  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.
