• International Journal of Contents
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• v.2 no.3
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• pp.27-32
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• 2006

We present an effective algorithm for automatic tracing of retinal vessel structure and vascular landmark extraction of bifurcations and ending points. In this paper we deal with vascular patterns from RGB images for personal identification. Vessel tracing algorithms are of interest in a variety of biometric and medical application such as personal identification, biometrics, and ophthalmic disorders like vessel change detection. However eye surface vasculature tracing in RGB images has many problems which are subject to improper illumination, glare, fade-out, shadow and artifacts arising from reflection, refraction, and dispersion. The proposed algorithm on vascular tracing employs multi-stage processing of ten-layers as followings: Image Acquisition, Image Enhancement by gray scale retinal image enhancement, reducing background artifact and illuminations and removing interlacing minute characteristics of vessels, Vascular Structure Extraction by connecting broken vessels, extracting vascular structure using eight directional information, and extracting retinal vascular structure, and Vascular Landmark Extraction by extracting bifurcations and ending points. The results of automatic retinal vessel extraction using jive different thresholds applied 34 eye images are presented. The results of vasculature tracing algorithm shows that the suggested algorithm can obtain not only robust and accurate vessel tracing but also vascular landmarks according to thresholds.

• Journal of the Korea Society of Computer and Information
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• v.13 no.4
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• pp.97-103
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• 2008

This study is to present a fainting motion recognizing method by using fish-eye lens images to sense emergency situations. The camera with fish-eye lens located at the center of the ceiling of the living room sends images, and then the foreground pixels are extracted by means of the adaptive background modeling method based on the Gaussian complex model, which is followed by tracing of outer points in the foreground pixel area and the elliptical mapping. During the elliptical tracing, the fish-eye lens images are converted to fluoroscope images. the size and location changes, and moving speed information are extracted to judge whether the movement, pause, and motion are similar to fainting motion. The results show that compared to using fish-eye lens image, extraction of the size and location changes. and moving speed by means of the conversed fluoroscope images has good recognition rates.

• Journal of the Optical Society of Korea
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• v.14 no.1
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• pp.55-62
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• 2010

We introduce a new method for lens design that combines an eyepiece with the finite model eye, to make a corrected version of the accommodation-dependent Navarro eye. The optical system that we designed, which includes a human eye, takes into account the aberration of the eye and increases the performance of the image in the retina. In the design results, for the optimized eyepiece combined with the corrected Navarro eye, visual acuity is 1.40. Compared with the existing method of eyepiece design using inverse ray tracing with the corrected Navarro eye, MTF value was recorded as 0.079 to 0.283 at 160 lp/mm and visual performance was improved.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.379-382
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• 2005

This study proposes an effective algorithm that can render a realistic image of a lighting environment, especially an automotive rear lamp, using the backward ray tracing method. To producea realistic image similar to that perceived by the human eye, the incident light energy at the eye point estimated by a ray tracing algorithm is represented by XYZ tri-stimulus values, which are then converted into RGB values considering the particular display device.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.203-207
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• 2002

In this study, by using the eye model of NAVARRO, KOOIJMAN, MAHKICHOONG, the properties of optical system are reserched in a finite ray tracing method, when ametropia is corrected by glasses or contact lens, this study is useful as a reference. Also, when Auto-refractometer for refraction test and Keratomeler are designed, these eye models can be used.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.3
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• pp.301-309
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• 2015

Purpose: This study was aimed to design new schematic eyes for presbyopia using the Navarro eye model and clinical data. Methods: We collected clinical data of eye-optical parameters of males in their age of 40, 50, and 60 from previous studies, and designed schematic eyes for presbyopia using the ZEMAX program. Results: The presbyopic process and features of the designed schematic eyes well accorded with the clinical data of previous studies. Conclusions: On the basis of the Navarro eye model, a finite schematic eyes for presbyopia were newly designed corresponding with clinical data.

• Korean Journal of Optics and Photonics
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• v.26 no.6
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• pp.299-305
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• 2015

Using Snell's Law without approximation, we analyzed focal points for parallel rays incident upon the cornea of a human eye. To calculate a ray's incident angle versus incident height for focusing on the same point, we used the ray reverse tracing method. We derived the theoretical conditions for an aspherical lens to remove the spherical aberration caused by a human eye. In this research, we held the rear surface of the lens to be spherical, for simple calculation, and calculated the lens curvature of the front surface to design an aspherical surface.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.5
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• pp.123-131
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• 1997

To ensure drive's field of view, obstruction area generated by a steering wheel, hub and spoke must be considered at the early stage of automobile design. The current approach to computing obstruction area proposed by SAE is based on 2D drafting procedures so that it is not precise and errorprone. In the paper we discuss the novel approach which models the obstruction area as the shadows of the steering wheel, hub and spoke by assuming the human eye as light sources. The approach is based on ray tracing and space transformations for that it can be applied when free form curves are hired to represent the steering wheel, hub and spoke in CAD environment. As a result, it gives more predise and reliable results than SAE approach.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.6
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• pp.175-182
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• 2020

The non-contact eye tracking is a nonintrusive human-computer interface providing hands-free communications for people with severe disabilities. Recently. it is expected to do an important role in non-contact systems due to the recent coronavirus COVID-19, etc. This paper proposes a novel approach for an eye mouse using an eye tracking method based on a context-aware based AdaBoost multi-region classifier and ASSL algorithm. The conventional AdaBoost algorithm, however, cannot provide sufficiently reliable performance in face tracking for eye cursor pointing estimation, because it cannot take advantage of the spatial context relations among facial features. Therefore, we propose the eye-region context based AdaBoost multiple classifier for the efficient non-contact gaze tracking and mouse implementation. The proposed method detects, tracks, and aggregates various eye features to evaluate the gaze and adjusts active and semi-supervised learning based on the on-screen cursor. The proposed system has been successfully employed in eye location, and it can also be used to detect and track eye features. This system controls the computer cursor along the user's gaze and it was postprocessing by applying Gaussian modeling to prevent shaking during the real-time tracking using Kalman filter. In this system, target objects were randomly generated and the eye tracking performance was analyzed according to the Fits law in real time. It is expected that the utilization of non-contact interfaces.

• Smart Media Journal
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• v.5 no.3
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• pp.62-66
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• 2016

The recent increase in virtual reality (VR) technology around the world has been VR work in cooperation with technology from other sectors to form new trends. In the case of advertising, it is difficult to trace if VR users viewed a certain piece of advertisement because the current technology does not allow them to interact with the screen. Eye tracking technology can act as a solution to the problem of tracing advertisement views as it allows for data extraction in relation to which advertisements were viewed and for how long. The research paper suggests a method of how to track the eyes of users in VR advertising. The suggested method includes communication between a server and VR HMD (virtual reality head mounted display) as well as a screen of output from the server.