The Experts below are selected from a list of 126060 Experts worldwide ranked by ideXlab platform
Andreas Velten - One of the best experts on this subject based on the ideXlab platform.
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Non-Line-of-Sight imaging
Nature Reviews Physics, 2020Co-Authors: Daniele Faccio, Andreas Velten, Gordon WetzsteinAbstract:Non-Line-of-Sight (NLOS) imaging methods use light scattered from multiple surfaces to reconstruct images of scenes that are hidden by another object. This Perspective summarizes existing NLOS imaging techniques and discusses which directions show most promise for future developments. Emerging single-photon-sensitive sensors produce picosecond-accurate time-stamped photon counts. Applying advanced inverse methods to process these data has resulted in unprecedented imaging capabilities, such as non-Line-of-Sight (NLOS) imaging. Rather than imaging photons that travel along direct paths from a source to an object and back to the detector, NLOS methods analyse photons that travel along indirect light paths, scattered from multiple surfaces, to estimate 3D images of scenes outside the direct Line of Sight of a camera, hidden by a wall or other obstacles. We review the transient imaging techniques that underlie many NLOS imaging approaches, discuss methods for reconstructing hidden scenes from time-resolved measurements, describe some other methods for NLOS imaging that do not require transient imaging and discuss the future of ‘seeing around corners’.
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non Line of Sight imaging
arXiv: Optics, 2020Co-Authors: Daniele Faccio, Andreas Velten, Gordon WetzsteinAbstract:Emerging single-photon-sensitive sensors combined with advanced inverse methods to process picosecond-accurate time-stamped photon counts have given rise to unprecedented imaging capabilities. Rather than imaging photons that travel along direct paths from a source to an object and back to the detector, non-Line-of-Sight (NLOS) imaging approaches analyse photons {scattered from multiple surfaces that travel} along indirect light paths to estimate 3D images of scenes outside the direct Line of Sight of a camera, hidden by a wall or other obstacles. Here we review recent advances in the field of NLOS imaging, discussing how to see around corners and future prospects for the field.
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Non-Line-of-Sight imaging using phasor-field virtual wave optics
Nature, 2019Co-Authors: Ibón Guillén, Adrian Jarabo, Marco La Manna, Syed Azer Reza, Diego Gutierrez, Andreas VeltenAbstract:Algorithms based on diffractive wave propagation of light offer effective imaging of complex scenes hidden from direct view. Non-Line-of-Sight imaging allows objects to be observed when partially or fully occluded from direct view, by analysing indirect diffuse reflections off a secondary relay surface. Despite many potential applications^ 1 – 9 , existing methods lack practical usability because of limitations including the assumption of single scattering only, ideal diffuse reflectance and lack of occlusions within the hidden scene. By contrast, Line-of-Sight imaging systems do not impose any assumptions about the imaged scene, despite relying on the mathematically simple processes of Linear diffractive wave propagation. Here we show that the problem of non-Line-of-Sight imaging can also be formulated as one of diffractive wave propagation, by introducing a virtual wave field that we term the phasor field. Non-Line-of-Sight scenes can be imaged from raw time-of-flight data by applying the mathematical operators that model wave propagation in a conventional Line-of-Sight imaging system. Our method yields a new class of imaging algorithms that mimic the capabilities of Line-of-Sight cameras. To demonstrate our technique, we derive three imaging algorithms, modelled after three different Line-of-Sight systems. These algorithms rely on solving a wave diffraction integral, namely the Rayleigh–Sommerfeld diffraction integral. Fast solutions to Rayleigh–Sommerfeld diffraction and its approximations are readily available, benefiting our method. We demonstrate non-Line-of-Sight imaging of complex scenes with strong multiple scattering and ambient light, arbitrary materials, large depth range and occlusions. Our method handles these challenging cases without explicitly inverting a light-transport model. We believe that our approach will help to unlock the potential of non-Line-of-Sight imaging and promote the development of relevant applications not restricted to laboratory conditions.
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Non-Line-of-Sight imaging using phasor-field virtual wave optics
Nature, 2019Co-Authors: Xiaochun Liu, Ibón Guillén, Ji Hyun Nam, Toan Huu Le, Adrian Jarabo, Marco La Manna, Syed Azer Reza, Diego Gutierrez, Andreas VeltenAbstract:Non-Line-of-Sight imaging allows objects to be observed when partially or fully occluded from direct view, by analysing indirect diffuse reflections off a secondary relay surface. Despite many potential applications1–9, existing methods lack practical usability because of limitations including the assumption of single scattering only, ideal diffuse reflectance and lack of occlusions within the hidden scene. By contrast, Line-of-Sight imaging systems do not impose any assumptions about the imaged scene, despite relying on the mathematically simple processes of Linear diffractive wave propagation. Here we show that the problem of non-Line-of-Sight imaging can also be formulated as one of diffractive wave propagation, by introducing a virtual wave field that we term the phasor field. Non-Line-of-Sight scenes can be imaged from raw time-of-flight data by applying the mathematical operators that model wave propagation in a conventional Line-of-Sight imaging system. Our method yields a new class of imaging algorithms that mimic the capabilities of Line-of-Sight cameras. To demonstrate our technique, we derive three imaging algorithms, modelled after three different Line-of-Sight systems. These algorithms rely on solving a wave diffraction integral, namely the Rayleigh–Sommerfeld diffraction integral. Fast solutions to Rayleigh–Sommerfeld diffraction and its approximations are readily available, benefiting our method. We demonstrate non-Line-of-Sight imaging of complex scenes with strong multiple scattering and ambient light, arbitrary materials, large depth range and occlusions. Our method handles these challenging cases without explicitly inverting a light-transport model. We believe that our approach will help to unlock the potential of non-Line-of-Sight imaging and promote the development of relevant applications not restricted to laboratory conditions.
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Non-Line-of-Sight imaging using a time-gated single photon avalanche diode
Optics Express, 2015Co-Authors: Mauro Buttafava, Jessica Zeman, Kevin Eliceiri, Kevin W. Eliceiri, Alberto Tosi, Andreas VeltenAbstract:By using time-of-flight information encoded in multiply scattered light, it is possible to reconstruct images of objects hidden from the camera’s direct Line of Sight. Here, we present a non-Line-of-Sight imaging system that uses a single-pixel, single-photon avalanche diode (SPAD) to collect time-of-flight information. Compared to earlier systems, this modification provides significant improvements in terms of power requirements, form factor, cost, and reconstruction time, while maintaining a comparable time resolution. The potential for further size and cost reduction of this technology make this system a good base for developing a practical system that can be used in real world applications.
Masamune Oguri - One of the best experts on this subject based on the ideXlab platform.
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Line of Sight structure toward strong lensing galaxy clusters
The Astrophysical Journal, 2014Co-Authors: M Bayliss, Traci L Johnson, M D Gladders, Keren Sharon, Masamune OguriAbstract:We present an analysis of the Line-of-Sight structure toward a sample of 10 strong lensing cluster cores. Structure is traced by groups that are identified spectroscopically in the redshift range, 0.1 ≤ z ≤ 0.9, and we measure the projected angular and comoving separations between each group and the primary strong lensing clusters in each corresponding Line of Sight. From these data we measure the distribution of projected angular separations between the primary strong lensing clusters and uncorrelated large-scale structure as traced by groups. We then compare the observed distribution of angular separations for our strong lensing selected Lines of Sight against the distribution of groups that is predicted for clusters lying along random Lines of Sight. There is clear evidence for an excess of structure along the Line of Sight at small angular separations (θ ≤ 6') along the strong lensing selected Lines of Sight, indicating that uncorrelated structure is a significant systematic that contributes to producing galaxy clusters with large cross sections for strong lensing. The prevalence of Line-of-Sight structure is one of several biases in strong lensing clusters that can potentially be folded into cosmological measurements using galaxy cluster samples. These results also have implications for currentmore » and future studies—such as the Hubble Space Telescope Frontier Fields—that make use of massive galaxy cluster lenses as precision cosmological telescopes; it is essential that the contribution of Line-of-Sight structure be carefully accounted for in the strong lens modeling of the cluster lenses.« less
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Line of Sight structure toward strong lensing galaxy clusters
arXiv: Cosmology and Nongalactic Astrophysics, 2013Co-Authors: M Bayliss, Traci L Johnson, M D Gladders, Keren Sharon, Masamune OguriAbstract:We present an analysis of the Line-of-Sight structure toward a sample of ten strong lensing cluster cores. Structure is traced by groups that are identified spectroscopically in the redshift range, 0.1 $\leq$ z $\leq$ 0.9, and we measure the projected angular and comoving separations between each group and the primary strong lensing clusters in each corresponding Line of Sight. From these data we measure the distribution of projected angular separations between the primary strong lensing clusters and uncorrelated large scale structure as traced by groups. We then compare the observed distribution of angular separations for our strong lensing selected Lines of Sight against the distribution of groups that is predicted for clusters lying along random Lines of Sight. There is clear evidence for an excess of structure along the Line of Sight at small angular separations ($\theta \leq 6'$) along the strong lensing selected Lines of Sight, indicating that uncorrelated structure is a significant systematic that contributes to producing galaxy clusters with large cross sections for strong lensing. The prevalence of Line-of-Sight structure is one of several biases in strong lensing clusters that can potentially be folded into cosmological measurements using galaxy cluster samples. These results also have implications for current and future studies -- such as the Hubble Space Telescope Frontier Fields -- that make use of massive galaxy cluster lenses as precision cosmological telescopes; it is essential that the contribution of Line-of-Sight structure be carefully accounted for in the strong lens modeling of the cluster lenses.
Adrian Jarabo - One of the best experts on this subject based on the ideXlab platform.
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Non-Line-of-Sight imaging using phasor-field virtual wave optics
Nature, 2019Co-Authors: Ibón Guillén, Adrian Jarabo, Marco La Manna, Syed Azer Reza, Diego Gutierrez, Andreas VeltenAbstract:Algorithms based on diffractive wave propagation of light offer effective imaging of complex scenes hidden from direct view. Non-Line-of-Sight imaging allows objects to be observed when partially or fully occluded from direct view, by analysing indirect diffuse reflections off a secondary relay surface. Despite many potential applications^ 1 – 9 , existing methods lack practical usability because of limitations including the assumption of single scattering only, ideal diffuse reflectance and lack of occlusions within the hidden scene. By contrast, Line-of-Sight imaging systems do not impose any assumptions about the imaged scene, despite relying on the mathematically simple processes of Linear diffractive wave propagation. Here we show that the problem of non-Line-of-Sight imaging can also be formulated as one of diffractive wave propagation, by introducing a virtual wave field that we term the phasor field. Non-Line-of-Sight scenes can be imaged from raw time-of-flight data by applying the mathematical operators that model wave propagation in a conventional Line-of-Sight imaging system. Our method yields a new class of imaging algorithms that mimic the capabilities of Line-of-Sight cameras. To demonstrate our technique, we derive three imaging algorithms, modelled after three different Line-of-Sight systems. These algorithms rely on solving a wave diffraction integral, namely the Rayleigh–Sommerfeld diffraction integral. Fast solutions to Rayleigh–Sommerfeld diffraction and its approximations are readily available, benefiting our method. We demonstrate non-Line-of-Sight imaging of complex scenes with strong multiple scattering and ambient light, arbitrary materials, large depth range and occlusions. Our method handles these challenging cases without explicitly inverting a light-transport model. We believe that our approach will help to unlock the potential of non-Line-of-Sight imaging and promote the development of relevant applications not restricted to laboratory conditions.
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Non-Line-of-Sight imaging using phasor-field virtual wave optics
Nature, 2019Co-Authors: Xiaochun Liu, Ibón Guillén, Ji Hyun Nam, Toan Huu Le, Adrian Jarabo, Marco La Manna, Syed Azer Reza, Diego Gutierrez, Andreas VeltenAbstract:Non-Line-of-Sight imaging allows objects to be observed when partially or fully occluded from direct view, by analysing indirect diffuse reflections off a secondary relay surface. Despite many potential applications1–9, existing methods lack practical usability because of limitations including the assumption of single scattering only, ideal diffuse reflectance and lack of occlusions within the hidden scene. By contrast, Line-of-Sight imaging systems do not impose any assumptions about the imaged scene, despite relying on the mathematically simple processes of Linear diffractive wave propagation. Here we show that the problem of non-Line-of-Sight imaging can also be formulated as one of diffractive wave propagation, by introducing a virtual wave field that we term the phasor field. Non-Line-of-Sight scenes can be imaged from raw time-of-flight data by applying the mathematical operators that model wave propagation in a conventional Line-of-Sight imaging system. Our method yields a new class of imaging algorithms that mimic the capabilities of Line-of-Sight cameras. To demonstrate our technique, we derive three imaging algorithms, modelled after three different Line-of-Sight systems. These algorithms rely on solving a wave diffraction integral, namely the Rayleigh–Sommerfeld diffraction integral. Fast solutions to Rayleigh–Sommerfeld diffraction and its approximations are readily available, benefiting our method. We demonstrate non-Line-of-Sight imaging of complex scenes with strong multiple scattering and ambient light, arbitrary materials, large depth range and occlusions. Our method handles these challenging cases without explicitly inverting a light-transport model. We believe that our approach will help to unlock the potential of non-Line-of-Sight imaging and promote the development of relevant applications not restricted to laboratory conditions.
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fast back projection for non Line of Sight reconstruction
International Conference on Computer Graphics and Interactive Techniques, 2017Co-Authors: Victor Arellano, Diego Gutierrez, Adrian JaraboAbstract:Recent works have demonstrated non-Line of Sight (NLOS) reconstruction by using the time-resolved signal from multiply scattered light. These works combine ultrafast imaging systems with computation, which back-projects the recorded space-time signal to build a probabilistic map of the hidden geometry. Unfortunately, this computation is slow, becoming a bottleneck as the imaging technology improves. In this work, we propose a new back-projection technique for NLOS reconstruction, which is up to a thousand times faster than previous work, with negligible quality loss.
Diego Gutierrez - One of the best experts on this subject based on the ideXlab platform.
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Non-Line-of-Sight imaging using phasor-field virtual wave optics
Nature, 2019Co-Authors: Ibón Guillén, Adrian Jarabo, Marco La Manna, Syed Azer Reza, Diego Gutierrez, Andreas VeltenAbstract:Algorithms based on diffractive wave propagation of light offer effective imaging of complex scenes hidden from direct view. Non-Line-of-Sight imaging allows objects to be observed when partially or fully occluded from direct view, by analysing indirect diffuse reflections off a secondary relay surface. Despite many potential applications^ 1 – 9 , existing methods lack practical usability because of limitations including the assumption of single scattering only, ideal diffuse reflectance and lack of occlusions within the hidden scene. By contrast, Line-of-Sight imaging systems do not impose any assumptions about the imaged scene, despite relying on the mathematically simple processes of Linear diffractive wave propagation. Here we show that the problem of non-Line-of-Sight imaging can also be formulated as one of diffractive wave propagation, by introducing a virtual wave field that we term the phasor field. Non-Line-of-Sight scenes can be imaged from raw time-of-flight data by applying the mathematical operators that model wave propagation in a conventional Line-of-Sight imaging system. Our method yields a new class of imaging algorithms that mimic the capabilities of Line-of-Sight cameras. To demonstrate our technique, we derive three imaging algorithms, modelled after three different Line-of-Sight systems. These algorithms rely on solving a wave diffraction integral, namely the Rayleigh–Sommerfeld diffraction integral. Fast solutions to Rayleigh–Sommerfeld diffraction and its approximations are readily available, benefiting our method. We demonstrate non-Line-of-Sight imaging of complex scenes with strong multiple scattering and ambient light, arbitrary materials, large depth range and occlusions. Our method handles these challenging cases without explicitly inverting a light-transport model. We believe that our approach will help to unlock the potential of non-Line-of-Sight imaging and promote the development of relevant applications not restricted to laboratory conditions.
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Non-Line-of-Sight imaging using phasor-field virtual wave optics
Nature, 2019Co-Authors: Xiaochun Liu, Ibón Guillén, Ji Hyun Nam, Toan Huu Le, Adrian Jarabo, Marco La Manna, Syed Azer Reza, Diego Gutierrez, Andreas VeltenAbstract:Non-Line-of-Sight imaging allows objects to be observed when partially or fully occluded from direct view, by analysing indirect diffuse reflections off a secondary relay surface. Despite many potential applications1–9, existing methods lack practical usability because of limitations including the assumption of single scattering only, ideal diffuse reflectance and lack of occlusions within the hidden scene. By contrast, Line-of-Sight imaging systems do not impose any assumptions about the imaged scene, despite relying on the mathematically simple processes of Linear diffractive wave propagation. Here we show that the problem of non-Line-of-Sight imaging can also be formulated as one of diffractive wave propagation, by introducing a virtual wave field that we term the phasor field. Non-Line-of-Sight scenes can be imaged from raw time-of-flight data by applying the mathematical operators that model wave propagation in a conventional Line-of-Sight imaging system. Our method yields a new class of imaging algorithms that mimic the capabilities of Line-of-Sight cameras. To demonstrate our technique, we derive three imaging algorithms, modelled after three different Line-of-Sight systems. These algorithms rely on solving a wave diffraction integral, namely the Rayleigh–Sommerfeld diffraction integral. Fast solutions to Rayleigh–Sommerfeld diffraction and its approximations are readily available, benefiting our method. We demonstrate non-Line-of-Sight imaging of complex scenes with strong multiple scattering and ambient light, arbitrary materials, large depth range and occlusions. Our method handles these challenging cases without explicitly inverting a light-transport model. We believe that our approach will help to unlock the potential of non-Line-of-Sight imaging and promote the development of relevant applications not restricted to laboratory conditions.
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fast back projection for non Line of Sight reconstruction
International Conference on Computer Graphics and Interactive Techniques, 2017Co-Authors: Victor Arellano, Diego Gutierrez, Adrian JaraboAbstract:Recent works have demonstrated non-Line of Sight (NLOS) reconstruction by using the time-resolved signal from multiply scattered light. These works combine ultrafast imaging systems with computation, which back-projects the recorded space-time signal to build a probabilistic map of the hidden geometry. Unfortunately, this computation is slow, becoming a bottleneck as the imaging technology improves. In this work, we propose a new back-projection technique for NLOS reconstruction, which is up to a thousand times faster than previous work, with negligible quality loss.
Ibón Guillén - One of the best experts on this subject based on the ideXlab platform.
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Non-Line-of-Sight imaging using phasor-field virtual wave optics
Nature, 2019Co-Authors: Ibón Guillén, Adrian Jarabo, Marco La Manna, Syed Azer Reza, Diego Gutierrez, Andreas VeltenAbstract:Algorithms based on diffractive wave propagation of light offer effective imaging of complex scenes hidden from direct view. Non-Line-of-Sight imaging allows objects to be observed when partially or fully occluded from direct view, by analysing indirect diffuse reflections off a secondary relay surface. Despite many potential applications^ 1 – 9 , existing methods lack practical usability because of limitations including the assumption of single scattering only, ideal diffuse reflectance and lack of occlusions within the hidden scene. By contrast, Line-of-Sight imaging systems do not impose any assumptions about the imaged scene, despite relying on the mathematically simple processes of Linear diffractive wave propagation. Here we show that the problem of non-Line-of-Sight imaging can also be formulated as one of diffractive wave propagation, by introducing a virtual wave field that we term the phasor field. Non-Line-of-Sight scenes can be imaged from raw time-of-flight data by applying the mathematical operators that model wave propagation in a conventional Line-of-Sight imaging system. Our method yields a new class of imaging algorithms that mimic the capabilities of Line-of-Sight cameras. To demonstrate our technique, we derive three imaging algorithms, modelled after three different Line-of-Sight systems. These algorithms rely on solving a wave diffraction integral, namely the Rayleigh–Sommerfeld diffraction integral. Fast solutions to Rayleigh–Sommerfeld diffraction and its approximations are readily available, benefiting our method. We demonstrate non-Line-of-Sight imaging of complex scenes with strong multiple scattering and ambient light, arbitrary materials, large depth range and occlusions. Our method handles these challenging cases without explicitly inverting a light-transport model. We believe that our approach will help to unlock the potential of non-Line-of-Sight imaging and promote the development of relevant applications not restricted to laboratory conditions.
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Non-Line-of-Sight imaging using phasor-field virtual wave optics
Nature, 2019Co-Authors: Xiaochun Liu, Ibón Guillén, Ji Hyun Nam, Toan Huu Le, Adrian Jarabo, Marco La Manna, Syed Azer Reza, Diego Gutierrez, Andreas VeltenAbstract:Non-Line-of-Sight imaging allows objects to be observed when partially or fully occluded from direct view, by analysing indirect diffuse reflections off a secondary relay surface. Despite many potential applications1–9, existing methods lack practical usability because of limitations including the assumption of single scattering only, ideal diffuse reflectance and lack of occlusions within the hidden scene. By contrast, Line-of-Sight imaging systems do not impose any assumptions about the imaged scene, despite relying on the mathematically simple processes of Linear diffractive wave propagation. Here we show that the problem of non-Line-of-Sight imaging can also be formulated as one of diffractive wave propagation, by introducing a virtual wave field that we term the phasor field. Non-Line-of-Sight scenes can be imaged from raw time-of-flight data by applying the mathematical operators that model wave propagation in a conventional Line-of-Sight imaging system. Our method yields a new class of imaging algorithms that mimic the capabilities of Line-of-Sight cameras. To demonstrate our technique, we derive three imaging algorithms, modelled after three different Line-of-Sight systems. These algorithms rely on solving a wave diffraction integral, namely the Rayleigh–Sommerfeld diffraction integral. Fast solutions to Rayleigh–Sommerfeld diffraction and its approximations are readily available, benefiting our method. We demonstrate non-Line-of-Sight imaging of complex scenes with strong multiple scattering and ambient light, arbitrary materials, large depth range and occlusions. Our method handles these challenging cases without explicitly inverting a light-transport model. We believe that our approach will help to unlock the potential of non-Line-of-Sight imaging and promote the development of relevant applications not restricted to laboratory conditions.
