Dr. Joseph van der Gracht Profile

Dr. Joseph van der Gracht

Research Scientist at HoloSpex Inc

SPIE Involvement:

Author

Publications (20)

Proceedings Article | 30 April 2009 Paper

A practical enhanced-resolution integrated optical-digital imaging camera (PERIODIC)

M. Mirotznik, S. Mathews, R. Plemmons, P. Pauca, T. Torgersen, R. Barnard, B. Gray, Q. Zhang, J. van der Gracht, P. Curt, M. Bodnar, S. Prasad

Proceedings Volume 7348, 734806 (2009) https://doi.org/10.1117/12.819484

KEYWORDS: Imaging systems, Cameras, Super resolution, Imaging arrays, High dynamic range imaging, Optical components, Image processing, Image resolution, CCD cameras, Charge-coupled devices

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Proceedings Article | 3 September 2008 Paper

Pupil phase encoding for multi-aperture imaging

V. Pauca, D. Chen, J. van der Gracht, R. Plemmons, S. Prasad, T. Torgersen

Proceedings Volume 7074, 70740D (2008) https://doi.org/10.1117/12.795985

KEYWORDS: Imaging systems, Point spread functions, Super resolution, Sensors, Image resolution, Cameras, Computer programming, Digital imaging, Inverse optics, Spatial resolution

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Proceedings Article | 25 April 2008 Paper

Extended depth of field imaging at 94 GHz

Joseph Mait, David Wikner, Mark Mirotznik, Joseph van der Gracht, Gregory Behrmann, Brandon Good, Scott Mathews

Proceedings Volume 6948, 69480C (2008) https://doi.org/10.1117/12.775180

KEYWORDS: Imaging systems, Point spread functions, Image processing, Signal processing, Modulation transfer functions, Optical transfer functions, Focus stacking, Computational imaging, Computing systems, Optical components

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Proceedings Article | 25 August 2006 Paper

High-resolution iris image reconstruction from low-resolution imagery

R. Barnard, V. Pauca, T. Torgersen, R. Plemmons, S. Prasad, J. van der Gracht, J. Nagy, J. Chung, G. Behrmann, S. Mathews, M. Mirotznik

Proceedings Volume 6313, 63130D (2006) https://doi.org/10.1117/12.681930

KEYWORDS: Cameras, Iris recognition, Image resolution, Sensors, Image registration, Image quality, Imaging systems, Prototyping, Charge-coupled devices, Point spread functions

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Proceedings Article | 28 March 2005 Paper

Extended depth-of-field iris recognition system for a workstation environment

Ramkumar Narayanswamy, Paulo Silveira, Harsha Setty, V. Pauca, Joseph van der Gracht

Proceedings Volume 5779, (2005) https://doi.org/10.1117/12.603612

KEYWORDS: Imaging systems, Iris recognition, Wavefronts, Spatial frequencies, Modulation transfer functions, Signal to noise ratio, Sensors, Modulation, Biometrics, Image processing

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Proceedings Article | 26 October 2004 Paper

Pupil-phase optimization for extended-focus, aberration-corrected imaging systems

Sudhakar Prasad, V. Paul Pauca, Robert Plemmons, Todd Torgersen, Joseph van der Gracht

Proceedings Volume 5559, (2004) https://doi.org/10.1117/12.560235

KEYWORDS: Monochromatic aberrations, Point spread functions, Imaging systems, Image restoration, Personal protective equipment, Iris recognition, Modulation transfer functions, Image filtering, Signal to noise ratio, Image quality

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Proceedings Article | 26 October 2004 Paper

Computational imaging systems for iris recognition

Robert Plemmons, Michael Horvath, Emily Leonhardt, V. Pauca, Sudhakar Prasad, Stephen Robinson, Harsha Setty, Todd Torgersen, Joseph van der Gracht, Edward Dowski, Ramkumar Narayanswamy, Paulo Silveira

Proceedings Volume 5559, (2004) https://doi.org/10.1117/12.560186

KEYWORDS: Iris recognition, Imaging systems, Computing systems, Detection and tracking algorithms, Computational imaging, Image restoration, Image processing, Computer programming, Feature extraction, Cameras

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Proceedings Article | 15 July 2004 Paper

Iris recognition with enhanced depth-of-field image acquistion

Joseph van der Gracht, V. Pauca, Harsha Setty, Ramkumar Narayanswamy, Robert Plemmons, Sudhakar Prasad, Todd Torgersen

Proceedings Volume 5438, (2004) https://doi.org/10.1117/12.542151

KEYWORDS: Iris recognition, Detection and tracking algorithms, Imaging systems, Signal to noise ratio, Image restoration, Cameras, Aspheric lenses, Modulation transfer functions, Wavelets, Image filtering

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Proceedings Article | 24 December 2003 Paper

Integrated optical-digital approaches for enhancing image restoration and focus invariance

Victor Pauca, Robert Plemmons, Sudhakar Prasad, Todd Torgersen, Joseph van der Gracht

Proceedings Volume 5205, (2003) https://doi.org/10.1117/12.505309

KEYWORDS: Image restoration, Point spread functions, Modulation transfer functions, Imaging systems, Optical transfer functions, Interference (communication), Optical design, Integrated optics, Fourier transforms, Wavefronts

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Proceedings Article | 6 October 2003 Open Access

Visual experimentation

Ravindra Athale, Joseph van der Gracht

Proceedings Volume 9663, 96630B (2003) https://doi.org/10.1117/12.2208376

KEYWORDS: Visualization, Computer generated holography, Visual optics, Photonics, Electrochemical etching, Diffraction gratings, Spectroscopy, Light sources, Reflectivity, Optical filters

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Proceedings Article | 8 August 2003 Paper

Engineering the pupil phase to improve image quality

Sudhakar Prasad, Todd Torgersen, Victor Pauca, Robert Plemmons, Joseph van der Gracht

Proceedings Volume 5108, (2003) https://doi.org/10.1117/12.487572

KEYWORDS: Image restoration, Point spread functions, Image quality, Modulation transfer functions, Personal protective equipment, Imaging systems, Computer simulations, Signal to noise ratio, Computer programming, Monochromatic aberrations

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Proceedings Article | 30 July 2002 Paper

Experimental investigation of aliasing in the assessment of sampled images

Joseph van der Gracht, Gary Euliss, Victor Pauca

Proceedings Volume 4736, (2002) https://doi.org/10.1117/12.477570

KEYWORDS: Image filtering, Imaging systems, Cameras, Signal to noise ratio, Sensors, Optical filters, Spatial frequencies, Electronic filtering, Error analysis, Image registration

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Proceedings Article | 30 July 2002 Paper

Design of a diffractive anti-aliasing filter using information density

Joseph Mait, Joseph van der Gracht, Gary Euliss

Proceedings Volume 4736, (2002) https://doi.org/10.1117/12.477571

KEYWORDS: Signal to noise ratio, Optical transfer functions, Visual information processing, Imaging systems, Spatial frequencies, Sensors, Signal attenuation, Optical design, Optical filters, Phase only filters

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Proceedings Article | 28 August 2001 Paper

Information-optimized extended depth-of-field imaging systems

Joseph van der Gracht, Gary Euliss

Proceedings Volume 4388, (2001) https://doi.org/10.1117/12.438247

KEYWORDS: Imaging systems, Sensors, Signal to noise ratio, Wavefronts, Modulation transfer functions, Spatial frequencies, Image restoration, Image quality, Image quality standards, Information theory

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Proceedings Article | 29 June 2000 Paper

Information theoretic analysis of birefringent antialiasing blur filters in the presence of aberrations

Gary Euliss, Joseph van der Gracht

Proceedings Volume 4041, (2000) https://doi.org/10.1117/12.390472

KEYWORDS: Sensors, Optical filters, Imaging systems, Point spread functions, Image filtering, Information theory, Monochromatic aberrations, Spatial frequencies, Detector arrays, Modulation transfer functions

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Proceedings Article | 11 August 1995 Paper

Aspheric optical elements for extended depth-of-field imaging

Joseph van der Gracht, Edward Dowski, W. Thomas Cathey, John Bowen

Proceedings Volume 2537, (1995) https://doi.org/10.1117/12.216392

KEYWORDS: Imaging systems, Optical transfer functions, Digital filtering, Spatial frequencies, Modulation transfer functions, Diffraction, Sensors, Optical components, Digital imaging, Point spread functions

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Proceedings Article | 1 March 1994 Paper

Role of coherence in optical pattern recognition

Joseph van der Gracht, Joseph Mait, Dennis Prather, Ravindra Athale

Proceedings Volume 2237, (1994) https://doi.org/10.1117/12.169418

KEYWORDS: Point spread functions, Spatial light modulators, Optical correlators, Optical pattern recognition, Signal to noise ratio, Optical signal processing, Phase only filters, Phase shift keying, Image processing, Modulation

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Proceedings Article | 25 October 1993 Paper

Diffractive filter design for SLMs in pattern recognition systems

Joseph Mait, Joseph van der Gracht, Scott Sarama

Proceedings Volume 1959, (1993) https://doi.org/10.1117/12.160294

KEYWORDS: Spatial light modulators, Diffractive optical elements, Pattern recognition, Optical pattern recognition, Fourier transforms, Modulation, Optical filters, Electronic filtering, Image filtering, Quantization

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Proceedings Article | 2 March 1993 Paper

Diffractive filter design for SLMs in optical processing and pattern recognition systems

Joseph Mait, Joseph van der Gracht, Scott Sarama

Proceedings Volume 1732, (1993) https://doi.org/10.1117/12.140403

KEYWORDS: Spatial light modulators, Diffractive optical elements, Optical filters, Pattern recognition, Optical signal processing, Optical pattern recognition, Optical design, Modulation, Holography, Fourier transforms

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Proceedings Article | 16 November 1992 Paper

Photonics for aerospace sensors

John Pellegrino, Eric Adler, Andree Filipov, Lorna Harrison, Joseph van der Gracht, Dale Smith, Tristan Tayag, Edward Viveiros

Proceedings Volume 10269, 102690C (1992) https://doi.org/10.1117/12.161576

KEYWORDS: Photonics, Aerospace engineering, Sensors, Signal processing, Fiber optic communications, Data communications, Optical signal processing, Optical components, Fiber optics, Optical communications

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