• Korean Journal of Optics and Photonics
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• v.26 no.2
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• pp.88-97
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• 2015

An omnidirectional optical system can be described as a special optical system that images in real time a panoramic image with an azimuthal angle of $360^{\circ}$ and the altitude angle corresponding to the upper and lower fields of view from the horizon line. In this paper, for easy fabrication and compact size, we designed and fabricated a catadioptric omnidirectional optical system consisting of the mirror part of a spherical mirror with a central hole (that is, obscuration), a plane mirror, the imaging lens part of 3 single spherical lenses, and a spherical doublet in the visible light spectrum. We evaluated its image performance by measuring the cut-off spatial frequency using automobile license plates, and the vertical field of view using an ISO 12233 chart. We achieved a catadioptric omnidirectional optical system with vertical field of view from $+53^{\circ}$ to $-17^{\circ}$ and an azimuthal angle of $360^{\circ}$. This optical system cleaniy imaged letters on a car's front license plate at the object distance of 3 meters, which corresponds to a cut-off spatial frequency of 135 lp/mm.

• Proceedings of the KAIS Fall Conference
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• 2008.11a
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• pp.254-256
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• 2008

어안 영상은 화각이 일반 카메라 영상보다 큰 반면, 영상의 피사체 왜곡이 커서 사용자의 인지에 자연스럽지 못하다. 그래서 어안 영상은 원근 영상으로 변환하여 사용하는 것이 일반적이다. 본 논문에서는 스케일링 함수를 이용한 어안 영상의 원근 영상 변환 방법을 제안하였다. 특히 스케일링 함수를 적용한 결과 영상에서 크기 왜곡과 기하학적 왜곡을 감소되는 장점을 보였다.

• Proceedings of the KAIS Fall Conference
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• 2008.05a
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• pp.273-274
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• 2008

어안 렌즈 카메라로 촬영한 어안 영상은 화각이 일반 카메라 영상보다 크다. 반면 영상의 피사체 왜곡이 커서 사용자의 인지에 자연스럽지 못하므로 원근 영상으로 변환하여 사용하는 것이 일반적이다. 본 논문에서는 선형 스케일링을 이용한 어안 영상의 원근 영상 변환 방법을 제안하였다. 선형 스케일링을 적용한 결과 영상에서 크기 왜곡과 기하학적 왜곡을 감소되는 장점을 보였다.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.5
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• pp.421-426
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• 2009

The emissivity is different because the emitted angle changes according to the position of the infrared thermography camera and object. Because of this, the temperature distribution expressed when measuring the temperature by using the infrared thermography system is not the accuracy temperature. Although the real surface temperature is constant, the temperature measured by using infrared thermography camera have error in accordance with the value of emissivity. In this paper, the temperatures of the round cylindrical object and the flat square object that heated to the equal temperature were measured by infrared thermography camera. The emissivity calibration formula and correction table are made with the affect of the view angle and emission angle form the surface temperature value. The error of measured temperature values are corrected by using the emissivity calibration formula and correction table, and apply to defect detection of the nuclear power plant pipe. From the calibration method, reliability surface temperature values were obtained.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.12
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• pp.158-164
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• 2015

Lane detection is one of the key parts among autonomous vehicle technologies because lane keeping and path planning are based on lane detection. Camera is used for lane detection but there are severe limitations such as narrow field of view and effect of illumination. On the other hands, Lidar sensor has the merits of having large field of view and being little influenced by illumination because it uses intensity information. Existing researches that use methods such as Hough transform, histogram hardly handle multiple lanes in the co-occuring situation of lanes and road marking. In this paper, we propose a method based on RANSAC and regularization which provides a stable and precise detection result in the co-occuring situation of lanes and road marking in highway scenarios. This is performed by precise lane point extraction using circular model RANSAC and regularization aided least square fitting. Through quantitative evaluation, we verify that the proposed algorithm is capable of multi lane detection with high accuracy in real-time on our own acquired road data.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.4
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• pp.32-40
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• 2008

Since vision-based surveillance system uses a conventional camera which has a narrow field of view, it is difficult to apply it into the environment whose the ceiling is low and the monitoring area is wide. To overcome this problem, the method of increasing the number of camera causes the increase of the cost and the difficulties of camera set-up For these problems, we propose a new surveillance system based on multiple fisheye cameras which have 180 degree field of view. The proposed method handles occlusions using the homography relation between the multiple fisheye cameras. In the experiment, four fisheye cameras were set up within the area of $17{\times}14m$ at height of 2.5 m and five people wandered and crossed with one another within this area. The detection rates of the proposed system was 83.0% while that of a single camera was 46.1%.

• Journal of the Society of Disaster Information
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• v.12 no.2
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• pp.181-188
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• 2016

Database construction of basic elements for displaying CCTV informations(the location, direction, distance, maximum distance, Tele mode angle view, Wide mode angle view, etc.) is conducted by complete survey about CCTV information in model area. Automatic mapping algorithm is suggested to schematize and visualize it on the basic of the investigated CCTV informations. In the result, the CCTV locations in partial areas are duplicated on about 11 percents. Duplicated ones among twelve CCTVs are total five. If the redesign of CCTV location and direction by displaying the CCTV informations based on the suggested algorithm is performed, it can be used as scientific explanations.

• Journal of IKEEE
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• v.21 no.3
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• pp.248-251
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• 2017

In this paper, The proposed board is developed by EMI compliant Dash Camera with $360^{\circ}$ omni angle. The proposed board is designed by designing DM and CM input noise reduction circuit and applying active EMI filter coupling circuit. The DM and CM input noise reduction circuit design uses a differential op amp circuit to obtain the DM noise coupled to the input signal via the parasitic capacitance(CP). In order to simplify the circuit by applying the active EMI filter coupling circuit, a noise separator is installed to compensate the noise of the EMI source to compensate the CM and DM active filter simultaneously. In order to evaluate the performance of the board for the proposed EMI response, an authorized accreditation body has confirmed that the electromagnetic certification standard for each frequency band is satisfied.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.9
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• pp.590-597
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• 2014

This paper proposes multi-camera system that relies on 3D views for panoramic video and distribution method about panoramic video generation algorithm by using cloud computing. The proposed monitoring system monitors the projected 3D model view, instead of individual 2D views, to detect image distortions. This can minimize compensation errors caused by parallax, thereby improving the quality of the resulting panoramic video. Panoramic video generation algorithm can be divided into registration part and compositing part. Therefore we propose off-loading method of these parts with cloud computing for panoramic video service.

• Korean Journal of Optics and Photonics
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• v.19 no.4
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• pp.276-286
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• 2008

The representative alignments for taking a stereo image by using a stereoscopic camera are the toed-in and the parallel alignment. In this paper, we tried to find important factors in the process that captures the stereo image by modifying parallel type 3D camera alignment to take the same object information as, for instance, when toed-in type was used. The modified parallel type 3D camera has merits in both types. As a result, three important factors are found by simulation to be inter-camera distance, field of view and convergence angle for both types. And the change of the convergence angle is known to be the most important factor at the stereo fusible area in processing. The effective ranges of these factors to simulate perfectly toed-in type by modified parallel type are strongly dependent on a user's circumstances such as mobile, official, theater and so on. Additionally, the error of the simulation is reduced when the focal length of the stereo camera is short and the convergence angle becomes smaller.