• Title, Summary, Keyword: Optical correlator

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Evauation for Optical Visual Cryptography Encryption by using Optical Correlator (광상관기를 이용한 광 시각 암호의 암복호 평가)

  • 이상이;류충상;류대현;이승현;김은수
    • Proceedings of the IEEK Conference
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    • pp.71-74
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    • 2001
  • Optical visual cryptography was proposed by conjunction of the optical theory with the cryptography. However, it had some difficulties. The problems occurred in the process of transferring data processing system from visual to optics. Therefore, it is appropriate to approach these problems in terms of optics. The results show that the optical visual cryptography system has both the effectiveness and reliability as well as real-time implementation property.

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An optical encryption system for Joint transform correlator (JTC 구조를 이용한 광학적 영상 암호화 시스템)

  • 박세준;서동환;이응대;김종윤;김정우;이하운;김수중
    • Proceedings of the IEEK Conference
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    • pp.63-66
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    • 2001
  • In this paper a binary image encryption technique and decryption system based on a joint transform correlator (JTC) are Proposed. In this method, a Fourier transform of the encrypted image is used as the encrypted data and a Fourier transform of the random phase is used as the key code. The original binary image can be reconstructed on a square law device, such as a CCD camera after the joint input is inverse Fourier transformed. The proposed encryption technique does not suffer from strong auto-correlation terms appearing in the output plane. Based on computer simulations, the proposed encryption technique and decoding system were demonstrated as adequate for optical security applications.

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Volume Holographic Fingerprint Recognition System for Personal Identification (개인 인증을 위한 체적 홀로그래픽 지문인식 시스템)

  • 이승현
    • Journal of the Korean Society of Safety
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    • v.13 no.4
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    • pp.256-263
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    • 1998
  • In this paper, we propose a volume holographic fingerprint recognition system based on optical correlator for personal identification. Optical correlator has high speed and parallel processing characteristics of optics. Matched filters are recorded into a volume hologram that can store data with high density, transfer them with high speed, and select a randomly chosen data element. The multiple reference images of database are prerecorded in a photorefractive crystal in the form of Fourier transform images, simply by passing the image displayed in a spatial light modulator through a Fourier transform lens. The angular multiplexing method for multiple holograms of database can be achieved by rotating the crystal by use of a step motor. Experimental results show that the proposed system can be used for the security verification system.

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Joint-transform Correlator Multiple-image Encryption System Based on Quick-response Code Key

  • Chen, Qi;Shen, Xueju;Cheng, Yue;Huang, Fuyu;Lin, Chao;Liu, HeXiong
    • Current Optics and Photonics
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    • v.3 no.4
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    • pp.320-328
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    • 2019
  • A method for joint-transform correlator (JTC) multiple-image encryption based on a quick-response (QR) code key is proposed. The QR codes converted from different texts are used as key masks to encrypt and decrypt multiple images. Not only can Chinese text and English text be used as key text, but also symbols can be used. With this method, users have no need to transmit the whole key mask; they only need to transmit the text that is used to generate the key. The correlation coefficient is introduced to evaluate the decryption performance of our proposed cryptosystem, and we explore the sensitivity of the key mask and the capability for multiple-image encryption. Robustness analysis is also conducted in this paper. Computer simulations and experimental results verify the correctness of this method.

Moving Target Tracking System using Optical BPEJTC (광 BPEJTC를 이용한 이동표적 추적시스템)

  • 김은수
    • Proceedings of the Optical Society of Korea Conference
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    • pp.105-116
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    • 1995
  • In this paper, we propose a new a new EOST by using the optical JTC(joint transform correlator) as the feature extraction park, because the JTC can adaptively detect the relative displacements of moving targest. Firstly, we derive the BPEJCT(binary phase extraction JTC) which is a phase type JTC and can remove the intracless correlation peaks of the conventional JTC. Then, especially we hardware construction for driving the BPEJTC in real, and with the Kalman target estimation alogorithm, we carried out a target tracking experiment only to show the possibility of real-time implementation of the EOST.

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Optical implementation of 3D image correlator using integral imaging technique (집적영상 기술을 이용한 3D 영상 상관기의 광학적 구현)

  • Piao, Yongri;Kim, Seok-Tae;Kim, Eun-Soo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.8
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    • pp.1659-1665
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    • 2009
  • In this paper, we propose an implementation method of 3D image correlator using integral imaging technique. In the proposed method, elemental images of the reference and signal 3D objects are recorded by lenslet arrays and then reference and signal output plane images with high resolution are optically reconstructed on the output plane by displaying these elemental images into a display panel. Through cross-correlations between the reconstructed reference and the single plane images, 3D object recognition is performed. The proposed method can provide a precise 3D object recognition by using the high-resolution output plane images compared with the previous methods and implement all-optical structure for real-time 3D object recognition system. To show the feasibility of the proposed method, optical experiments are carried out and the results are presented.

The Characteristics and Optical Implementation of OA-pSDF BPOF (OA-pSDF BPOF의 특성 및 광학적 구현)

  • 임종태;박성균;엄주욱;박한규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.8
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    • pp.1433-1445
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    • 1994
  • In this paper, an coherent optical correlator system based on the off-axis projection synthetic discriminant funtion (OA-pSDF) was analyzed and implemented optically. The filter was synthesized by combining conventional pSDF with single reference plane wave multiplexing. Synthesized pSDF were transformed to binary phase only filters (BPOFs) and fabricated as computer generated holograms(CGHs), which was used in the real time optical correlator system instead of using expensive spatial light modulators(SLMs). From the characteristic test, it was found that OA-pSDF showed distortion invariance and good performances in discrminating subset images. The proposed OA-pSDF BPOF could overcome the limitations of conventional BPOFs : that is distortion variance such as acale and rotation, especially out of plane variance.

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Image Encryption and Decryption System using Optical Correlator and Iterative Algorithm (광 상관기와 반복 알고리듬을 이용한 영상 암호화 및 복호화 시스템)

  • 김철수;조창섭
    • Proceedings of the Optical Society of Korea Conference
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    • pp.64-65
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    • 2003
  • 현대 정보화 사회에서는 컴퓨터 시스템 및 통신 시스템의 결합으로 시공간을 초월하여 엄청난 양의 정보교환이 신속히 이루어지고 다양한 형태의 서비스 환경이 창출되어 사회 전반에 걸쳐 빠르게 확산됨에 따라 경제, 사회 등 전 분야에 큰 변화를 일으키고 있다. 이러한 사회는 우리생활을 보다 편리하게 만들어 주고 있지만 때로는 정보의 유출로 인한 막대한 피해를 주기도 하여서 정보보호가 매우 중요한 문제로 대두된다. (중략)

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Nonlinear 3D image correlator using computational integral imaging reconstruction method (컴퓨터 집적 영상 복원 방법을 이용한 비선형 3D 영상 상관기)

  • Shin, Dong-Hak;Hong, Seok-Min;Kim, Kyoung-Won;Lee, Byung-Gook
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.155-157
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    • 2012
  • In this paper, we propose a nonlinear 3D image correlator using computational reconstruction of 3D images based on integral imaging. In the proposed method, the elemental images for reference 3D object and target 3D object are recorded through the lens array. The recorded elemental images are reconstructed as reference plane image and target plane images using the computational integral imaging reconstruction algorithm and the nonolinear correlation between them is performed for object recognition. To show the usefulness of the proposed method, the preliminary experiments are carried out and the experimental results are presented compared with the conventional results.

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A Study on the Test Results and Implementation of Correlated Result Saving System using the Gluster File System (Gluster 파일시스템을 이용한 상관자료 수집 시스템 구축 및 시험고찰)

  • Yeom, Jae-Hwan;Oh, Se-Jin;Roh, Duk-Gyoo;Jung, Dong-Kyu;Hwang, Ju-Yeon;Oh, Chungsik;Kim, Hyo-Ryoung
    • Journal of the Institute of Convergence Signal Processing
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    • v.17 no.2
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    • pp.53-60
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    • 2016
  • In this paper, we introduce the implementation and test results of a new method of correlated result storage to achieve the full performance of the Daejeon hardware correlator. Recently, the observation of 8 Gbps speed, which is the maximum observational standard of KVN(Korean VLBI Network), has been performed. The correlation processing using the Daejeon hardware correlator is also required. Therefore, a new correlation result storage introduction has become necessary. The maximum correlation result output speed of the Daejeon hardware correlator is 1.4 GB/sec per 25.6 ms integration time. The conventional correlation result storage system can not cope with the maximum correlation output speed of the Daejeon hardware correlator, and the output speed is limited to 1/4. That is, among the four input ports of the Daejeon hardware correlator, the three inputs are limited to correspond to the observation rate of 1 Gbps. This new storage system uses the Gluster file system among many of the latest technologies used in storage systems. In tests that meet the maximum output rate of 1.4 GB/sec for the Daejeon hardware correlator, 350 MB/sec for each of the four optical outputs, resulting in 1.4 GB/sec in total.