Compressive Single-Photon 3D Cameras

Felipe Gutierrez-Barragan, Atul Ingle, Trevor Seets, Mohit Gupta, Andreas Velten

Abstract:

Single-photon avalanche diodes (SPADs) are an emerging pixel technology for time-of-flight (ToF) 3D cameras
that can capture the time-of-arrival of individual photons at
picosecond resolution. To estimate depths, current SPADbased 3D cameras measure the round-trip time of a laser
pulse by building a per-pixel histogram of photon timestamps. As the spatial and timestamp resolution of SPADbased cameras increase, their output data rates far exceed the capacity of existing data transfer technologies.
One major reason for SPAD’s bandwidth-intensive operation is the tight coupling that exists between depth resolution and histogram resolution. To weaken this coupling,
we propose compressive single-photon histograms (CSPH).
CSPHs are a per-pixel compressive representation of the
high-resolution histogram, that is built on-the-fly, as each
photon is detected. They are based on a family of linear
coding schemes that can be expressed as a simple matrix
operation. We design different CSPH coding schemes for
3D imaging and evaluate them under different signal and
background levels, laser waveforms, and illumination setups. Our results show that a well-designed CSPH can consistently reduce data rates by 1-2 orders of magnitude without compromising depth precision.