Prof. Daniel Leo Lau Profile

Prof. Daniel Leo Lau

Assistant Professor at Univ of Kentucky

SPIE Involvement:

Conference Program Committee | Author

Publications (27)

SPIE Journal Paper | 10 November 2023

Real-time compensation of projector lens distortion using a linear-grid model in fringe projection profilometry

Yi Bai, Geyou Zhang, Daniel Lau, Bo Zhang, Bin Xu, Kai Liu

OE, Vol. 62, Issue 11, 114103, (November 2023) https://doi.org/10.1117/12.10.1117/1.OE.62.11.114103

KEYWORDS: Distortion, Projection systems, Fringe analysis, Point clouds, 3D modeling, Optical engineering, Cameras, Optical spheres, Error analysis, Binary data

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Proceedings Article | 6 September 2019 Paper

Per-pixel calibration using CALTag and dense 3D point cloud reconstruction

Karelia Pena-Pena, Xiao Ma, Daniel Lau, Gonzalo Arce

Proceedings Volume 11137, 111371C (2019) https://doi.org/10.1117/12.2529332

KEYWORDS: Calibration, Cameras, Clouds, 3D modeling, Imaging systems, Near infrared, 3D image processing, Sensors

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Proceedings Article | 4 March 2019 Presentation + Paper

3D scanning by means of dual-projector structured light illumination

Ying Yu, Daniel Lau, Matthew Ruffner

Proceedings Volume 10932, 109320M (2019) https://doi.org/10.1117/12.2510990

KEYWORDS: Cameras, Projection systems, Field programmable gate arrays, Structured light, Scanners, Calibration, Video, 3D image processing, 3D scanning

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Proceedings Article | 4 March 2019 Paper

Structured light smart camera for spatial augmented reality applications

Matthew Ruffner, Ying Yu, Daniel Lau

Proceedings Volume 10932, 109320J (2019) https://doi.org/10.1117/12.2508553

KEYWORDS: Cameras, Video, Field programmable gate arrays, Image sensors, Projection systems, Clocks, Structured light, Sensors

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Proceedings Article | 22 February 2018 Paper

Universal phase unwrapping for phase measuring profilometry using geometry analysis

Jianwen Song, Yo-Sung Ho, Daniel Lau, Kai Liu

Proceedings Volume 10546, 105460B (2018) https://doi.org/10.1117/12.2289423

KEYWORDS: 3D modeling, Structured light, Spatial frequencies

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Proceedings Article | 20 February 2017 Paper

Side information in coded aperture compressive spectral imaging

Laura Galvis, Henry Arguello, Daniel Lau, Gonzalo Arce

Proceedings Volume 10117, 101170H (2017) https://doi.org/10.1117/12.2252167

KEYWORDS: Coded apertures, RGB color model, Imaging systems, Digital micromirror devices, Compressed sensing, Image compression, 3D image processing, Sensors, Reconstruction algorithms, Spatial light modulators

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SPIE Journal Paper | 7 May 2014 Open Access

Nonlinearity calibrating algorithm for structured light illumination

Kai Liu, Shuaijun Wang, Daniel Lau, Kenneth Barner, Fouad Kiamilev

OE, Vol. 53, Issue 05, 050501, (May 2014) https://doi.org/10.1117/12.10.1117/1.OE.53.5.050501

KEYWORDS: Laser imaging, Calibration, Projection systems, Distortion, Cameras, Detection and tracking algorithms, Electrical engineering, Nonlinear optics, Illumination engineering, Structured light

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Proceedings Article | 13 February 2012 Paper

Measurement of human subjects using structured light

Matthew Bellis, Daniel Lau

Proceedings Volume 8254, 82540F (2012) https://doi.org/10.1117/12.924838

KEYWORDS: Human subjects, Cameras, 3D metrology, Motion measurement, Calibration, Signal to noise ratio, Scanners, Projection systems, 3D modeling, Structured light

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SPIE Journal Paper | 1 July 2010

Quality and matching performance analysis of three-dimensional unraveled fingerprints

Yongchang Wang, Qi Hao, Abhishika Fatehpuria, Laurence Hassebrook, Daniel Lau

OE, Vol. 49, Issue 07, 077202, (July 2010) https://doi.org/10.1117/12.10.1117/1.3465571

KEYWORDS: Image quality, 3D image processing, 3D scanning, 3D acquisition, Scanners, 3D printing, Optical engineering, Sensors, Projection systems, Algorithm development

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SPIE Journal Paper | 1 September 2008

Improved composite-pattern structured-light profilometry by means of postprocessing

Chun Guan, Laurence Hassebrook, Daniel Lau, V. G. Yalla, Charles Casey

OE, Vol. 47, Issue 09, 097203, (September 2008) https://doi.org/10.1117/12.10.1117/1.2981559

KEYWORDS: Composites, Cameras, Projection systems, Image processing, 3D modeling, 3D image reconstruction, Modulation, Laser imaging, 3D image processing, Demodulation

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SPIE Journal Paper | 1 January 2008

Alpha stable modeling of human visual systems for digital halftoning in rectangular and hexagonal grids

Alvaro Gonzalez, Jan Bacca-Rodriguez, Gonzalo Arce, Daniel Lau

JEI, Vol. 17, Issue 01, 013004, (January 2008) https://doi.org/10.1117/12.10.1117/1.2898122

KEYWORDS: Halftones, Visual process modeling, Systems modeling, Eye models, Visual system, Mathematical modeling, Eye, Point spread functions, Visualization, Image filtering

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Proceedings Article | 3 May 2007 Paper

Multicamera phase measuring profilometry for accurate depth measurement

Yongchang Wang, Kai Liu, Qi Hao, Daniel Lau, Laurence Hassebrook

Proceedings Volume 6555, 655509 (2007) https://doi.org/10.1117/12.720068

KEYWORDS: Cameras, Projection systems, 3D acquisition, 3D modeling, Laser imaging, Imaging systems, Distortion, 3D vision, Phase matching, Structured light

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Proceedings Article | 3 May 2007 Paper

Super resolution structured light illumination

Laurence Hassebrook, Akshay Pethe, Charles Casey, Veera Ganesh Yalla, Daniel Lau

Proceedings Volume 6555, 655508 (2007) https://doi.org/10.1117/12.719703

KEYWORDS: Cameras, Spatial light modulators, Projection systems, Video, Laser imaging, Scanners, Digital Light Processing, Beam splitters, Super resolution, Structured light

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Proceedings Article | 12 April 2007 Paper

Performance analysis of three-dimensional ridge acquisition from live finger and palm surface scans

Abhishika Fatehpuria, Daniel Lau, Veeraganesh Yalla, Laurence Hassebrook

Proceedings Volume 6539, 653904 (2007) https://doi.org/10.1117/12.719891

KEYWORDS: Image quality, 3D scanning, Scanners, 3D acquisition, 3D image processing, Reliability, Biometrics, Sensors, Software development, Feature extraction

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Proceedings Article | 19 May 2006 Paper

Expanding range of pulsed range sensors with active projection from spatial light modulators

Xiaodong Xun, Wei Su, Robert Cohn, Laurence Hassebrook, Daniel Lau

Proceedings Volume 6220, 62200I (2006) https://doi.org/10.1117/12.665843

KEYWORDS: Spatial light modulators, Cameras, Sensors, Diffraction, Complex systems, 3D image processing, Beam steering, Liquid crystals, Imaging systems, Active sensors

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Proceedings Article | 19 May 2006 Paper

Real-time composite pattern demodulation using optical correlators

Daniel Lau, Laurence Hassebrook, Thomas Lu, Tien-Hsin Chao

Proceedings Volume 6220, 62200F (2006) https://doi.org/10.1117/12.665902

KEYWORDS: Composites, Spatial light modulators, Laser imaging, Cameras, Video, Image processing, Modulation, Demodulation, Optical correlators, Structured light

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Proceedings Article | 18 May 2006 Paper

Implementation of 3D linear phase coefficient composite filters

Delicia Woon, Laurence Hassebrook, Daniel Lau, ZhenZhou Wang

Proceedings Volume 6234, 62340I (2006) https://doi.org/10.1117/12.666392

KEYWORDS: Head, Composites, Linear filtering, Image filtering, Target detection, Clouds, Facial recognition systems, Error analysis, 3D acquisition, Distortion invariant pattern recognition

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Proceedings Article | 17 April 2006 Paper

Acquiring a 2D rolled equivalent fingerprint image from a non-contact 3D finger scan

Abhishika Fatehpuria, Daniel Lau, Laurence Hassebrook

Proceedings Volume 6202, 62020C (2006) https://doi.org/10.1117/12.666127

KEYWORDS: 3D scanning, 3D acquisition, 3D image processing, Sensors, Feature extraction, Image quality, Image acquisition, Biometrics, 3D modeling, Clouds

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Proceedings Article | 3 February 2006 Paper

Alpha stable human visual system models for digital halftoning

A. González, J. Bacca, G. Arce, D. Lau

Proceedings Volume 6057, 60570J (2006) https://doi.org/10.1117/12.643540

KEYWORDS: Halftones, Eye models, Eye, Point spread functions, Mathematical modeling, Visual process modeling, Visual system, Gaussian filters, Visualization, Binary data

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Proceedings Article | 17 January 2006 Paper

Real-time multi-spectral color acquisition and display using commodity hardware components

Andrew Tan, Daniel Lau

Proceedings Volume 6062, 60620O (2006) https://doi.org/10.1117/12.643522

KEYWORDS: Cameras, Projection systems, Optical filters, RGB color model, Video, LCDs, Imaging systems, Laser imaging, Image registration, Skin

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Proceedings Article | 16 January 2006 Paper

Optimal halftoning over hexagonal grids

J. Bacca Rodríguez, A. González Lozano, G. Arce, D. Lau

Proceedings Volume 6058, 605811 (2006) https://doi.org/10.1117/12.643527

KEYWORDS: Halftones, Algorithm development, Printing, Diffusion, Visual process modeling, Binary data, Fourier transforms, Visual system, Optimization (mathematics), Visualization

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Halftoning approaches to image rendering on binary devices have traditionally relied on rectangular grids for dot placement. This practice has been followed mainly due to restrictions on printer hardware technology. However, recent advances on printing devices coupled with the availability of efficient interpolation and resampling algorithms are making the implementation of halftone prints over alternate dot placement tessellations feasible. This is of particular interest since blue noise dithering principles indicate that the visual artifacts at several tone densities, which appear in rectangular-grid halftones, can be overcome through the use of hexagonal tessellations. While the spectral analysis of blue noise dithering provides the desired spectral characteristics one must attain, it does not provide the dithering structures needed to achieve these. In this paper, these optimal dithering mechanisms are developed through modifications of the Direct Binary Search (DBS) algorithm extensively used for rectangular grids. Special attention is given to the effects of the new geometry on the Human Visual System (HVS) models and on the efficient implementation of the hexagonal-grid DBS. This algorithm provides the best possible output at the expense of high computational complexity, and while the DBS algorithm is not practical in most applications, it provides a performance benchmark for other more practical algorithms. Finally, a tone-dependent, hexagonal-grid, error-diffusion algorithm is developed, where the DBS algorithm is used to optimize the underlying filter weights. The characteristics of the HVS are thus implicitly used in the optimization. Extensive simulations show that hexagonal grids do indeed reduce disturbing artifacts, providing smoother halftone textures over the entire gray-scale region. Results also show that tone-dependent error-diffusion can provide comparable results to that of the DBS algorithms but at a significantly lower computational complexity.

Proceedings Article | 19 May 2005 Paper

Active pattern projection for increasing range of pulsed range sensors

Wei Su, Laurence Hassebrook, Daniel Lau

Proceedings Volume 5798, (2005) https://doi.org/10.1117/12.603886

KEYWORDS: Spatial light modulators, Cameras, Sensors, Infrared radiation, Camera shutters, Video, Signal to noise ratio, Light, Pulsed laser operation, Surveillance

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Proceedings Article | 19 May 2005 Paper

Composite pattern structured light projection for human computer interaction in space

Chun Guan, Laurence Hassebrook, Daniel Lau, Veera Ganesh Yalla

Proceedings Volume 5798, (2005) https://doi.org/10.1117/12.603808

KEYWORDS: Composites, Cameras, Projection systems, Computer programming, 3D modeling, Reconstruction algorithms, Picosecond phenomena, 3D image processing, 3D image reconstruction, Structured light

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Proceedings Article | 2 November 2004 Paper

Multispectral color acquisition and display using commodity hardware

Daniel Lau, Ruigang Yang, Andrew Tan, Wei Su, Laurence Hassebrook

Proceedings Volume 5558, (2004) https://doi.org/10.1117/12.556525

KEYWORDS: Cameras, Projection systems, Video, Optical filters, RGB color model, Imaging systems, Displays, Image filtering, CCD cameras, Image registration

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Proceedings Article | 22 October 2004 Paper

Optical processing of composite pattern structured light projection for high-speed depth measurement

Chun Guan, Laurence Hassebrook, Daniel Lau

Proceedings Volume 5557, (2004) https://doi.org/10.1117/12.560260

KEYWORDS: Composites, Cameras, Image processing, Computer programming, Eye, Modulation, Image filtering, 3D image processing, Optical signal processing, Structured light

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Proceedings Article | 14 August 2003 Paper

Real-time 3D data acquisition for augmented-reality man and machine interfacing

Chun Guan, Laurence Hassebrook, Daniel Lau

Proceedings Volume 5097, (2003) https://doi.org/10.1117/12.487276

KEYWORDS: 3D acquisition, Composites, Cameras, Human-computer interaction, Modulation, Video, Acquisition tracking and pointing, Human-machine interfaces, Projection systems, Structured light

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Proceedings Article | 2 June 2000 Paper

Evaluation of green noise masks for electrophotographic halftoning

Brian Cooper, Daniel Lau

Proceedings Volume 3959, (2000) https://doi.org/10.1117/12.387194

KEYWORDS: Printing, Halftones, Diffusion, Distortion, Binary data, Visualization, Moire patterns, Nonimpact printing, Visibility, Stochastic processes

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