• Title/Summary/Keyword: Pupil

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Realistic Expression Factors According to Visual Presence in Terms of Iris color and Pupil Accommodation of Virtual Avatar (가상 아바타의 홍채색과 동공 조절에 따른 시각적 실재감에 대한 실감표현요소)

  • Won, Myoung Ju;Park, Sang-In;Lee, Eui Chul;Whang, Min-Cheol
    • The Journal of the Korea Contents Association
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    • v.14 no.4
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    • pp.1-8
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    • 2014
  • The virtual avatar is a principal way as media for communicating language and affective feelings in virtual environment. As similar purpose, this study evaluates user's visual feeling according to the changes of iris color and pupil size of virtual avatar which is considered as new factors for representing realistic avatar. Virtual avatars were configured by pupil accommodation and iris color(green, brown). After presenting above image to 32 participants, a questionnaire(18 items) based on previous studies was created, and reported as a 5-point scale. Experimental result showed that the case of adopting pupil accommodation induced more realistic visual feeling of subjects. This result can be regarded as a basis for designing realistic virtual avatar by confirming the effectiveness of pupil accommodation of avatar in terms of representing visual presence.

Development of Real-Time Vision-based Eye-tracker System for Head Mounted Display (영상정보를 이용한 HMD용 실시간 아이트랙커 시스템)

  • Roh, Eun-Jung;Hong, Jin-Sung;Bang, Hyo-Choong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.6
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    • pp.539-547
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    • 2007
  • In this paper, development and tests of a real-time eye-tracker system are discussed. The tracker system tracks a user's gaze point through movement of eyes by means of vision-based pupil detection. The vision-based method has an advantage of detecting the exact positions of user's eyes. An infrared camera and a LED are used to acquire a user's pupil image and to extract pupil region, which was hard to extract with software only, from the obtained image, respectively. We develop a pupil-tracking algorithm with Kalman filter and grab the pupil images by using DSP(Digital Signal Processing) system for real-time image processing technique. The real-time eye-tracker system tracks the movements of user's pupils to project their gaze point onto a background image.

Webcam-Based 2D Eye Gaze Estimation System By Means of Binary Deformable Eyeball Templates

  • Kim, Jin-Woo
    • Journal of information and communication convergence engineering
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    • v.8 no.5
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    • pp.575-580
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    • 2010
  • Eye gaze as a form of input was primarily developed for users who are unable to use usual interaction devices such as keyboard and the mouse; however, with the increasing accuracy in eye gaze detection with decreasing cost of development, it tends to be a practical interaction method for able-bodied users in soon future as well. This paper explores a low-cost, robust, rotation and illumination independent eye gaze system for gaze enhanced user interfaces. We introduce two brand-new algorithms for fast and sub-pixel precise pupil center detection and 2D Eye Gaze estimation by means of deformable template matching methodology. In this paper, we propose a new algorithm based on the deformable angular integral search algorithm based on minimum intensity value to localize eyeball (iris outer boundary) in gray scale eye region images. Basically, it finds the center of the pupil in order to use it in our second proposed algorithm which is about 2D eye gaze tracking. First, we detect the eye regions by means of Intel OpenCV AdaBoost Haar cascade classifiers and assign the approximate size of eyeball depending on the eye region size. Secondly, using DAISMI (Deformable Angular Integral Search by Minimum Intensity) algorithm, pupil center is detected. Then, by using the percentage of black pixels over eyeball circle area, we convert the image into binary (Black and white color) for being used in the next part: DTBGE (Deformable Template based 2D Gaze Estimation) algorithm. Finally, using DTBGE algorithm, initial pupil center coordinates are assigned and DTBGE creates new pupil center coordinates and estimates the final gaze directions and eyeball size. We have performed extensive experiments and achieved very encouraging results. Finally, we discuss the effectiveness of the proposed method through several experimental results.

A study on characteristics of the autonomic nervous system in students with Keongke - Using Heart Rate Variability and Pupil Size Variability - (경계(驚悸) 증상을 지닌 학생 집단의 자율 신경 기능 특성에 대한 연구 - 심박변이도와 동공크기 변이도를 중심으로 -)

  • Lee, Seung-Gi;Lee, Jeong-Chan;Kim, Ji-Eun;Park, Kyung-Mo;Kang, Hee-Chul
    • Journal of Oriental Neuropsychiatry
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    • v.17 no.2
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    • pp.133-145
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    • 2006
  • Objective : The purpose of this experimental-controlled study was to investigate the characteristics of the autonomic nervous system in students with Keongke by using HRV(Heart rate variability) and PSV(Pupil size variability). Method : The study group was consisted of 11 students with self recognition as the experimental group, and 25 normal students as the control group. Informations on gender and age were obtained by medical charts and personal interviews. By using heart rate variability and pupil size variability, we measured the value of HRT(Heart rate), SDNN(Standard deviation of NN intervals), LFnorm(Low frequency normalization), HFnorm(High frequency normalization), LF/HF ratio, Pupil area, B.S.(Basic size), C.R.(Max Constriction Rate) and 1s.d.(1sec Dilation Rate). I compared the degrees of the sympathetic and parasympathetic activity. Result : 1. In the result of heart rate variability between experimental and control group, none of the parameters of experimental group were significantly different from control group. And even though there were no statistical significance, there were some numerical differences in SDNN, LF norm, HF norm. 2. In pupil size variability, C.R. and 1s.d. of the experimental group were increased compared to control group. Conclusion : The study results suggest that the group with Keongke has differences of autonomic nervous system as compared to those in normal state. Measurement value of PSV is a new technical approach to estimate the autonomic nervous system.

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Implementation of 2-D Incoherent Imaging using Hilbert Transform based on Two-Pupil Optical Heterodyne Scanning System (Two-Pupil 광학 헤테로다인 스캐닝 시스템 기반의 힐버트 변환을 활용한 2-D 인코히어런트 이미징 구현)

  • Kyung, Min-Gu;Doh, Kyu-Bong
    • Journal of Advanced Navigation Technology
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    • v.16 no.2
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    • pp.240-246
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    • 2012
  • The Hilbert transform, which has been hitherto discussed in coherent imaging, is for the first time investigated in the context of incoherent imaging. Because the Hilbert transform of the information is superposed coherently with the original light field. We present a two-pupil optical heterodyne scanning system and analyze mathematically the design of its two pupils such that the optical system can perform the Hilbert transform on incoherent objects. In this paper, we review and formulate the definition of an analytic signal of a function and from which we can obtain the Hilbert transform of the function. and we analyze the design of pupils so as to obtain the Hilbert transform and show some 2-D simulations. Computer simulation results of the idea clarify the theoretical results.

A Scheme for User Authentication using Pupil (눈동자를 이용한 사용자 인증기법)

  • Lee, Jae-Wook;Kang, Bo-Seon;Lee, Keun-Ho
    • Journal of Digital Convergence
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    • v.14 no.9
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    • pp.325-329
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    • 2016
  • Facial authentication has the limelight because it has less resistance and it is hard to falsify among various biometric identification. The algorithm of facial authentication can bring about huge difference in accuracy and speed by the algorithm construction. Along with face-extracted data by tracing and extracting pupil, the thesis studied algorithm which extracts data to improve error rate and to accurately authenticate face. It detects face by cascade, selects as significant area, divides the facial area into 4 equal parts to save the coordinate of object. Also, to detect pupil from the eye, the binarization is conducted and it detects pupil by Hough conversion. The core coordinate of detected pupil is saved and calculated to conduct facial authentication through data matching. The thesis studied optimized facial authentication algorithm which accurately calculates facial data with pupil trace.

The Difference in Pupil Size Responding to Cognitive Load and Emotional Arousal Questions between Guilty and Innocent Groups (유죄 및 무죄 집단 간 인지적 부하 및 정서적 각성 질문에 따른 동공크기의 변화의 차이)

  • Cho, Ara;Kim, Kiho;Lee, Jang-Han
    • Korean Journal of Forensic Psychology
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    • v.11 no.2
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    • pp.155-171
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    • 2020
  • The purpose of this study is to examine the effects of emotional arousal and cognitive load on pupil diameter during a lie detection interview. The guilty group (n = 30) committed a mock crime (i.e., stealing cash) and the innocent group (n = 30) performed a mission (i.e., sending a message) in the research assistant's office. After that, their pupil size was measured using a wearable eye-tracker during the interview. The interview questions were classified with the three cognitive load, three emotional arousal, and three neutral questions. The results indicate that the main effects of group and time were not significant, but the interaction between group and time was significant. It means that when answering cognitive load questions, the guilty group showed larger increase in pupil diameter than the innocent group. The present study suggests that inducing cognitive load is more effective than inducing emotional arousal during an interview when using pupil diameter as an index of deception, and it is expected to improve the accuracy of lie detection.

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A Fast Iris Region Finding Algorithm for Iris Recognition (홍채 인식을 위한 고속 홍채 영역 추출 방법)

  • 송선아;김백섭;송성호
    • Journal of KIISE:Software and Applications
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    • v.30 no.9
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    • pp.876-884
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    • 2003
  • It is essential to identify both the pupil and iris boundaries for iris recognition. The circular edge detector proposed by Daugman is the most common and powerful method for the iris region extraction. The method is accurate but requires lots of computational time since it is based on the exhaustive search. Some heuristic methods have been proposed to reduce the computational time, but they are not as accurate as that of Daugman. In this paper, we propose a pupil and iris boundary finding algorithm which is faster than and as accurate as that of Daugman. The proposed algorithm searches the boundaries using the Daugman's circular edge detector, but reduces the search region using the problem domain knowledge. In order to find the pupil boundary, the search region is restricted in the maximum and minimum bounding circles in which the pupil resides. The bounding circles are obtained from the binarized pupil image. Two iris boundary points are obtained from the horizontal line passing through the center of the pupil region obtained above. These initial boundary points, together with the pupil point comprise two bounding circles. The iris boundary is searched in this bounding circles. Experiments show that the proposed algorithm is faster than that of Daugman and more accurate than the conventional heuristic methods.

Comparison of the Refracting Power and Aberration according to the Measurement Change in Illumination and Area of the Pupils (조도와 동공 영역의 측정 변화에 따른 굴절력과 수차의 비교)

  • Kim, Bong-Hwan;Han, Seon-Hee;Park, Byeong-Gyu;Hwang, Hyeon-Ju;Bae, Ye-Sol;Seo, Jeong-Bin;Yeo, Ye-Eun;Yoon, Min-Jeong;Kim, Hak-Jun
    • Journal of Korean Clinical Health Science
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    • v.4 no.2
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    • pp.550-555
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    • 2016
  • Purpose. We compared with the refracting power and aberration according to the measurement change in illumination and the pupils area by using the auto refraction instruments. Methods. In this study it were examined 64 eyes without eye disease, 21.4 (${\pm}2.54$) age, 32 (male 10, female 22) patients. Experiments in general illumination using the auto refraction instruments (HRK-8000A, Huvitz, Korea) was measured in both eyes 3 times and after scotopic for 30 minutes in a dark room blocked the light was measured in the same way. Aberration were measured coma, spherical aberration, high and low order aberrations in a general illumination (3500 lux) and low illumination (5 lux) of the pupil area 3.96 mm and 5.96 mm. Results. In the general illumination for measuring of the pupil area, the refractive power, coma, spherical aberration and low order aberration was no significant difference. In the low illumination, spherical aberration of the pupil area was $0.005({\pm}0.015){\mu}m$ in a 3.96mm, $0.014({\pm}0.020){\mu}m$ in a 5.96 mm and appeared a significant difference(p = 0.003). In general and low illumination on the results of comparing the measured values of the refractive power and aberration at the pupil area 3.96 mm, high order aberrations was $0.205({\pm}0.145){\mu}m$ in general illumination, $0.132({\pm}0.075){\mu}m$ in low illumination and appeared a significant differences(p = 0.001). High order aberrations at the pupil area 5.96 mm was $0.278({\pm}0.244){\mu}m$ in general illumination, $0.150({\pm}0.092){\mu}m$ in low illumination and appeared a significant differences(p = 0.000). Conclusions. When the eye refractive power measured by the automatic refraction does not depend on the illumination conditions and size of the observation pupil area, it was found that aberrations are affected by the illumination and the observation pupil area. It was found that the eye examination chamber illumination to obtain accurate measurement produces better results to decrease than to increase.

Changes in the Covering of Pupil and the Visual Acuity by the Illuminance when Wearing Circle Soft Contact Lens (써클 소프트콘택트렌즈 착용 시 조도에 따른 동공의 가려짐과 시력 변화)

  • Kim, So Ra;Choi, Jae Hyung;Lee, Kang-Geun;Park, Mijung
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.1
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    • pp.19-25
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    • 2013
  • Purpose: The degree of the pupil covered with tinted region of circle soft contact lens was determined according to the illuminant conditions in everyday life and the change of visual acuity by its covering was further investigated. Methods: The circle contact lens having the non-tinted area of 6.2 mm in the center of the lens was applied on 82 eyes in their 20s and their minimum separable visual acuity and minimum legible visual acuity were determined under the luminances of 50 and 370 lux. Results: The covering of pupil was not found when wearing circle contact lens under 370 lux, however, some pupil covering ranged from 0.40 to 1.70 mm was observed in all subjects under 50 lux. The minimum separable visual acuity and minimum legible visual acuity were significantly decreased by the wearing of circle contact lens under 50 lux and the correlation between the larger pupil size of subjects and more decrease of visual acuity was observed. Furthermore, the decrease of minimum separable visual acuity was larger than the case of minimum legible visual acuity indicating that minimum separable visual acuity was largely affected by the covering of pupil. Conclusions: The consideration is necessary for the lens wearers and the manufacturers since the wearing circle contact lens in low-light indoor or nighttime activities may affect directly visual acuity.