Marshall University students participate in breakthrough developments at AFB TECH Optic Lab

MEDIA ADVISORY FROM MARSHALL UNIVERSITY COMMUNICATIONS
ONE JOHN MARSHALL DRIVE, HUNTINGTON, WV 25755

FOR IMMEDIATE RELEASE
Monday, June 23, 2008
Contact: Lee Huffman, AFB TECH, (304) 523-8651, and/or Lalena Price, Marshall University Communications, (304) 746-1989

Marshall University students participate
in breakthrough developments at AFB TECH Optic Lab

Technology demonstration to take place on Wednesday

HUNTINGTON, W.Va. – Imagine not being able to read the small screens found on everything from cell phones to iPods or microwaves to life-saving diabetes equipment. Unfortunately, that is the reality for 20 million Americans who say they have trouble seeing even with the aid of glasses or contact lenses.

On Wednesday, June 25, the American Foundation for the Blind Technology and Employment Center (AFB TECH), with the help of Marshall University students and professors, will unveil a new device designed to measure contrast of digital displays.

The device, developed by Marshall University physicist Dr. Thomas Wilson and engineered by faculty and students of the Marshall University College of Information Technology and Engineering in conjunction with AFB TECH, is the first step in determining the level of contrast necessary to make digital displays usable by people with vision loss. At the event, AFB TECH and Marshall University staff will demonstrate how this technology works.

“With the U.S. population aging and the vision loss numbers expected to increase substantially, more and more people will need technology to be accessible,” said Mark Uslan, director of AFB TECH. “We hope this project will ultimately lead to manufacturing standards that ensure small screen displays are readable for everyone.”

Marshall University professor Joe Fuller said the goal of the AFB project is to ensure that people with vision loss can fully participate in our increasingly digital world. He said it was an exciting project for the computer science students that participated.

“I am very grateful to Mark Uslan and AFB for giving our students the opportunity to work in a real-world environment,” Fuller said. “It was also gratifying to see how well they performed.”

WHAT:	Technology demonstration
WHEN:	10 a.m. Wednesday, June 25
WHERE:	AFB TECH Optics Lab 949 3rd Ave., Suite 200, Huntington, W.Va.
WHO:	Lee Huffman, National Technology Associate, AFB TECH Jack Smith, Ph.D., CEGAS (Center for Environmental, Geotechnical and Applied Science) Thomas Wilson, Ph.D., Marshall University physicist and project developer Joe Fuller, Marshall University Computer Science professor Russell Farmer, junior, Weisberg Division of Engineering & Computer Science Department at Marshall University Jacob Bills, sophomore, Weisberg Division of Engineering & Computer Science Department at Marshall University Steven Taylor, Marshall University Yeager Scholar

AAPM-TG18: Assessment of Display Performance for Medical Imaging Systems

The American Association of Physicists in Medicine (AAPM) Task Group 18 is a national task force consisting of medical imaging experts and organizational affiliates dealing with performance evaluation of electronic display devices. The purpose of the Task Group is to generate a document that provides guidelines to practicing medical physicists and engineers for in-field performance evaluation of electronic display devices intended for medical use.

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Download the full AAPM-TG18 report (PDF), or the Executive summary (PDF).

Sample results

Here are some sample results from the re-engineered system.

The following is a histogram plot in IMAQ Vision Builder showing high and low luminance profiles used in a Michelson Contrast measure.



The following is an edge profile and an SFR (MTF) plot from Imatest.



The following is an SQF chart from Imatest.

Re-engineered system

The re-engineered contrast measurement system for passive LCD displays is now operational. The optics equipment comprises a Canon EOS 40D DSLR camera, a Canon EF 100mm f/2.8 Macro USM lens, a set of Kenko extension tubes, a Newport iris diaphragm, and a SphereOptics integrating sphere housing a fan-cooled 4-watt 12v lamp powered by an Agilent E3634A power supply. The mechanical hardware includes a vibration-free optics table, rails, posts, post holders, and various positional stages to hold and align the optics equipment and the target LCD device. The software comprises DSLR Remote Pro from Breeze Systems, IMAQ Vision Builder from National Instruments, and Imatest Studio running on a laptop computer connected to the camera via USB and the power supply via USB/RS-232.

Vision Assistant

From National Instruments...

Vision Assistant is an interactive prototyping and 'what-if' environment for prototyping vision applications. Vision Assistant allows you to learn easily image processing and investigate vision software strategies without programming. Unlike any other interactive vision development tool, Vision Assistant generates a text description - a recipe of the machine vision and image processing functions that provides a guide for developing applications with IMAQ Vision in LabVIEW, BridgeVIEW, LabWindows/CVI, and Component Works with Microsoft Visual Basic and Visual C.

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Vision Assistant (IMAQ Vision Builder) has been selected to perform certain image analyses (e.g., line profiles for luminance) for the LCD MTF measurement system.

SQRI Image Quality Metric as a Measure to Predict Character Recognition for Small Visual Displays

By Ronald A. Schuchard, Ph.D., Director, Rehabilitation R&D Center of Excellence, Associate Professor, Emory University School of Medicine

The prevalence of small, often low contrast, visual displays in our society is increasing at a large rate. Some examples of devices that employ small visual displays include cellular phones, personal digital assistants (PDA), home blood pressure monitors (HBPM) and glucometers. These devices, many of which employ low-cost reflective liquid crystal displays, can obviously pose a strong text-recognition challenge for the person with vision loss. The greatest cause of vision loss in the US is macular diseases (including age-related macular degeneration and diabetic retinopathy). In particular, people with macular diseases commonly have central scotomas and/or reduced contrast sensitivity. People with central scotomas (80% of all people with low vision) have functional problems because of the “hole” in the middle of their visual field (caused by central scotomas, also named; central visual field loss; CFL) which leads to problems of reduced visual function associated with the eccentric preferred retinal locus (PRL). As the fine resolution of the human eye is designed to be used on the central visual axis at the fovea, reduced visual acuity and contrast sensitivity is associated with the use of these eccentric PRLs. However, even the fovea can have impaired visual acuity and contrast sensitivity when macular diseases such as diabetic retinopathy impact the fovea.

The goal of this research effort is to investigate the relationship between successful recognition of a single digit / character presented by a small visual display as a function of the contrast ability of a person with vision loss (specifically contrast sensitivity vision loss) using a small visual display and a corresponding image quality metric. The latter will be computed from measurable optical properties of a home blood pressure monitor display, and the contrast sensitivity function of the person with vision loss.

Standard clinical tests will be performed of near visual acuity, letter contrast sensitivity, central visual field loss including mapping the boundaries of central scotomas, and reading performance. Standard research testing will be performed for determining the contrast sensitivity function (threshold contrast ability to detect gratings of different frequencies), dominant eye for perception, and threshold contrast ability to correctly identify characters / digits on a visual display.

The comparison of the contrast characteristics of the visual display with the contrast detection ability of the person is computed to determine a special metric called the Barten SQRI. This Barten SQRI will be compared to the person’s threshold contrast ability to correctly identify the digits on the visual display to determine whether the Barten SQRI can be used to predict the ability of people with low vision to accurately use small visual displays. If this metric accurately predicts performance then vision rehabilitation specialists and visual display manufacturers can use this metric to help people with central visual function loss.

Sekonic PRODIGI COLOR C-500

The new Sekonic PRODIGI COLOR C-500 and C-500R is the world's only photographic color meter designed to read spectral sensitivity of both color film and CCD and CMOS sensors used in modern digital still and DV cine cameras.

Serious photographers and cinematographers know that good lighting and proper exposure are more important now than ever. With the higher demands of today's digital medium, 'garbage in' can mean hours of postproduction. They know that color is a critical factor when multiple light sources are involved. Changing reflectors, adding diffusion or adjusting power levels will result in a color temperature change that needs to be corrected. They know that taking the time to do it right is always a good investment because 'perfect in' always looks better than an image that has been adjusted.

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This is the color meter chosen for the LCD MTF measurement system to set the color temperature (white balance) on the EOS 40D camera. Here is the product brochure (PDF).