A new image processing method for evaluating the pupillary responses in a HMD-type eye-tracking device

Lin, Chern‐Sheng; Lue, Li Wen; Yeh, Mau Shiun; Hwang, Thong Shing; Lee, Su Hsin

doi:10.1016/s0030-3992(03)00063-x

Cited by 7 publications

(2 citation statements)

References 15 publications

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“…To determine a subject's selective adaptation to spatial frequencies and contrast, the subject looks at a grating of the same brightness for about 30 s. Then the screen is refreshed, and the subject looks briefly at the next test grating (Lin, Lue, Yeh, Hwang, & Lee, 2003). The video signals from the HMD and CCTV display device are tested and evaluated using a digital signal processing (DSP) unit.…”

Section: Prototype Technical Testingmentioning

confidence: 99%

Evaluating the Image Quality of Closed Circuit Television Magnification Systems Versus a Head-Mounted Display for People With Low Vision

Lin

Jan

Lay

et al. 2014

Assistive Technology

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In this research, image analysis was used to optimize the visual output of a traditional Closed Circuit Television (CCTV) magnifying system and a head-mounted display (HMD) for people with low vision. There were two purposes: (1) To determine the benefit of using an image analysis system to customize image quality for a person with low vision, and (2) to have people with low vision evaluate a traditional CCTV magnifier and an HMD, each customized to the user's needs and preferences. A CCTV system can electronically alter images by increasing the contrast, brightness, and magnification for the visually disabled when they are reading texts and pictures. The test methods was developed to evaluate and customize a magnification system for persons with low vision. The head-mounted display with CCTV was used to obtain better depth of field and a higher modulation transfer function from the video camera. By sensing the parameters of the environment (e.g., ambient light level, etc.) and collecting the user's specific characteristics, the system could make adjustments according to the user's needs, thus allowing the visually disabled to read more efficiently.

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Section: Prototype Technical Testingmentioning

confidence: 99%

Evaluating the Image Quality of Closed Circuit Television Magnification Systems Versus a Head-Mounted Display for People With Low Vision

Lin

Jan

Lay

et al. 2014

Assistive Technology

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“…It allowed for pupil measurements at a sampling frequency of up to 120 Hz and with a spatial resolution of 0.03 mm. In [ 13 , 14 ], the authors proposed a video-based eye tracker. It used video cameras to record the eye position of human subjects and record pupil size and eye movements.…”

Section: Introductionmentioning

confidence: 99%

System and measurement method for binocular pupillometry to study pupil size variability

et al. 2014

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BackgroundAn objective and noninvasive examination of pupil size variability can be used to assess the activity of the autonomous nervous system. We designed a system that enables binocular, fast, and accurate recordings of different types of pupil variabilities, which are synchronous with other biosignals. This type of measurement system is needed to extend the scope of pupillometry applications.MethodsIn the proposed system, the left and right eyes are independently and interchangeably illuminated to generate alternating images, which are successively acquired by a single camera. The system is composed of four functional modules: the image acquisition module, the image processing unit, the light stimulator, and the controller. The proposed image processing algorithm approximates the shape of the pupil using the best-fit ellipse. The user control panel (controller) precisely sets the stimuli parameters and controls the entire measurement procedure.ResultsThe computer-based binocular system records the pupil size during the pupil light reflexes (direct and indirect) and spontaneous pupil size fluctuations, at a sampling rate up to 75 Hz, with a resolution better than 0.02 mm. Our initial laboratory tests confirmed that the new system is fast and precise (system accuracy better than 0.5% and repeatability better than 4%).ConclusionsThe proposed system’s unique geometry and construction, and the method it uses to detect images from each eye, allows us to monitor the right and left eyes using a single camera with no overlap between the images. The system does not require a very experienced operator, because it is relatively simple and easy to use. Importantly, it is comfortable for the subjects. Additionally, the presented system can operate with other bio-measurement systems using a synchronous signal. These system capabilities can expand the scope of pupillometry research applications.

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A Pupil Location Method for WIFI-based Video-oculography System

Chen

2012

AASRI Procedia

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A new image processing method for evaluating the pupillary responses in a HMD-type eye-tracking device

Cited by 7 publications

References 15 publications

Evaluating the Image Quality of Closed Circuit Television Magnification Systems Versus a Head-Mounted Display for People With Low Vision

Evaluating the Image Quality of Closed Circuit Television Magnification Systems Versus a Head-Mounted Display for People With Low Vision

System and measurement method for binocular pupillometry to study pupil size variability

A Pupil Location Method for WIFI-based Video-oculography System

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