• Title/Summary/Keyword: Pupil function

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Two-pupil synthesis of optical transfer function in the modified triangular interferometer (변형 삼각간섭계에 있어서 광전달함수의 two-pupil 합성)

  • 김수길
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.2
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    • pp.29-35
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    • 2004
  • We synthesizd and analyzed the optical transfer function(OTF) of the modified triangular interferometer(MTI) using two-pupil synthesis method. In the case of MTI, we demonstrated that we can obtain bipolar functions and complex hologram without bias by two-pupil synthesis method.

Pupil Detection using Hybrid Projection Function and Rank Order Filter (Hybrid Projection 함수와 Rank Order 필터를 이용한 눈동자 검출)

  • Jang, Kyung-Shik
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.8
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    • pp.27-34
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    • 2014
  • In this paper, we propose a pupil detection method using hybrid projection function and rank order filter. To reduce error to detect eyebrows as pupil, eyebrows are detected using hybrid projection function in face region and eye region is set to not include the eyebrows. In the eye region, potential pupil candidates are detected using rank order filter and then the positions of pupil candidates are corrected. The pupil candidates are grouped into pairs based on geometric constraints. A similarity measure is obtained for two eye of each pair using template matching, we select a pair with the smallest similarity measure as final two pupils. The experiments have been performed for 700 images of the BioID face database. The pupil detection rate is 92.4% and the proposed method improves about 21.5% over the existing method..

Detection of Pupil Center using Projection Function and Hough Transform (프로젝션 함수와 허프 변환을 이용한 눈동자 중심점 찾기)

  • Choi, Yeon-Seok;Mun, Won-Ho;Kim, Cheol-Ki;Cha, Eui-Young
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.10a
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    • pp.167-170
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    • 2010
  • In this paper, we proposed a novel algorithm to detect the center of pupil in frontal view face. This algorithm, at first, extract an eye region from the face image using integral projection function and variance projection function. In an eye region, detect the center of pupil positions using circular hough transform with sobel edge mask. The experimental results show good performance in detecting pupil center from FERET face image.

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Analysis of Optical Transfer Function and Phase Error of the Modified Triangular Interferometer

  • Kim, Soo-Gil;Ryeom, Jeong-Duk
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.1
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    • pp.10-18
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    • 2007
  • We synthesize and analyze the optical transfer function(OTF) of the modified triangular interferometer(MTI) using two-pupil synthesis method and we present the optimal MTI, which can obtain any bipolar function by combining a wave plate and a linear polarizer. Also, we analyze its potential phase error sources caused by polarization components.

Robust Pupil Detection using Rank Order Filter and Pixel Difference (Rank Order Filter와 화소값 차이를 이용한 강인한 눈동자 검출)

  • Jang, Kyung-Shik
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.7
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    • pp.1383-1390
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    • 2012
  • In this paper, we propose a robust pupil detection method using rank order filter and pixel value difference in facial image. We have detected the potential pupil candidates using rank order filter. Many false pupil candidates found at eyebrow are removed using the fact that the pixel difference is much at the boundary between pupil and sclera. The rest pupil candidates are grouped into pairs. Each pair is verified according to geometric constraints such as the angle and the distance between two candidates. A fitness function is obtained for each pair using the pixel values of two pupil regions, we select a pair with the smallest fitness value as a final pupil. The experiments have been performed for 400 images of the BioID face database. The results show that it achieves more than 90% accuracy, and especially the proposed method improves the detection rate and high accuracy for face with spectacle.

Pupil Detection using PCA and Hough Transform

  • Jang, Kyung-Shik
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.2
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    • pp.21-27
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    • 2017
  • In this paper, we propose a pupil detection method using PCA(principal component analysis) and Hough transform. To reduce error to detect eyebrows as pupil, eyebrows are detected using projection function in eye region and eye region is set to not include the eyebrows. In the eye region, pupil candidates are detected using rank order filter. False candidates are removed by using symmetry. The pupil candidates are grouped into pairs based on geometric constraints. A similarity measure is obtained for two eye of each pair using PCA and hough transform, we select a pair with the smallest similarity measure as final two pupils. The experiments have been performed for 1000 images of the BioID face database. The results show that it achieves the higher detection rate than existing method.

Development of Videooculograph for Vestibular Function Test (전정 기능 평가를 위한 영상 안구 운동 측정 시스템의 개발)

  • 김수찬;남기창;이원선;김덕원
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.40 no.3
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    • pp.189-198
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    • 2003
  • Videooculography (VOG) is one of the eye-movement measurement methods used for objective evaluation of vestibule -ocular reflex. A key feature of VOG is to estimate accurately the center of pupil and ocular torsion with being less influenced by the upper eyelid droop, eyelashes, corneal reflection, and eye blinks. Especially, it Is important to find the accurate center of the pupil in 3-D VOG because the inaccurate pupil center causes significant errors on measuring torsional eye movement. A new algorithm was proposed to find the center of pupil which is a little influenced by factors mentioned above. In this study, real time three-dimensional VOG which can measure horizontal, vortical, torsional eye movements, and the diameter of pupil was implemented using the proposed method.

Synthesis and Analysis of Optical Transfer Function of the Modified Triangular Interferometer by Two - pupil Synthesis Method

  • Kim, Soo-Gil
    • Journal of the Optical Society of Korea
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    • v.8 no.4
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    • pp.182-187
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    • 2004
  • We synthesized and analyzed the optical transfer function(OTF) of the modified triangular interferometer (MTI) using two-pupil synthesis method. Also, we presented the optimal MTI, which can obtain any bipolar function by combining two wave plates and a linear polarizer. By using the proposed MTI, we can obtain the complex hologram without bias and conjugate image.

A Model of Pupil's Change with Luminance (Luminance에 의한 Pupil의 변화에 대한 모델)

  • Kim, Yong-Geun
    • Journal of Korean Ophthalmic Optics Society
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    • v.1 no.2
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    • pp.7-11
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    • 1996
  • The size of pupil with pupillary light reflex is determined by the amount of a luminance. and it is dependent with the distribution function of the retinal illuminance which is the amount of transmittance for the external light due to the size of pupil, and the detector of cone and rod due to the amount of the luminance. The change of the pupil size with the luminance can be expressed with the mathematical model $$y(x)={\alpha}+{\beta}\frac{1}{1+{e}{x}{p}(x-x_0)/{\theta}}$$ where ${\alpha}$ is the size of the pupil diameter in a maximum value of the luminance, ${\beta}$ is the deviation of the pupil's diameter between maximum and minimum, ${\theta}$ is the parameter showed the degree of a sensitivity. Comparing with the experimental value of P.Moon et al, We known that the equation of the model is very compatible.

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Derivation and error analysis of the optical transfer function using two-pupil synthesis in the modified triangular interferometer (변형 삼각 간섭계의 two-pupil 합성을 이용한 광전달 함수의 유도와 오차원인 분석)

  • Kim, Soo-Gil
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.11a
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    • pp.179-181
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    • 2004
  • 본 논문에서는 변형 삼각간섭계를 이용한 간섭패턴 생성과 관련한 몇 가지 실험결과를 제시한다. Two-pupil 합성 방법을 이용하여 변형 삼각간섭계의 광전달함수를 합성하고 광전달함수에 내포된 오차에 대한 원인을 분석해 보았다.

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