• Journal of the Institute of Convergence Signal Processing
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• v.3 no.2
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• pp.7-14
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• 2002

This paper proposes a camera motion estimation technique using special relations of motion vectors of geometrically symmetrical triple points of two consecutive views of single camera. The proposed technique uses camera-induced motion vectors and their relations other than feature points and epioplar constraints. As contrast to the time consuming iterations or numerical methods in the calculation of E-matrix or F-matrix induced by epipolar constraints, the proposed technique calculates camera motion parameters such as panning, tilting, rolling, and zooming at once by applying the proposed linear equation sets to the motion vectors. And by devised background discriminants, it effectively reflects only the background region into the calculation of motion parameters, thus making the calculation more accurate and fast enough to accommodate MPEG-4 requirements. Experimental results on various types of sequences show the validity and the broad applicability of the proposed technique.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.8
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• pp.60-70
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• 2000

In this paper a 3D position measuring device that finds the 3D position of an arbitarily placed object using a camersa system is introduced. The camera system consists of three stepping motors and a CCD camera and a laser. The viewing direction of the camera is controlled by two stepping motors (pan and tilt motors) and the direction of a laser is also controlled by a stepping motors(laser motor). If an object in a remote place is selected from a live video image the x,y,z coordinates of the object with respect to the reference coordinate system can be obtained by calculating the distance from the camera to the object using a structured light scheme and by obtaining the orientation of the camera that is controlled by two stepping motors. The angles o f stepping motors are controlled by a SGI O2 workstation through a parallel port. The mathematical model of the camera and the distance measuring system are calibrated to calculate an accurate position of the object. This 3D position measuring device can be used to acquire information that is necessary to monitor a remote place.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.31-35
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• 2008

Purpose: This study is to design a triplet optical system for CCTV camera lens. Methods: It was a telescopic lens with $5^{\circ}$ field angle, 56 mm focal length, 20 mm diameter, and 2/3 inches sized CCD array detector. Results: The performance of the subject optical system was evaluated by applying ray fan, spot diagram, and diffraction optical MTF. The wavelength was achromatized at Fraunhofer C, d and F-line, and both MTF and tangential & sagittal MTF shows more than 70% at spatial frequency of 50 linepairs/mm. Conclusions: The marketable triplet optical system for CCTV camera was designed and its utility was considered.

• Journal of Astronomy and Space Sciences
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• v.11 no.2
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• pp.320-326
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• 1994

The KITSAT-1 (Auguse, 1992) and the KITSAT-2(September, 1993) were successfully launched and operated by the SatRec(Satellite Research Center). Both carry the CCD cameras to monitor the image of the earth. We used the camera bench type automatic equipment in the KSRI(Korea Standards Research Institute) to measure the MTF(Modulation Transfer Function) value of the lens attached to the CCD camera. We measured the tangential MTF and the sagital MTF by varing the f-number and the field angle. According to the result, the light from a point source is focused within one pixel of the CCD chip when the f-number is smaller than 4.0, and the MTF value becomes smaller as the field angle increases.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.11a
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• pp.240-241
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• 2011

자연스러운 3D 실감영상을 감상하기 위해서는 많은 시점의 영상이 필요하며 과거 스테레오 디스플레이 장치로부터 최근 그 시점 수가 크게 늘어난 디스플레이 장치로 기술 발전이 이뤄지고 있으며 이에 따라 다시점 콘텐츠를 생성하기 위한 다양한 기술이 개발되어 있다. 다시점 콘텐츠를 생성하기 위하여 ToF 카메라 및 적외선 패턴을 이용한 방법이 주로 이용되고 있으며 이를 활용한 다시점 콘텐츠 생성을 하는 시도가 이뤄지고 있다. ToF 카메라는 PMD사의 제품 및 SwissRanger 사의 제품이 대표적이며 적외선 패턴을 이용한 방식은 MS사의 Kinect가 대표적이며 본 제품들을 활용한 기술 비교를 통하여 다시점 콘텐츠 생성의 결과 및 이를 비교한 장단점을 구분하였다. PMD사의 ToF 카메라는 두 개 이상의 광원을 사용하여 Depth 추출시에 Hole 영역의 크기가 작으나 ToF 영상의 해상도가 매우 작아 고화질의 콘텐츠를 생성하기 위하여 별도의 영상처리 알고리즘이 요구되었다. 반면 MS사의 Kinect는 Depth 영상의 해상도가 상대적으로 커서 영상처리 알고리즘의 복잡도가 작아지나 Depth 추출을 위한 카메라와 RGB 카메라의 위치가 공간적으로 떨어져 있어 이를 보정하기 위한 알고리즘이 요구되며 다시점 변환시 화질에 있어 상대적으로 떨어지는 것으로 나타났다.

• Korean Journal of Optics and Photonics
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• v.29 no.4
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• pp.149-158
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• 2018

A generalized structural design equation can be used to simplify and systematize a telecentric lens system composed of multiple lenses, as a creative design method of the authors. Through this structural equation, we have investigated the feasibility and design methodology of a telecentric lens equipped with a conventional smartphone camera for machine vision. As a result, we could verify and present a useful, generalized structural equation termed the $f{\theta}$ formula, being able to divide and combine the whole telecentric lens system into two modularized lens groups.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.499-506
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• 2022

For autonomous ships to be commercialized and be able to navigate in coastal water, they must be able to detect maritime obstacles. One of the most common obstacles seen in coastal area are the farm buoys. In this study, a maritime object detection system was developed that detects buoys using the YOLO algorithm and visualizes the distance and bearing between buoys and the ship through geometric interpretation of camera images. After training the maritime object detection model with 1,224 pictures of buoys, the precision of the model was 89.0%, the recall was 95.0%, and the F1-score was 92.0%. Camera calibration had been conducted to calculate the distance and bearing of an object away from the camera using the obtained image coordinates and Experiment A and B were designed to verify the performance of the maritime object detection system. As a result of verifying the performance of the maritime object detection system, it can be seen that the maritime object detection system is superior to radar in its short-distance detection capability, so that it can be used as a navigational aid along with the radar.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.06a
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• pp.137-144
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• 2010

Ground digital image data obtained by using DSLR camera can be used to the ground photogrammetry and spatial modeling. Intensity of each pixel in digital video images is the most important parameter to generate digital image. Therefore, it is needed to estimate the parameters and spectral characteristics of digital cameras in order to take more definite intensity data. In this study, using the Sony DSC-F828 DSLR camera, seven digital images are obtained by the continuous shooting. (frame rate, 0.38 seconds). And then extract the value of the intensity from RGB band of each digital color photographs to confirm difference of intensity between frames. The purpose of this study is to confirm spectral characteristics and changes and to estimate correlation through the analysis of statistical in each pixel of R, G, B band.

• Korean Journal of Optics and Photonics
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• v.28 no.5
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• pp.241-249
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• 2017

This paper presents the design and evaluation of the optical system for an uncooled thermal-imaging camera. The operating wavelength range of this system is from $7.7{\mu}m$ to $12.8{\mu}m$. Through optimization, we have obtained a LWIR (Long Wave Infrared) optical system with a focal length of 5.44 mm, which consists of four aspheric surfaces and two diffractive surfaces. The f-number of the optical system is F/1.2, and its field of view is $90^{\circ}{\times}67.5^{\circ}$. The hybrid lens was used to balance the higher-order aberrations, and its diffraction properties were evaluated by scalar diffraction theory. We calculated the polychromatic integrated diffraction efficiency, and the MTF drop generated by background noise. We have evaluated the thermal compensation of a LWIR fixed optical system, which is optically passively athermalized to maintain MTF performance in the focal depth. In conclusion, these design results are useful for an uncooled thermal-imaging camera.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.1073-1075
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• 2019

최근 VR/AR, 자율주행차 등 다양한 응용분야가 주목 받으며 Time of Flight (ToF) 카메라와 같은 사물과 카메라 간의 거리를 측정할 수 있는 3D 카메라를 활용한 연구가 활발히 진행되고 있다. 정확한 영상 정보를 획득하기 위해, ToF 카메라 센서에 의해 발생할 수 있는 노이즈를 모델링하는 것은 필수적이다. 본 논문에서 우리는 ToF 카메라 센서에 의해 발생하는 노이즈를 모델링하기 위해 Skellam 분포를 도입한다. 연속하는 거리 영상의 픽셀 차에 대한 분포를 분석함으로써 Skellam 분포 적용의 타당성을 제시한다. ToF 카메라의 노이즈 모델링을 통해 ToF 카메라 센서에 발생하는 노이즈를 제거하고 출력 영상의 품질을 향상시킬 것으로 기대한다.