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Search Publications by: David W. Allen (Fed)

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Displaying 1 - 25 of 83

Certification of Standard Reference Material(R) 2196 Axial Resolution Standard for Optical Medical Imaging

February 7, 2023
Author(s)
Jeeseong C. Hwang, Kimberly Briggman, Nikki Rentz, Hyun-Jin Kim, David W. Allen, Lee J. Richter, Sowon Yoon, John Lu
Medical imaging devices and systems must be calibrated to ensure uniformity and reliability of test results. A standard reference material (SRM) or "phantom", as it is known in the medical imaging community, is used to replicate fundamental characteristics

Polydimethylsiloxane tissue-mimicking phantoms with tunable optical properties

July 1, 2022
Author(s)
Aaron Goldfain, Paul Lemaillet, David W. Allen, Kimberly Briggman, Jeeseong C. Hwang
We report on techniques to manufacture and characterize solid tissue-mimicking phantoms of polydimethylsiloxane (PDMS) polymers. Tunability of the absorption (a()) and reduced scattering spectra (s'()) in the wavelength range of 500 nm to 850 nm is

Quantification of urban biogenic carbon fluxes using bottom-up inventory and satellite-based model

January 5, 2022
Author(s)
Joy Winbourne, Hrstiana Stoynova, Ian Smith, Conor Gately, Barry Logan, Jaret Reblin, Andrew Reinmann, David W. Allen, Lucy Hutyra
Cities across the globe are taking the lead on climate mitigation action with ambitious goals to reduce carbon dioxide (CO2) emissions. The implementation of effective mitigation policies will require accurate measurements to guide policy decisions and

Reference data set and variability study for human skin reflectance

June 30, 2019
Author(s)
P. Yvonne Barnes, David W. Allen, Benjamin K. Tsai
The optical properties of human skin have been of interest to researchers for some time. Their interest is based on a need to know for a variety of different applications, which range from spectral imaging for automated or stand-off detection, non-invasive

Exposure Study on the Aging of PTFE and Ceramic Diffusers

February 6, 2019
Author(s)
Benjamin K. Tsai, Catherine C. Cooksey, David W. Allen, Christopher C. White, Walter E. Byrd, Deborah S. Jacobs
This paper describes efforts to quantify the effects of aging in the ultraviolet (UV) on polytetrafluoroethylene (PTFE) and ceramic samples. Long term UV aging may significantly alter the reflectance factor and cause an error in the calibration of

Correction of an adding-doubling inversion algorithm for the measurement of the optical parameters of turbid media

January 1, 2018
Author(s)
Paul Lemaillet, Catherine C. Cooksey, Jeeseong Hwang, Heidrun Wabnitz, Dirk Grosenick, Lin Yang, David W. Allen
We present broadband measurements of the optical properties of tissue-mimicking solid phantoms using a single integrating sphere to measure the hemispherical reflectance and transmittance under a direct illumination at the normal incident angle. These

Approaches for Characterizing Nonlinear Mixtures in Hyperspectral Imagery

June 21, 2017
Author(s)
Robert S. Rand, Ronald G. Resmini, David W. Allen
This study considers a physics-based and a kernel-based approach for characterizing pixels in a scene that may be linear (areal mixed) or nonlinear (intimately mixed). The physics-based method is based on earlier studies that indicate nonlinear mixtures in

Reference Data Set of Human Skin Reflectance

June 7, 2017
Author(s)
Catherine C. Cooksey, David W. Allen, Benjamin K. Tsai
This data set contains 100 reference reflectance spectra of human skin, spanning the wavelength region from 250 nm to 2500 nm. The spectra were acquired with a commercial spectrophotometer and are directly traceable to the national scale for directional

Broadband spectral measurements of diffuse optical properties by an integrating sphere instrument at the National Institute of Standards and Technology

March 30, 2017
Author(s)
Paul Lemaillet, Jeeseong Hwang, Heidrun Wabnitz, Dirk Grosenick, Lin Yang, David W. Allen
Diffuse materials that approximate the optical properties of human tissue are commonly used as phantoms. In order to use the phantoms in a manner that provides consistent results relative to independent measurements, the optical properties need to be tied

Label-free hyperspectral dark-field microscopy towards quantitative scatter imaging

March 27, 2017
Author(s)
Philip Cheney, David McClatchy III, Stephen Kanick, Paul Lemaillet, David W. Allen, Daniel Samarov, Brian Pogue, Jeeseong C. Hwang
A hyperspectral dark-field microscopy technique has been developed for imaging spatially distributed diffuse reflectance spectra from light-scattering samples. In this report, quantitative scatter spectroscopy was demonstrated with a uniform scattering

Towards Establishing Compact Imaging Spectrometer Standards

March 31, 2016
Author(s)
David W. Allen, Elmer T. Slonecker, Ronald G. Resmini
Remote sensing science is currently undergoing a tremendous expansion in the area of hyperspectral imaging (HSI) technology. Spurred largely by the explosive growth of Unmanned Aerial Vehicles (UAV), sometimes called Unmanned Aircraft Systems (UAS), or

National Institute of Standards and Technology measurement service of the optical properties of biomedical phantoms: Current status

March 24, 2016
Author(s)
Paul Lemaillet, Catherine C. Cooksey, Zachary H. Levine, Adam L. Pintar, Jeeseong Hwang, David W. Allen
The National Institute for Standards and Technology (NIST) has maintained scales of reflectance and transmittance over several decades. Those scales are primarily intended for the regular transmittance, mirrors, and solid surface scattering diffusers. The

An Overview of Spectral Imaging of Human Skin toward Face Recognition

February 13, 2016
Author(s)
David W. Allen
Spectral imaging is a form of remote sensing that provides a means of collecting information from surroundings without physical contact. Differences in spectral reflectance over the electromagnetic spectrum allow for the detection, classification, or

Double-integrating-sphere system at the National Institute of Standards and Technology in support of measurement standards for the determination of optical properties of tissue-mimicking phantoms

October 27, 2015
Author(s)
Paul Lemaillet, Jeeseong C. Hwang, David W. Allen
There is a need for a common reference point that will allow for the comparison of the optical properties of tissue mimicking phantoms. This paper provides a brief review of the methods that have been used to measure tissue mimicking phantoms. The review

Digital Phantoms Generated by Spectral and Spatial Light Modulators

October 21, 2015
Author(s)
Bonghwan Chon, Fuyuki Tokumasu, Ji Y. Lee, David W. Allen, Joseph P. Rice, Jeeseong Hwang
A hyperspectral image projector (HIP) based on liquid crystal on silicon (LCoS) spatial light modulators (SLMs) is explained and demonstrated to generate 3D spectral data cubes. The HIP- constructed data cubes are 3D images of the spatial distribution of

Development of traceable measurement of the diffuse optical properties of solid reference standards for biomedical optics at the National Institute of Standards and Technology

July 1, 2015
Author(s)
David W. Allen, Paul Lemaillet, Jean-Pierre Bouchard
The development of a national reference instrument dedicated to the measurement of the scattering and absorption properties of solid tissue-mimicking phantoms used as reference standards is presented. The optical properties of the phantoms are measured

Spectral reflectance variability of skin and attributing factors

May 21, 2015
Author(s)
Catherine C. Cooksey, Benjamin K. Tsai, David W. Allen
Knowledge of the spectral reflectance signature of human skin over a wide spectral range will help advance the development of sensing systems for many applications, ranging from medical treatment to security technology. A critical component of the

Bidirectional reflectance scale comparison between NIST and PTB

May 1, 2015
Author(s)
Catherine C. Cooksey, Maria E. Nadal, David W. Allen, Kai-Olaf Hauer, Andreas Hoepe
A comparison of bidirectional reflectance scales between the National Institute of Standards and Technology (NIST) and the Physikalisch-Technische Bundesanstalt (PTB) has been performed. Measurements of two sets of white diffuse reflectance standards, two

Making digital phantoms with spectral and spatial light modulators for quantitative applications of hyperspectral optical medical imaging devices

March 6, 2015
Author(s)
Bonghwan Chon, fuyuki Tokumasu, Ji Youn Lee, David W. Allen, Joseph P. Rice, Jeeseong C. Hwang
We present a procedure to generate digital phantoms with a hyperspectral image projector (HIP) consisting of two liquid crystal on silicon (LCoS) spatial light modulators (SLMs). The digital phantoms are 3D image data cubes of the spatial distribution of