• Title/Summary/Keyword: Light filter

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Effective light source-based SNR scalable coding of Digital Hologram (디지털 홀로그램의 효과적인 광원 기반의 SNR 스케일러블 코딩 기법)

  • Kim, Younjoo;Lee, Yoon-Hyuk;Seo, Young-Ho;Kim, Dong-Wook
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2013.06a
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    • pp.77-79
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    • 2013
  • 본 논문에서는 광원 정보를 사용하여 다양한 재생환경에서 효과적인 홀로그래픽 비디오 서비스를 제공하기 위한 방법을 제안한다. 제안하는 기법에서 부호화 과정에서는 가우시안 블러를 적용한 영상의 개수를 조절, 분리 하고 다운 샘플링 한 하나의 영상 압축을 한 뒤 전송한다. 이 영상을 다운 샘플링, 업 샘플링, 보간법, 양방향 필터 (Bi-lateral filter) 등의 기법을 이용하여 획득한 영상과 나머지 영상을 다운 샘플링과 업 샘플링 하여 더한 영상의 차를 압축하여 수신측으로 전송한다. 복호화 과정에서는 압축된 광원 정보를 복원한 후 기본계층 정보를 가진 영상을 업 샘플링과 보간법, 양방향 필터 (Bi-lateral filter) 등의 기법을 적용하고 수신자의 환경과 고려에 따라 차영상을 더 한 후 CGH를 통해 홀로그램을 획득하였다. 실험을 통해 제안하는 기법이 기존의 방법들 보다 우수한 홀로그램을 복원 할 수 있다는 것을 확인하였다.

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Infrared imaging mthod using time division reticle (시간분할 회전격자를 이용한 적외선 영상구성방법)

  • 배장근;김철수;이승희;김정우;조웅호;김수중
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.1
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    • pp.193-199
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    • 1995
  • A novel imaging method in which time-division spinning reticle samples different pixel location of input image in different time is presented. The lens collects the beam passing throughthe reticle to a photodetector. Image reconstruction is accomplished by sampling the detector output corresponding to the spinning speed of reticle. Since the time-division reticle system removed the necessity of bandpass filter bank which has sharp cut-off characteristic, high resolution image is obtained without increasing the number of filter. To confirm the validity of this method, a computer simulation and an optical experiment using visual light are presented.

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Modified Ternary Phase-Only SDF Filter for Korean Character Recognition (한글문자 인식을 위한 수정3차 위상SDF필터)

  • 도양회;김정우;정신일;하영호;김수중
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.8
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    • pp.1262-1269
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    • 1989
  • For the efficient recognition of Korean characters, a modified ternary phase-only synthetic discriminanty function filter(MTPOF-SDF) is proposed. MTPOF-SDF can not only discriminate the true class patterns and the similar, symmetric, or patially included false ones but also recognize the diverse variations in true class patterns due to combinatorial form as the same ones. And scale and rotation-invariant recognition is achieved. To preserve the features of the characters, phase information should be used. And to contsrol phase information easily, ternary quantization of the phase is preferred. Also low resolution requirement is achieved for compatibility with low resulution devices such as spatial light modulators.

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Laser sensor wavelength interrogation using a long-period fiber grating (장주기 격자를 이용한 광섬유 레이저센서의 파장변화 측정)

  • Song, Min-Ho;Lee, Sang-Bae;Choi, Sang-Sam;Nam, Hui;Lee, Byoung-Ho
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.12
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    • pp.83-88
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    • 1997
  • We present a fiber laser sensor that uses a fiber grating as a strain sensor head and an end-reflector of the laser cavity. A passive wavelength. The long-period grating band-rejection filter showed a wide usable filter wavelength range of about 25 nm, and the intensity of transmitted light increased by 16% for 1nm sensor wavelength shift in trhe measurement range.

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Development of a UAV Flight Control System Using a Low Cost GPS/IMU (저가형 GPS/IMU를 이용한 UAV 비행 제어 시스템 개발)

  • Koo, Won-Mo;Chun, Se-Bum;Won, Dae-Hee;Kang, Tae-Sam;Lee, Young-Jae;Sung, Sang-Kyung
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.5
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    • pp.502-510
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    • 2008
  • UAVs(Unmanned Aerial Vehicles) have many applications in military and commercial areas. The flight control system of UAVs is more important than manned aircraft's because the mission of UAVs must be operated without a human pilot. But very heavy and expensive navigation system makes it difficult to develop UAV flight control system. In this research, GPS/IMU integrated navigation filter was developed for light weight/low cost flight control system of small UAVs. With this navigation filter, full flight control system which has real time operating capability has been developed. The performance of the flight control system is basically checked by HILSIM (Hardware In the Loop SIMulation). Finally, the flight control system is verified by showing performance test result under real flight environment.

Tracking a Selected Target among Multiple Moving Objects (다수의 물체가 이동하는 환경에서 선택된 물체의 추적기법)

  • 김준석;송필재;차형태;홍민철;한헌수
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.363-363
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    • 2000
  • The conventional algorithms which identify and follow a moving target using a camera located at a fixed position are not appropriate for applying to the cases o( using mobile robots, due to their long processing time. This paper proposes a new tracking algorithm based on the sensing system which uses a line light with a single camera. The algorithm categirizes the motion patterns of a pair of mobile objects into parallel, branching, and merging motion, to decide of which objects the trajectories should be calculated to follow the reference object. Kalman Filter is used to estimate the trajectories of selected objects. The proposed algorithm has shown in the experiments that the mobile robot does not miss the target in most cases.

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Spacecraft Attitude Determination Algorithm Using Magnetometer (자장계를 이용한 인공위성의 자세결정 알고리즘)

  • 민현주;김인중;김진호;박춘배;용기력;이승우
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.342-342
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    • 2000
  • We present 3-axis stabilized spacecraft attitude determination algorithm using the magnetometer. The magnetometer has been used as a reliable, light-weight and inexpensive sensor in attitude determination and reaction wheel momentum dumping system. Recent studies have attempted to use the magnetometer when other attitude sensor, such as star tracker, fails. The differences between the measured and computed the Earth's magnetic field components are spacecraft attitude errors. In this paper, we propose extended Kalman filter(EKF) to determine spacecraft attitude with the magnetometer data and gyro-measured body rates. We develop and simulate this algorithm using MATLAB/SIMULINK. This algorithm can be used as a backup attitude determination system.

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Surface Defect Inspection System for Hot Slabs (열간 슬라브 표면결함 탐상 시스템)

  • Yun, Jong Pil;Jung, Daewoong;Park, Changhyun
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.8
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    • pp.627-632
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    • 2016
  • In this paper, we propose a new vision-based defect inspection system for the surface of hot slabs. To minimize the influence of self-emission from slab surfaces with high temperature, an optic method based on blue LED light and a blue pass filter is proposed. Because the slab surface is partially covered with scales, which are unavoidable oxidized substances caused during manufacturing, it is difficult to distinguish between vertical cracks and scale. In order to resolve this problem and to improve the detection performance, the use of a Gabor filter and dynamic programming are proposed. Finally, the effectiveness of the proposed method is shown by means of experiments conducted on images of hot slabs that were obtained from an actual slab production line.

Perceptual Fusion of Infrared and Visible Image through Variational Multiscale with Guide Filtering

  • Feng, Xin;Hu, Kaiqun
    • Journal of Information Processing Systems
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    • v.15 no.6
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    • pp.1296-1305
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    • 2019
  • To solve the problem of poor noise suppression capability and frequent loss of edge contour and detailed information in current fusion methods, an infrared and visible light image fusion method based on variational multiscale decomposition is proposed. Firstly, the fused images are separately processed through variational multiscale decomposition to obtain texture components and structural components. The method of guided filter is used to carry out the fusion of the texture components of the fused image. In the structural component fusion, a method is proposed to measure the fused weights with phase consistency, sharpness, and brightness comprehensive information. Finally, the texture components of the two images are fused. The structure components are added to obtain the final fused image. The experimental results show that the proposed method displays very good noise robustness, and it also helps realize better fusion quality.

Preparation of Colour Filter Photo Resists for Improving Colour Purity in Liquid Crystal Displays by Synthesis of Polymeric Binder and Treatment of Pigments

  • Yoon, Chun;Choi, Jae-Hong
    • Bulletin of the Korean Chemical Society
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    • v.30 no.8
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    • pp.1821-1826
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    • 2009
  • Liquid crystal display (LCD) devices contain a colour filter which can visualise colour images by transmitting or absorbing light. Colour properties of LCD mainly depend on colour materials such as pigments and polymeric binders. In this paper, colour properties were studied to improve colour quality of LCD. Generally, the colour properties can be classified into three categories which are colour purity, brightness and contrast ratio. For this study, photo resists were prepared by treatment of pigments and synthesis of polymeric binder. The treated pigments were dispersed and formulated with additives for preparing a photo resist that could be used for manufacturing colour filters. As a result of what we studied, type, mixture ratio and concentration of pigments were very important to improve colour purity of LCD device.