Computational periscopy with an ordinary digital camera

Abstract

Computational periscopy with an ordinary digital camera This work was made openly accessible by BU Faculty. Please share how this access benefits you. Your story matters.Computing the proportions of light arriving from different directions allows a diffusely reflecting surface to play the role of a mirror in a periscope. Such computational periscopy has previously depended on light travel distances being proportional to times of flight and thus has mostly been achieved with expensive, specialized ultrafast optical systems 1-12 . We introduce a 2D computational periscopy technique that requires only a single photograph captured with an ordinary digital camera. Our technique recovers the position of an opaque object and the scene behind (but not completely obscured by) the object, where both the object and scene are outside the line of sight of the camera, without requiring controlled or time-varying illumination. Non-line-of-sight imaging with only inexpensive, ubiquitous equipment may have considerable value in monitoring of hazardous environments, navigation, and detecting hidden adversaries.

Phasor field diffraction based reconstruction for fast non-line-of-sight imaging systems

“…There are also several contributions showing that it is possible to do NLOS imaging without picosecond scale time resolution or with non-optical signals: Inexpensive nanosecond time of flight sensors can be used to recover the hidden scene 33 , tracking can be performed using intensity based NLOS imaging 34 , occlusions are harnessed to recover images around a corner using regular cameras [35][36][37] , even describing the occlusion-aided method as a blind deconvolution problem without knowledge of the occluder 38 . Other approaches decode the hidden object from regular camera images by using a deep neural network trained with simulated data only 39 , or use acoustic 40 or long-wave infrared 41 signals to image around the corner.…”

Direct Object Recognition Without Line-Of-Sight Using Optical Coherence

“…The proposed method requires hardware (mostly consumer-grade electronics) that is far less expensive than that required for the TOF-based NLOS imaging [16,24,25,26,27,33,37,39,40], and the method is more robust than the memoryeffect based imaging techniques that have a limited field-ofview [11,21]. Moreover, a recent publication [31] also uses only ordinal digital cameras but would require very specific scene setup (an accidental occlusion) to obtain better performance.…”

Thermal non-line-of-sight imaging from specular and diffuse reflections

“…Bouman et al [7] showed that obstructions with edges, e.g., walls, can be exploited as a camera that reveals the NLOS scene beyond them. Saunders et al [8] proposed a passive NLOS imaging which requires only a single image captured with an ordinary camera to recover a partially hidden scene and the position of an opaque object in the NLOS scene. Beckus et al [9] also proposed a passive NLOS imaging by a multi-modal fusion of the intensity and the spatial coherence function.…”