Prof. Amit Ashok Profile

Prof. Amit Ashok

Professor at Wyant College of Optical Sciences

SPIE Involvement:

Conference Chair | Author | Editor

Area of Expertise:

Image Science , Compressive Sensing , Information Theory , Computational Imaging , Bayesian Inference , Statistical Signal Processing

Websites:

Personal Website | Company Website

Profile Summary

Amit Ashok is a professor with the College of Optical Sciences and the Department of Electrical and Computer Engineering at the University of Arizona. His research focus is in the areas of computational imaging, inverse problems, statistical inference as it relates to image science. He is also interested in adaptation in imaging system design to incorporate active learning techniques to lead to smart imagers and sensors.

Publications (39)

Proceedings Article | 3 October 2023 Presentation + Paper

Presentation + Paper

Optical contrast amplification for enhancing event-based vision

Sebastian Valencia, Joseph Cox, Amit Ashok, Nicholas Morley

Proceedings Volume 12693, 126930Y (2023) https://doi.org/10.1117/12.2678160

KEYWORDS: Object detection, Tunable filters, Contrast sensitivity, Sensors, Light sources and illumination, Spatial frequencies, Spatial filtering, Signal to noise ratio, Image filtering, Spatial coherence, Fourier optics, Image contrast enhancement, Coherent optics

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Proceedings Article | 3 October 2023 Presentation + Paper

Presentation + Paper

Hybrid event and frame-based system for target detection, tracking, and identification

Trevor Schlack, Logan Pawlowski, Amit Ashok

Proceedings Volume 12693, 1269310 (2023) https://doi.org/10.1117/12.2677036

KEYWORDS: Sensors, Object detection, Target detection, Cameras, Detection and tracking algorithms, Temporal resolution, Neural networks, Motion detection, Imaging systems

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Proceedings Article | 3 October 2023 Presentation + Paper

Presentation + Paper

Analysis of event-based sensor system performance with moving object detection tasks

Joseph Cox, Jacob Trzaska, Amit Ashok, Nicholas Morley

Proceedings Volume 12693, 126930W (2023) https://doi.org/10.1117/12.2675770

KEYWORDS: Sensors, Object detection, Imaging systems, Image processing, Image sensors, Detection and tracking algorithms, Clutter, Spatial filtering, Image filtering

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Proceedings Article | 14 June 2023 Presentation + Paper

Presentation + Paper

Classifiers for material discrimination with dual modality x-ray transmission and coherent x-ray diffraction system

R. Thamvichai, Dan Pike, J. Greenberg, A. Ashok

Proceedings Volume 12531, 1253104 (2023) https://doi.org/10.1117/12.2664196

KEYWORDS: X-ray diffraction, X-rays, Classification systems, Palladium, Image segmentation, Diffraction, Data modeling, Reconstruction algorithms, Machine learning, Image restoration

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Proceedings Article | 14 June 2023 Presentation + Paper

Presentation + Paper

Simulation and information-theoretic analysis of hybrid CT+XRD imaging system

Sarah Ruiz, Ava Hurlock, Shu Yang, Mauricio Martinez, Ratchaneekorn Thamvichai, Joel Greenberg, Amit Ashok, Michael Gehm

Proceedings Volume 12531, 125310A (2023) https://doi.org/10.1117/12.2664066

KEYWORDS: Photon counting, Imaging systems, X-ray computed tomography, X-ray diffraction, Computed tomography, Device simulation, Computer simulations, X-ray imaging, Tungsten, Data acquisition

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Proceedings Article | 14 June 2023 Presentation

Presentation

Experimental validation of spatio-spectral regularized x-ray coherent diffraction reconstruction

Amit Ashok, Shu Yang, Joel Greenberg

Proceedings Volume 12531, 1253107 (2023) https://doi.org/10.1117/12.2664384

KEYWORDS: X-rays, X-ray diffraction, Diffraction, X-ray imaging, X-ray detectors, Tomography, Sensors, Scatter measurement, Modulation, Imaging systems

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Proceedings Article | 13 June 2022 Presentation

Presentation

Machine learning based threat detection for dual modality X-ray transmission and coherent diffraction security screening systems

Thamvichai Ratchaneekorn, Amit Ashok

Proceedings Volume PC12104, PC1210404 (2022) https://doi.org/10.1117/12.2618903

KEYWORDS: X-rays, X-ray diffraction, Diffraction, Information security, Machine learning, Palladium, X-ray detectors

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Proceedings Article | 12 April 2021 Paper

Paper

Design and analysis of a hybrid x-ray transmission and diffraction system

Joel Greenberg, Josh Carpenter, David Coccarelli, Yijun Ding, Shu Yang, Emily Fang, Kris Brumbaugh, Christopher Gregory, Amit Ashok, Anuj Kapadia, Michael Gehm

Proceedings Volume 11738, 1173807 (2021) https://doi.org/10.1117/12.2585640

KEYWORDS: Diffraction, X-rays, X-ray diffraction, Imaging systems, Medical diagnostics, Inspection, Information security, Explosives detection, Explosives

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Proceedings Article | 20 August 2020 Presentation + Paper

Presentation + Paper

An analysis framework for event-based sensor performance

Joseph Cox, Amit Ashok, Nicholas Morley

Proceedings Volume 11508, 115080R (2020) https://doi.org/10.1117/12.2567620

KEYWORDS: Target detection, Imaging systems, Cameras, Sensors, Analytical research, Performance modeling, Machine vision, Electro optics, Computer vision technology

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Proceedings Article | 1 June 2020 Paper

Paper

X-ray measurement model and information-theoretic metric incorporating material variability with spatial and energy correlations

Yijun Ding, Amit Ashok

Proceedings Volume 11404, 114040G (2020) https://doi.org/10.1117/12.2557924

KEYWORDS: X-rays, Systems modeling, Sensors, Photons, Data modeling, Performance modeling, X-ray imaging, Imaging systems, X-ray detectors, Sensing systems

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Proceedings Article | 1 June 2020 Paper

Paper

Task-specific information in x-ray diffraction and transmission modalities: a comparative analysis

Yijun Ding, David Coccarelli, Ava Hurlock, Joel Greenberg, Michael Gehm, Amit Ashok

Proceedings Volume 11404, 114040H (2020) https://doi.org/10.1117/12.2558267

KEYWORDS: Scattering, Sensors, X-ray diffraction, X-rays, Scatter measurement, Photon counting, X-ray detectors, Signal to noise ratio, Signal attenuation, Photodetectors

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Proceedings Article | 29 May 2020 Paper

Paper

Motion analysis of event-based sensors

Joseph Cox, Nicholas Morley, Amit Ashok

Proceedings Volume 11396, 113960D (2020) https://doi.org/10.1117/12.2556652

KEYWORDS: Cameras, Sensors, Target detection, Imaging systems, Calibration, Motion analysis, Digital imaging, Machine vision, 3D modeling, Projection systems

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Proceedings Article | 9 September 2019 Paper

Paper

Passive indirect diffuse imaging

Shu Yang, Kwan Kit Lee, Amit Ashok

Proceedings Volume 11138, 111380U (2019) https://doi.org/10.1117/12.2529956

KEYWORDS: Imaging systems, Inverse problems, Reflectivity, Photons, Image acquisition, Image restoration, Reconstruction algorithms

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Proceedings Article | 6 September 2019 Presentation + Paper

Presentation + Paper

Surpassing Rayleigh limit: Fisher information analysis of partially coherent source(s)

Kwan Kit Lee, Amit Ashok

Proceedings Volume 11136, 111360H (2019) https://doi.org/10.1117/12.2528540

KEYWORDS: Coherence (optics), Photon counting, Optical testing, Image analysis, Geometrical optics

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Proceedings Article | 14 May 2019 Presentation

Presentation

Information-theoretic analysis of fixed Gantry x-ray computed tomography transmission system for threat detection (Conference Presentation)

Jay Voris, Yijun Ding, Ratchaneekorn Thamvichai, Joel Greenberg, David Coccarelli, Michael Gehm, Eric Johnson, Carl Bosch, Amit Ashok

Proceedings Volume 10999, 109990I (2019) https://doi.org/10.1117/12.2519812

KEYWORDS: X-ray computed tomography, Computing systems

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Proceedings Article | 14 May 2019 Paper

Paper

Motivations and methods for the analysis of multi-modality x-ray systems for explosives detection

Joshua Carpenter, Yijun Ding, Ava Hurlock, David Coccarelli, Chris Gregory, Souleymane Diallo, Amit Ashok, Michael Gehm, Joel Greenberg

Proceedings Volume 10999, 1099908 (2019) https://doi.org/10.1117/12.2518781

KEYWORDS: X-rays, Scanners, Signal attenuation, X-ray diffraction, Explosives detection, Imaging systems, Data modeling

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Proceedings Article | 14 May 2019 Paper

Paper

X-ray measurement model and information-theoretic metric incorporating material variability with energy correlations

Yijun Ding, Amit Ashok

Proceedings Volume 10999, 109990J (2019) https://doi.org/10.1117/12.2518552

KEYWORDS: Data modeling, X-ray imaging, X-ray detectors, Performance modeling, Statistical modeling

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Proceedings Article | 14 May 2019 Presentation

Presentation

Multiplexed measurement design for fixed Gantry x-ray computed tomography system (Conference Presentation)

Ahmad Masoudi, Amit Ashok

Proceedings Volume 10999, 109990K (2019) https://doi.org/10.1117/12.2519600

KEYWORDS: Multiplexing, X-ray computed tomography, Computing systems, Inspection, X-ray sources, Sensors, Detector arrays, Time metrology

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Proceedings Article | 14 June 2018 Presentation + Paper

Presentation + Paper

An information theoretic approach to system optimization accounting for material variability

David Coccarelli, Joel Greenberg, Ratchaneekorn Thamvichai, Jay Voris, Ahmad Masoudi, Amit Ashok, Michael Gehm

Proceedings Volume 10632, 106320F (2018) https://doi.org/10.1117/12.2305227

KEYWORDS: X-rays, Spectral resolution, Sensors, Radiography, Signal attenuation, Spatial resolution, Signal to noise ratio, X-ray imaging, Computer architecture, Telecommunications

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Proceedings Article | 14 May 2018 Presentation

Presentation

X-ray measurement model and information-theoretic system metric incorporating material variability (Conference Presentation)

Ahmad Masoudi, Jay Voris, David Coccarelli, Joel Greenberg, Michael Gehm, Amit Ashok

Proceedings Volume 10632, 106320H (2018) https://doi.org/10.1117/12.2307242

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Proceedings Article | 27 April 2018 Paper

Paper

Deep learning based sparse view x-ray CT reconstruction for checked baggage screening

Sagar Mandava, Amit Ashok, Ali Bilgin

Proceedings Volume 10632, 1063204 (2018) https://doi.org/10.1117/12.2309509

KEYWORDS: Image restoration, CT reconstruction, Image segmentation, Dual energy imaging, X-ray computed tomography, Data modeling, X-rays, Data acquisition, Systems modeling, Reconstruction algorithms

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Proceedings Article | 7 June 2017 Presentation

Presentation

Adaptive x-ray threat detection using sequential hypotheses testing with fan-beam experimental data (Conference Presentation)

Ratchaneekorn Thamvichai, Liang-Chih Huang, Amit Ashok, Qian Gong, David Coccarelli, Joel Greenberg, Michael Gehm, Mark Neifeld

Proceedings Volume 10187, 101870A (2017) https://doi.org/10.1117/12.2266756

KEYWORDS: Adaptive optics, X-ray optics, Digital x-ray imaging, X-ray imaging, Current controlled current source, X-rays, Data acquisition, Error analysis, X-ray detectors

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Proceedings Article | 7 June 2017 Presentation

Presentation

Lessons learned in the execution of advanced x-ray material discrimination (Conference Presentation)

Sharene Young

Proceedings Volume 10187, 1018702 (2017) https://doi.org/10.1117/12.2266692

KEYWORDS: X-ray optics, Defense and security, Digital x-ray imaging, X-ray imaging, Current controlled current source, X-rays, Explosives, Detector development, X-ray technology

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Proceedings Article | 1 May 2017 Presentation + Paper

Presentation + Paper

Creating an experimental testbed for information-theoretic analysis of architectures for x-ray anomaly detection

David Coccarelli, Joel Greenberg, Sagar Mandava, Qian Gong, Liang-Chih Huang, Amit Ashok, Michael Gehm

Proceedings Volume 10187, 1018709 (2017) https://doi.org/10.1117/12.2263033

KEYWORDS: Sensors, Detector arrays, Data acquisition, Databases, X-rays, Reconstruction algorithms, Temporal resolution, Analytical research, X-ray detectors, Detection and tracking algorithms, Spectral resolution, Spatial resolution, Systems modeling

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Proceedings Article | 1 May 2017 Presentation + Paper

Presentation + Paper

Image reconstruction for view-limited x-ray CT in baggage scanning

Sagar Mandava, David Coccarelli, Joel Greenberg, Michael Gehm, Amit Ashok, Ali Bilgin

Proceedings Volume 10187, 101870F (2017) https://doi.org/10.1117/12.2265491

KEYWORDS: Compressed sensing, Image segmentation, Dual energy imaging, Sensors, Data acquisition, Image restoration, X-rays, X-ray computed tomography, Reconstruction algorithms, X-ray imaging, Scanners

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SPIE Journal Paper | 11 April 2017 Open Access

Open Access

Special Section Guest Editorial: Optical Computational Imaging

Abhijit Mahalanobis, Amit Ashok, Lei Tian

OE, Vol. 56, Issue 04, 041301, (April 2017) https://doi.org/10.1117/12.10.1117/1.OE.56.4.041301

KEYWORDS: Computational imaging, Imaging systems, Mahalanobis distance, Data processing, Image compression, 3D image processing, Multiplexing, Image processing, Target detection, Computing systems

Proceedings Article | 28 September 2016 Presentation + Paper

Presentation + Paper

Visibility thresholds for visually lossy JPEG2000

Feng Liu, Yuzhang Lin, Eze Ahanonu, Michael Marcellin, Amit Ashok, Elizabeth Krupinski, Ali Bilgin

Proceedings Volume 9971, 99711P (2016) https://doi.org/10.1117/12.2238411

KEYWORDS: Visualization, JPEG2000, Image compression, Visual compression, Visibility, Quantization, Wavelets, Chromium, Distortion, Computer programming

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Proceedings Article | 20 May 2016 Paper

Paper

Scalable information-optimal compressive target recognition

Ronan Kerviche, Amit Ashok

Proceedings Volume 9870, 987008 (2016) https://doi.org/10.1117/12.2228570

KEYWORDS: Target recognition, Compressive imaging, Imaging systems, Signal to noise ratio, Device simulation, Target recognition, Statistical modeling, Principal component analysis, Image compression, Projection systems, Radon

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Proceedings Article | 12 May 2016 Paper

Paper

Information-theoretic analysis of x-ray scatter and phase architectures for anomaly detection

David Coccarelli, Qian Gong, Razvan-Ionut Stoian, Joel Greenberg, Michael Gehm, Yuzhang Lin, Liang-Chih Huang, Amit Ashok

Proceedings Volume 9847, 98470B (2016) https://doi.org/10.1117/12.2223175

KEYWORDS: X-rays, X-ray imaging, Imaging systems, Sensors, Systems modeling, Scattering, Laser scattering, Signal attenuation, Phase measurement, Data modeling

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Proceedings Article | 12 May 2016 Paper

Paper

Information optimal compressive x-ray threat detection

James Huang, Amit Ashok

Proceedings Volume 9847, 98470T (2016) https://doi.org/10.1117/12.2223784

KEYWORDS: X-rays, Multiplexing, Probability theory, X-ray detectors, Tomography, 3D metrology, 3D modeling, Sensors, X-ray imaging, Systems modeling

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Proceedings Article | 12 May 2016 Paper

Paper

Information-theoretic analysis of x-ray photoabsorption based threat detection system for check-point

Yuzhang Lin, Genevieve Allouche, James Huang, Amit Ashok, Qian Gong, David Coccarelli, Razvan-Ionut Stoian, Michael Gehm

Proceedings Volume 9847, 98470F (2016) https://doi.org/10.1117/12.2223803

KEYWORDS: Detector arrays, X-rays, X-ray detectors, Spectral resolution, Sensors, Computing systems, Detection and tracking algorithms, Signal to noise ratio, Dual energy imaging, Statistical analysis

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Proceedings Article | 20 October 2014 Paper

Paper

Information optimal compressive imaging: design and implementation

Amit Ashok, James Huang, Yuzhang Lin, Ronan Kerviche

Proceedings Volume 9186, 91860K (2014) https://doi.org/10.1117/12.2063947

KEYWORDS: Imaging systems, Compressive imaging, Quantization, Image restoration, Image compression, Digital micromirror devices, Image acquisition, Reconstruction algorithms, Calibration, Signal to noise ratio

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Proceedings Article | 8 June 2012 Paper

Paper

Compressive sensing of frequency-hopping spread spectrum signals

Feng Liu, Yookyung Kim, Nathan Goodman, Amit Ashok, Ali Bilgin

Proceedings Volume 8365, 83650P (2012) https://doi.org/10.1117/12.919561

KEYWORDS: Compressed sensing, Signal to noise ratio, Modulation, Interference (communication), Associative arrays, Switching, Chromium, Frequency shift keying, Receivers, Signal processing

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Proceedings Article | 8 September 2011 Paper

Paper

Compressive light field imaging with weighted random projections

Amit Ashok, Mark Neifeld

Proceedings Volume 8165, 816519 (2011) https://doi.org/10.1117/12.894367

KEYWORDS: Wavelets, Imaging systems, Image compression, Spatial frequencies, Spatial resolution, Signal to noise ratio, Detector arrays, Solids, Image resolution, Discrete wavelet transforms

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Proceedings Article | 3 June 2011 Paper

Paper

Space-time feature-specific imaging

Vicha Treeaporn, Amit Ashok, Mark Neifeld

Proceedings Volume 8056, 80560P (2011) https://doi.org/10.1117/12.884440

KEYWORDS: Imaging systems, Image compression, Staring arrays, Compressive imaging, Discrete wavelet transforms, Sensors, Video, Image processing, Photodetectors, Optical components

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Proceedings Article | 28 August 2010 Paper

Paper

Adaptive compressive imaging for object reconstruction

Jun Ke, Amit Ashok, Mark Neifeld

Proceedings Volume 7818, 781809 (2010) https://doi.org/10.1117/12.861738

KEYWORDS: Signal to noise ratio, Imaging systems, Sensors, Compressive imaging, Reconstruction algorithms, Error analysis, Spatial light modulators, Radon, Electronics engineering, Wavelets

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Proceedings Article | 14 May 2010 Paper

Paper

Compressive light field imaging

Amit Ashok, Mark Neifeld

Proceedings Volume 7690, 76900Q (2010) https://doi.org/10.1117/12.852738

KEYWORDS: Imaging systems, Image compression, Sensors, Spatial resolution, Signal to noise ratio, Image sensors, Optical testing, Time metrology, Detector arrays, Image resolution

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Proceedings Article | 25 April 2007 Paper

Paper

Task-specific information: an imaging system analysis tool

Amit Ashok, Pawan Baheti, Mark Neifeld

Proceedings Volume 6575, 65750G (2007) https://doi.org/10.1117/12.720878

KEYWORDS: Imaging systems, Target detection, Signal to noise ratio, Computer programming, Sensors, Image compression, Error analysis, Classification systems, Binary data, Stochastic processes

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Proceedings Article | 18 May 2006 Paper

Paper

Recent progress on multidomain optimization for ultrathin cameras

Amit Ashok, Mark Neifeld

Proceedings Volume 6232, 62320N (2006) https://doi.org/10.1117/12.668280

KEYWORDS: Imaging systems, Point spread functions, Detector arrays, Signal to noise ratio, Image resolution, Sensors, Image quality, Cameras, Optical engineering, Computer programming

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Showing 5 of 39 publications

Proceedings Volume Editor (12)

SPIE Conference Volume | 14 July 2023

Anomaly Detection and Imaging with X-Rays (ADIX) VIII

SPIE Conference Volume | 28 June 2022

Anomaly Detection and Imaging with X-Rays (ADIX) VII

SPIE Conference Volume | 5 May 2021

Anomaly Detection and Imaging with X-Rays (ADIX) VI

SPIE Conference Volume | 2 June 2020

Anomaly Detection and Imaging with X-Rays (ADIX) V

SPIE Conference Volume | 26 July 2019

Anomaly Detection and Imaging with X-Rays (ADIX) IV

Showing 5 of 12 publications

Conference Committee Involvement (19)

Anomaly Detection and Imaging with X-Rays (ADIX) IX

24 April 2024 | National Harbor, Maryland, United States

Anomaly Detection and Imaging with X-Rays (ADIX) VIII

3 May 2023 | Orlando, Florida, United States

Computational Imaging VII

1 May 2023 | Orlando, Florida, United States

Anomaly Detection and Imaging with X-Rays (ADIX) VII

4 April 2022 | Orlando, Florida, United States

Anomaly Detection and Imaging with X-Rays (ADIX) VI

12 April 2021 | Online Only, Florida, United States

Computational Imaging VI

12 April 2021 | Online Only, Florida, United States

Computational Imaging V

27 April 2020 | Online Only, California, United States

Anomaly Detection and Imaging with X-Rays (ADIX) V

27 April 2020 | Online Only, California, United States

Anomaly Detection and Imaging with X-Rays (ADIX) IV

15 April 2019 | Baltimore, MD, United States

Computational Imaging IV

14 April 2019 | Baltimore, MD, United States

Anomaly Detection and Imaging with X-Rays (ADIX) III

17 April 2018 | Orlando, FL, United States

Computational Imaging III

15 April 2018 | Orlando, FL, United States

Anomaly Detection and Imaging with X-Rays (ADIX) II

12 April 2017 | Anaheim, CA, United States

Computational Imaging II

9 April 2017 | Anaheim, CA, United States

Anomaly Detection and Imaging with X-Rays (ADIX)

19 April 2016 | Baltimore, MD, United States

Computational Imaging

17 April 2016 | Baltimore, MD, United States

Visual Information Processing XXI

24 April 2012 | Baltimore, Maryland, United States

Three-Dimensional Imaging, Visualization, and Display 2011

27 April 2011 | Orlando, Florida, United States

Visual Information Processing XX

26 April 2011 | Orlando, Florida, United States

Showing 5 of 19 Conference Committees

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