse objects

## Abstract

Because image sensor chips have a finite bandwidth with which to read out pixels, recording video typically requires a trade-off between frame rate and pixel count. Compressed sensing techniques can circumvent this trade-off by assuming that the image is compressible. Here, we propose using multiplexing optics to spatially compress the scene, enabling information about the whole scene to be sampled from a row of sensor pixels, which can be read off quickly via a rolling shutter CMOS sensor. Conveniently, such multiplexing can be achieved with a simple lensless, diffuser-based imaging system. Using sparse recovery methods, we are able to recover 140 video frames at over 4,500 frames per second, all from a single captured image with a rolling shutter sensor. Our proof-of-concept system uses easily-fabricated diffusers paired with an off-the-shelf sensor. The resulting prototype enables compressive encoding of high frame rate video into a single rolling shutter exposure, and exceeds the sampling-limited performance of an equivalent global shutter system for sufficiently sparse objects.