• Title/Summary/Keyword: Pupil

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A Study for Non-paraxial Diffraction Caused by Curved Principal Planes (주요면의 만곡에 따른 비근축 회절에 대한 연구)

  • Lee, Jong Ung
    • Korean Journal of Optics and Photonics
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    • v.23 no.1
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    • pp.1-5
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    • 2012
  • According to the paraxial diffraction theory, diffractions of optical systems which have the same wavelength and numerical aperture are always the same, independent of lateral magnification. But the diffractions for optical systems with different magnifications are varied due to the non-paraxial diffraction effect on the imaging of high NA optics. In this study, the non-paraxial diffraction effect is interpreted as a phenomena caused by curved principal planes. Pupil functions and modulation transfer functions of aplanatic conic mirrors are examined as a function of lateral magnification.

An Eye Location based Head Posture Recognition Method and Its Application in Mouse Operation

  • Chen, Zhe;Yang, Bingbing;Yin, Fuliang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.3
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    • pp.1087-1104
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    • 2015
  • An eye location based head posture recognition method is proposed in this paper. First, face is detected using skin color method, and eyebrow and eye areas are located based on gray gradient in face. Next, pupil circles are determined using edge detection circle method. Finally, head postures are recognized based on eye location information. The proposed method has high recognition precision and is robust for facial expressions and different head postures, and can be used in mouse operation. The experimental results reveal the validity of proposed method.

Bright Pupil Effect Compensation in Infra-red Image (적외선 영상에서의 밝은 눈동자 효과 보정)

  • Choi, In-Ho;Kim, Dai-Jin
    • Proceedings of the Korean Information Science Society Conference
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    • 2011.06a
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    • pp.480-483
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    • 2011
  • 눈동자 부분을 밝게 만드는 밝은 눈동자 효과(Bright Pupil Effect)는 적외선 영상에서 사람의 얼굴을 부자연스럽게 보이도록 한다. 본 논문에서는 적외선 영상에서의 눈 검출 및 눈동자 추출과 밝은 눈동자 효과를 제거하는 방법에 대해 제안하였다. 먼저 얼굴 검출을 수행한 뒤, 눈 영역을 검출하고 눈동자 부분을 추출한다. 추출한 눈동자 부분이 적외선 반사에 의해 생성된 것인지를 판단하여 눈동자 주변 영역과의 밝기 차이를 빼줌으로써 적외선 반사에 의해 부자연스러워진 눈동자 부분을 보정한다. 제안한 방법은 디지털 카메라, 캠코더 및 스마트 폰에서 부자연스러운 인물 영상 보정에 적용할 수 있다.

Diffraction Amplitude Distribution of Finite Gaussian Pupil with Residual Aberrations (잔류수차가 있는 유한 가우스 동의 회절진폭 분포)

  • 송영란;이민희;이상수
    • Korean Journal of Optics and Photonics
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    • v.9 no.3
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    • pp.142-145
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    • 1998
  • It is shown that the optical system with Gaussian pupil e, diffraction amplitude distribution is not affected by the presence of residual aberrations. The case of spherical aberration is treated, as an example, and the complex diffraction amplitude distribution at the neighbourhood of the image point is described analytically by using a recurrence formula.

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Point Spread Function of Optical Systems Apodized by Semicircular Array of 2D Aperture Functions with Asymmetric Apodization

  • Reddy, Andra Naresh Kumar;Sagar, Dasari Karuna
    • Journal of information and communication convergence engineering
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    • v.12 no.2
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    • pp.83-88
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    • 2014
  • The simultaneous suppression of sidelobes and the sharpening of the central peak in the process of diffraction pattern detection based on asymmetric apodization have been investigated. Asymmetric apodization is applied to a semicircular array of two-dimensional (2D) aperture functions, which is a series of 'coded-phase arrays of semicircular rings randomly distributed over the central circular region of a pupil function' and is similar to that used in the field of diffractive optics. The point spread function (PSF) of an imaging system with asymmetric apodization of the discrete type has been found to possess a good side with suppressed sidelobes, whereas its bad side contains enhanced sidelobes. Further, the diffracted field characteristics are obtained in the presence of these aperture functions. Asymmetric apodization is helpful in improving the performance of the optical gratings or 2D arrays used in real-time imaging techniques.

A Method to Identify the Identification Eye Status for Drowsiness Monitoring System (졸음 방지 시스템을 위한 눈 개폐 상태 판단 방법)

  • Lee, Juhyeon;Yoo, Hyoungsuk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.12
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    • pp.1667-1670
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    • 2014
  • This paper describes a method for detecting the pupil region and identification of the eye status for driver drowsiness detection system. This program detects a driver's face and eyes using viola-jones face detection algorithm and extracts the pupil area by utilizing mean values of each row and column on the eye area. The proposed method uses binary images and the number of black pixels to identify the eye status. Experimental results showed that the accuracy of classification eye status(open/close) was above 90%.

Pupil Distance Measurement for 3D Display Disparity Control (3D 디스플레이 디스페리티 제어를 위한 안간 거리 측정 방법)

  • Park, Ji-hoon;Lee, Jaesung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.05a
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    • pp.125-128
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    • 2013
  • The reason why visual fatigue occurs while watching 3D TV is because the left/right images of the fixed disparity are played. This paper proposes a measuring method of pupil distance and the 3D location of a viewer using stereo camera modules, and a reflection method of the data into 3D TV.

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Non-Paraxial Diffraction Effect of High NA Objectives (높은 개구수를 가지는 대물렌즈의 비근축 회절효과)

  • Lee, Jong Ung
    • Korean Journal of Optics and Photonics
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    • v.25 no.1
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    • pp.8-13
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    • 2014
  • By using finite ray-tracing and curve fitting, a numerical method to determine the non-paraxial pupil function of a high-NA objective is presented. MTF degradations caused by the non-paraxial diffraction effect are analyzed for on-axial imaging of a far-infrared objective and aberration-free ellipsoidal mirror system. The ellipsoidal mirror system has the same paraxial specifications as the far-infrared objective.

Real-time pupil center detection for gaze tracking (시선추적을 위한 실시간 동공 중심 검출)

  • Lee, Gyung-Ju;Kim, Gye-Young
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2014.01a
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    • pp.59-61
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    • 2014
  • 본 논문에서는 단일의 카메라로부터 획득한 영상에 있는 동공 중심을 실시간으로 검출하는 알고리즘을 제안한다. 제안하는 방법은 원에서 현의 수직이등분선은 그 원의 중심을 지난다는 사실을 이용하여 동공의 현을 찾고 동공 중심을 계산하는 것이다. 먼저 VPF(Variance Projection Function)을 이용해 일차적으로 동공 중심을 탐지한다. 탐지된 중심점을 기준으로 원을 탐색하여 정확한 동공 중심점을 찾는다. 실험을 통하여 제안한 방법은 높은 검출율과 처리시간 관점에서 우수함을 보인다.

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