• Title, Summary, Keyword: Optical correlator

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3-D Object Tracking using 3-D Information and Optical Correlator in the Stereo Vision System (스테레오 비젼 시스템에서 3차원정보와 광 상관기를 이용한 3차원 물체추적 방법)

  • 서춘원;이승현;김은수
    • Journal of Broadcast Engineering
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    • v.7 no.3
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    • pp.248-261
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    • 2002
  • In this paper, we proposed a new 3-dimensional(3-D) object-tracking algorithm that can control a stereo camera using a variable window mask supported by which uses ,B-D information and an optical BPEJTC. Hence, three-dimensional information characteristics of a stereo vision system, distance information from the stereo camera to the tracking object. can be easily acquired through the elements of a stereo vision system. and with this information, we can extract an area of the tracking object by varying window masks. This extractive area of the tracking object is used as the next updated reference image. furthermore, by carrying out an optical BPEJTC between a reference image and a stereo input image the coordinates of the tracking objects location can be acquired, and with this value a 3-D object tracking can be accomplished through manipulation of the convergence angie and a pan/tilt of a stereo camera. From the experimental results, the proposed algorithm was found to be able to the execute 3-D object tracking by extracting the area of the target object from an input image that is independent of the background noise in the stereo input image. Moreover a possible implementation of a 3-D tele-working or an adaptive 3-D object tracker, using the proposed algorithm is suggested.

Optical Security System Based on the Phase Characteristic of Joint Transform Correlator (결합변환 상관기의 위상특성을 이용한 광 암호화 시스템)

  • 박세준;서동환;김수종
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.40 no.6
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    • pp.400-407
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    • 2003
  • In this paper an optical encryption system, which can decrypt the original image by using the autocorrelation terms of a JTC, is proposed. Unlike the classical JTC, the joint input plane of the proposed system is composed in a frequency domain not a spatial domain, thus it needs only one Fourier transformation. To use like this, the phase component appeared in the output plane of JTC should be considered. We presents the effect of phase and provides the solution. An original image is encrypted to a complex-valued random image. The original image is reconstructed using the autocorrelation terms which is the main drawback of JTC, therefore the proposed system is more suitable for JTC and real time processing. By computer simulation and optical experiment, the analysis for the phase effect and the performance of the proposed system are confirmed.

Fabrication of Magneto-Optic Spatial Light Modulator based on 1D Magnetophotonic Crystal (MPC-MOSLM) (1차원 자성 포토닉 결정을 이용한 자기 광학 공간 광 변조기의 제조)

  • ;;Misuteru Inoue;Hideyoshi Horimai
    • Proceedings of the Optical Society of Korea Conference
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    • pp.192-193
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    • 2000
  • 공간 광변조기(spatial light modulator)는 빛의 진폭, 위상 혹은 편광 상태를 공간적으로 변조하는 소자이다. 2차원적인 화소 배열을 갖는 공간 광 변조기는, 전자 소자들이 지니지 않는, 정보를 고속으로 병렬 처리할 수 있는 기능에 힘입어, 광상관기, 광컴퓨터, 프로젝션 TV, 빔 프로젝트, 홀로그래피 메모리의 핵심 소자로 지난 50년간 활발히 연구되어, 액정 공간 광 변조기, 자기 광학 공간 광 변조기$^{(1)(2)}$ 등이 개발되었다. 이 중에서 자기광학 공간 괌 변조기는 화소의 스위칭 스피드가 빠르고, 견고하고, 내방사능성을 가질 뿐만 아니라, 비휘발성이라는 장점을 가지고 있어, 주로 우주항공용의 Miniature Ruggedized Optical Correlator(MROC)$^{(3)}$ 에 사용되어 왔다. 본 논문에서는 새로운 개념의 공간 광 변조기인 자성 포토닉 결정을 이용한 자기 광학 공간 광 변조기(MPC-MOSLM)의 제조에 관하여 논하고자 한다 (중략)

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A Study on the Optical Correlation Characteristics for the fSDF/POF, BPOF Spatial Matched Filters (fSDF/POF, BPOF 공간 정합 필터의 광 상관 특성에 관한 연구)

  • Seok Hee Jeon
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.7
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    • pp.48-55
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    • 1992
  • In this paper, fSDF/POF, BPOF spatial matched filters are designed and implemented by CGH. The correlation characteristics for the suggested filters are analyzed for the distorted input images. Input patterns are obtained from the out-of-plane aircraft images by gradually rotating it, and then used for SDF training images. Modified version of LCD is used for a real-time input device of an optical correlator, and CGH-based fSDF filters are fabricated on film mask for spatial matched filter in order to recognize the distorted images. Total optical corrlator system size is effectively reduced to 148.8 cm by using lens combinations. Computer simulations and experimental results show that the suggested phase filters have nearly uniform correlation characteristics and have good classification capabilities between two classes.

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Korean Character Recognition Using Optical Associative Memory (광 연상 기억 장치를 이용한 한글 문자 인식)

  • 김정우;배장근;도양회
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.6
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    • pp.61-69
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    • 1994
  • For distortion-invariant recognition of Korean characters, a holographic implementation of an optical associative memory system is proposed. The structure of the proposed system is a single-layer neural network employing interconneclion matrix, thresholding and feedback. To provide the interconnection matrix, we use two CGII's which are placed on intermcdiate plane of cascaded Vander Lugt corrclators to form an optical memory loop. The holographic correlator stores reference images in a hologram and retrives them in a coherently illuminated feedback loop. An input image which maybe noisy or incomplete, is applicd to the system and simultaneously correlated optically with all of the stord images. These correlations are throsholed and fed back to the input, where the strongest correlation reinforces the input image. The enhanced image passes arround the loop repeatedly, approaching the stored image more closely on each pass until the system stabilizes on the desired image. The computer simulation results show that the proposed Korean Character recognition algorithm has high discrimination capability and noise immunity.

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Design and development of VSI Optical Adapter for high speed transmission of VLBI observation data (VLBI 관측데이터 초고속 전송을 위한 VSI 광변환 송수신 장치의 설계 및 개발)

  • Oh, Se-Jin;Roh, Duk-Gyoo;Yeom, Jae-Hwan;Jung, Jin-Seung;Jung, Dong-Kyu;Oh, Chung-Sik;Ozeki, Kensuke;Onuki, Hirofumi;Harada, Keniichi
    • Journal of the Institute of Convergence Signal Processing
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    • v.14 no.4
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    • pp.261-269
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    • 2013
  • This paper describes the design and development of VSI (VLBI standard interface) optical adapter for transmitting VLBI(Very long baseline interferometry) observation data with optical signal. VSI cable comprised of 80-line is being used for observed data transmission with maximum length of 5-meter between playbacks (Mark5B, VERA2000) and raw VLBI data buffer (RVDB), RVDB and VLBI correlation subsystem (VCS) in Daejeon correlator. It has a plan to conduct the data processing for 16-stations and introduce the 14 RVDB systems in near future. And data loss frequently occurred because of trouble of VSI cable MDR80 connector. By considering the data loss by connector error of VSI cable, RVDB system extension plan, effective space usage and long distance data transmission(e-VLBI), the VSI optical adapter was proposed and developed for effectively transmitting and receiving VLBI data through optical signal. In order to confirming the performance of developed VSI optical adapter, the experiments for data transmission was conducted between playback and RVDB system, and confirmed that data transmission was clearly done without any data loss.

DATA ACQUISITION SYSTEM OF THE SOFT

  • Moon, Yong-Jae;Park, Young-Deuk;Jang, Be-Ho;Sim, Kyung-Jin;Yun, Hong-Sik;Kim, Jung-Hoon
    • Publications of The Korean Astronomical Society
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    • v.11 no.1
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    • pp.243-250
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    • 1996
  • Data acquisition system mounted on the Solar Flare Telescope at Bohyunsan Optical Astronomy Observatory is briefly described. The system is made up with CCD cameras, an image processor, a PCI-type PC and a SUN workstation. The image processor, MVC 150/40 comprises a variable scan acquisition module, an image manager and a binary correlator computational module. A typical polarization image of a sunspot is presented to demonstrate performance of the system.

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Optical encryption and decryption technique using virtual image in frequency domain (가상 영상을 이용한 주파수 영역에서의 광학적 암호화 및 복호화 방법)

  • 서동환;조규보;박세준;김수중;김정우;노덕수
    • Korean Journal of Optics and Photonics
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    • v.14 no.3
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    • pp.255-259
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    • 2003
  • In this paper, we propose an improved image encryption and decryption method using a virtual image and a joint transform correlator (JTC). The encrypted image is obtained by the Fourier transform of the product of a virtual-phase image and a random-phase image, and a Fourier transform of the decrypting key generated by the proposed phase assignment rule is used as the Fourier decrypting key. Based on the solution, the original image is reconstructed using JTC in the frequency-domain. The proposed method using a virtual image, which does not contain any information from the original image, prevents the possibility of counterfeiting by unauthorized people. And also the auto-correlation terms, which are the drawback of a JTC system, contribute to reconstructing the original image rather than to disturbing its identification. But because phase-only encryptions are sensitive to noise and scratches, phase errors can be generated in fabricating the encrypted image or the Fourier decrypting key so the errors that are responsible for degradation of the quality of the reconstructed image are analyzed and the solution is demonstrated. Computer simulations show the solution, and the proposed method is very useful for JTC architecture.

A study on correlation-based fingerprint recognition method (광학적 상관관계를 기반으로 하는 지문인식 방법에 관한 연구)

  • 김상백;주성현;정만호
    • Korean Journal of Optics and Photonics
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    • v.13 no.6
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    • pp.493-500
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    • 2002
  • Fingerprint recognition is concerned with fingerprint acquisition and matching. Our research was focused on a fingerprint matching method using an inkless fingerprint input sensor at the fingerprint acquisition step. Since an inkless fingerprint sensor produces a digital-image-processed fingerprint image, we did not consider noise that can happen while acquiring the fingerprint. And making the user attempt fingerprint input as random, we considered image distortion that translation and rotation are included as complex. NJTC algorithm is used for fingerprint identification and verification. The method to find the center of the fingerprint is added in the NJTC algorithm to supplement discrimination of fingerprint recognition. From this center point, we decided the optimum cropping size for effective matching with pixels and demonstrated that the proposed method has high discrimination and high efficiency.