Low-Cost SPAD Sensing for Non-Line-Of-Sight Tracking, Material Classification and Depth Imaging

Clara Callenberg, Zheng Shi, Felix Heide und Matthias B. Hullin
In: ACM Trans. Graph. (SIGGRAPH) (2021), 40:4
 

Abstract

Time-correlated imaging is an emerging sensing modality that has been shown to enable promising application scenarios, including lidar ranging, fluorescence lifetime imaging, and even non-line-of-sight sensing. A leading technology for obtaining time-correlated light measurements are singlephoton avalanche diodes (SPADs), which are extremely sensitive and capable of temporal resolution on the order of tens of picoseconds. However, the rare and expensive optical setups used by researchers have so far prohibited these novel sensing techniques from entering the mass market. Fortunately, SPADs also exist in a radically cheaper and more power-efficient version that has been widely deployed as proximity sensors in mobile devices for almost a decade. These commodity SPAD sensors can be obtained at a mere few cents per detector pixel. However, their inferior data quality and severe technical drawbacks compared to their high-end counterparts necessitate the use of additional optics and suitable processing algorithms. In this paper, we adopt an existing evaluation platform for commodity SPAD sensors, and modify it to unlock time-of-flight (ToF) histogramming and hence computational imaging. Based on this platform, we develop and demonstrate a family of hardware/software systems that, for the first time, implement applications that had so far been limited to significantly more advanced, higher-priced setups: direct ToF depth imaging, non-line-of-sight object tracking, and material classification.

Bibtex

@ARTICLE{Callenberg2021CheapSPAD,
    author = {Callenberg, Clara and Shi, Zheng and Heide, Felix and Hullin, Matthias B.},
     title = {Low-Cost SPAD Sensing for Non-Line-Of-Sight Tracking, Material Classification and Depth Imaging},
   journal = {ACM Trans. Graph. (SIGGRAPH)},
    volume = {40},
    number = {4},
      year = {2021},
  abstract = {Time-correlated imaging is an emerging sensing modality that has been shown to enable promising
              application scenarios, including lidar ranging, fluorescence lifetime imaging, and even
              non-line-of-sight sensing. A leading technology for obtaining time-correlated light measurements are
              singlephoton avalanche diodes (SPADs), which are extremely sensitive and capable of temporal
              resolution on the order of tens of picoseconds. However, the rare and expensive optical setups used
              by researchers have so far prohibited these novel sensing techniques from entering the mass market.
              Fortunately, SPADs also exist in a radically cheaper and more power-efficient version that has been
              widely deployed as proximity sensors in mobile devices for almost a decade. These commodity SPAD
              sensors can be obtained at a mere few cents per detector pixel. However, their inferior data quality
              and severe technical drawbacks compared to their high-end counterparts necessitate the use of
              additional optics and suitable processing algorithms. In this paper, we adopt an existing evaluation
              platform for commodity SPAD sensors, and modify it to unlock time-of-flight (ToF) histogramming and
              hence computational imaging. Based on this platform, we develop and demonstrate a family of
              hardware/software systems that, for the first time, implement applications that had so far been
              limited to significantly more advanced, higher-priced setups: direct ToF depth imaging,
              non-line-of-sight object tracking, and material classification.}
}