Low-latency time-of-flight non-line-of-sight imaging at 5 frames per second

AbstractNon-Line-Of-Sight (NLOS) imaging aims at recovering the 3D geometry of objects that are hidden from the direct line of sight. One major challenge with this technique is the weak available multibounce signal limiting scene size, capture speed, and reconstruction quality. To overcome this obstacle, we introduce a multipixel time-of-flight non-line-of-sight imaging method combining specifically designed Single Photon Avalanche Diode (SPAD) array detectors with a fast reconstruction algorithm that captures and reconstructs live low-latency videos of non-line-of-sight scenes with natural non-retroreflective objects. We develop a model of the signal-to-noise-ratio of non-line-of-sight imaging and use it to devise a method that reconstructs the scene such that signal-to-noise-ratio, motion blur, angular resolution, and depth resolution are all independent of scene depth suggesting that reconstruction of very large scenes may be possible.

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Note: Temperature compensation of time-of-flight light detection and ranging (LiDAR) using feedback control of signal-to-noise ratio of photodetector

Review of Scientific Instruments ◽

10.1063/1.5036568 ◽

2018 ◽

Vol 89 (12) ◽

pp. 126108

Author(s):

Bumsik Won ◽

Junhwan Jang ◽

Sungui Hwang ◽

Kyihwan Park

Keyword(s):

Feedback Control ◽

Temperature Compensation ◽

Signal To Noise Ratio ◽

Time Of Flight ◽

Light Detection And Ranging ◽

Signal To Noise ◽

Light Detection ◽

Noise Ratio

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Signal-to-Noise Ratio and Astronomical Fourier Transform Spectroscopy

Symposium - International Astronomical Union ◽

10.1017/s0074180900034793 ◽

1988 ◽

Vol 132 ◽

pp. 71-78

Author(s):

J. P. Maillard

Keyword(s):

Fourier Transform ◽

Signal To Noise Ratio ◽

Resolving Power ◽

High Resolution Spectroscopy ◽

Signal To Noise ◽

Array Detectors ◽

Noise Ratio ◽

The Fourier Transform ◽

Large Telescopes ◽

Very High

The multiplex properties of the Fourier Transform Spectrometer (FTS) can be considered as disadvantageous with modern detectors and large telescopes, the dominant noise source being no longer in most applications the detector noise. Nevertheless, a FTS offers a gain in information and other instrumental features remain: flexibility in choosing resolving power up to very high values, large throughput, essential in high–resolution spectroscopy with large telescopes, metrologic accuracy, automatic substraction of parasitic background. The signal–to–noise ratio in spectra can also be improved: by limiting the bandwidth with cold filters or even cold dispersers, by matching the instrument to low background foreoptics and high–image quality telescopes. The association with array detectors provides the solution for the FTS to regain its full multiplex advantage.

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On the signal-to-noise ratio of a synthetic aperture ultrasound imaging method

European Journal of Ultrasound ◽

10.1016/0929-8266(95)00160-s ◽

1996 ◽

Vol 3 (3) ◽

pp. 277-281 ◽

Cited By ~ 12

Author(s):

J. Ylitalo

Keyword(s):

Ultrasound Imaging ◽

Signal To Noise Ratio ◽

Synthetic Aperture ◽

Imaging Method ◽

Signal To Noise ◽

Noise Ratio

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Effects of Quantization of Time-of-Flight (TOF) Measurements on Image Signal-to-Noise Ratio in TOF Emission Tomography

IEEE Transactions on Nuclear Science ◽

10.1109/tns.1983.4332364 ◽

1983 ◽

Vol 30 (1) ◽

pp. 720-722 ◽

Cited By ~ 4

Author(s):

David G. Politte ◽

Timothy J. Holmes ◽

Donald L. Snyder

Keyword(s):

Signal To Noise Ratio ◽

Time Of Flight ◽

Emission Tomography ◽

Signal To Noise ◽

Noise Ratio

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Increasing reliability of forensic analysis while research on destroyed relief marking with magneto-optical devices

Theory and Practice of Forensic Science and Criminalistics ◽

10.32353/khrife.1.2021.11 ◽

2021 ◽

Vol 23 (1) ◽

pp. 148-166

Author(s):

Yu. Agalidi ◽

O. Koshel

Keyword(s):

Optical Imaging ◽

Signal To Noise Ratio ◽

Forensic Analysis ◽

Imaging Method ◽

Signal Recognition ◽

Visualization Method ◽

Signal To Noise ◽

Instrumental Data ◽

Noise Ratio ◽

Correct Signal

While research on destroyed relief marking of metal objects using the magneto-optical method, visualization of (invisible) fields of internal stress in the VIN plate area is performed and then a forensic analysis of obtained instrumental data is carried out (indirect organoleptic observation of the visualization results); thus, forensic analysis reliability of results directly depends on sensitivity of instruments and informativeness of instrumental data. The main quantitative characteristic in this case is probability of correct signal recognition (contours of marking signs) against the background of noise (structural noise of investigated surface and the noise of the visualization method itself) determined by the signal-to-noise ratio. This article presents results of a comparative experimental assessment of signal-to-noise ratio and probability of correct signal recognition while restoringthe destroyed relief markings for two complexes of magneto-optical imaging – models of 2006 and 2018. This article purpose is a quantitative and qualitative comparative assessment of results of visualization of internal stresses in areas of completely removed relief marking of metal objects. The results of successful practical research obtained by forensic experts from different countries make it possible to assess effectiveness and prospects of using the magneto-optical imaging method. In a new modification of the magneto-optical complex: signal level is 4.35 dB higher (contrast of reconstructed marking signs); 2.71 dB lower noise level (surface relief/texture and magnetic copying noise);• probability of correct character recognition is P> 0.995 (increased by 14.9%). Technical improvements in implementation of magneto-optical visualization method made it possible to expand the range of materials for research objects(magnetic and electrically conductive materials were investigated). The high efficiency of method for restoring marking is illustrated by results of forensic examinations for materials with a low level of residual stresses (aluminum alloy, low-carbon steel) which chemical etching method did not give results for. The use of new modification allows examining the rust layer, up to cases of corrosion to the entire depth of marks. Considering non-destructive nature of magneto-optical researches, possibility of their repeated repetition without losing object properties, this method (in accordance with the order of application of types of studies) deserves more attention for application.

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