• Title, Summary, Keyword: Optical Image

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Image Encryption Using Phase-Based Virtual Image and Interferometer

  • Seo, Dong-Hoan;Kim, Soo-Joong
    • Journal of the Optical Society of Korea
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    • v.6 no.4
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    • pp.156-160
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    • 2002
  • In this paper, we propose an improved optical security system using three phase-encoded images and the principle of interference. This optical system based on a Mach-Zehnder interferometer consists of one phase-encoded virtual image to be encrypted and two phase-encoded images, en-crypting image and decrypting image, where every pixel in the three images has a phase value of '0'and'$\pi$'. The proposed encryption is performed by the multiplication of an encrypting image and a phase-encoded virtual image which dose not contain any information from the decrypted im-age. Therefore, even if the unauthorized users steal and analyze the encrypted image, they cannot reconstruct the required image. This virtual image protects the original image from counterfeiting and unauthorized access. The decryption of the original image is simply performed by interfering between a reference wave and a direct pixel-to-pixel mapping image of the en crypted image with a decrypting image. Computer simulations confirmed the effectiveness of the proposed optical technique for optical security applications.

Optical Resonance-based Three Dimensional Sensing Device and its Signal Processing (광공진 현상을 이용한 입체 영상센서 및 신호처리 기법)

  • Park, Yong-Hwa;You, Jang-Woo;Park, Chang-Young;Yoon, Heesun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.763-764
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    • 2013
  • A three-dimensional image capturing device and its signal processing algorithm and apparatus are presented. Three dimensional information is one of emerging differentiators that provides consumers with more realistic and immersive experiences in user interface, game, 3D-virtual reality, and 3D display. It has the depth information of a scene together with conventional color image so that full-information of real life that human eyes experience can be captured, recorded and reproduced. 20 Mega-Hertz-switching high speed image shutter device for 3D image capturing and its application to system prototype are presented[1,2]. For 3D image capturing, the system utilizes Time-of-Flight (TOF) principle by means of 20MHz high-speed micro-optical image modulator, so called 'optical resonator'. The high speed image modulation is obtained using the electro-optic operation of the multi-layer stacked structure having diffractive mirrors and optical resonance cavity which maximizes the magnitude of optical modulation[3,4]. The optical resonator is specially designed and fabricated realizing low resistance-capacitance cell structures having small RC-time constant. The optical shutter is positioned in front of a standard high resolution CMOS image sensor and modulates the IR image reflected from the object to capture a depth image (Figure 1). Suggested novel optical resonator enables capturing of a full HD depth image with depth accuracy of mm-scale, which is the largest depth image resolution among the-state-of-the-arts, which have been limited up to VGA. The 3D camera prototype realizes color/depth concurrent sensing optical architecture to capture 14Mp color and full HD depth images, simultaneously (Figure 2,3). The resulting high definition color/depth image and its capturing device have crucial impact on 3D business eco-system in IT industry especially as 3D image sensing means in the fields of 3D camera, gesture recognition, user interface, and 3D display. This paper presents MEMS-based optical resonator design, fabrication, 3D camera system prototype and signal processing algorithms.

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Image encryption using phase-based virtual image and interferometer

  • Seo, Dong-Hoan;Shin, Chang-Mok;Kim, Jong-Yun;Bae, Jang-Keun;Kim, Jeong-Woo;Kim, Soo-Joong
    • Proceedings of the IEEK Conference
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    • pp.631-634
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    • 2002
  • In this paper, we propose an improved optical security system using three phase-encoded images and the principle of interference. This optical system based on a Mach-Zehnder interferometer consists of one phase-encoded virtual image to be encrypted and two phase-encoded images, encrypting image and decrypting image, where every pixel in the three images has a phase value of '0' and '$\pi$'. The proposed encryption is performed by the multiplication of an encrypting image and a phase-encoded virtual image which dose not contain any information from the decrypted image. Therefore, even if the unauthorized users steal and analyze the encrypted image, they cannot reconstruct the required image. This virtual image protects the original image from counterfeiting and unauthorized access.. The decryption of the original image is simply performed by interfering between a reference wave and a direct pixel-to-pixel mapping image of the encrypted image with a decrypting image. Both computer simulations and optical experiments confirmed the effectiveness of the proposed optical technique for optical security applications.

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Standardized Description Method of Optical Characteristics Tests for Image Sensor Modules (이미지 센서 모듈의 광학적 특성 테스트를 위한 표준화된 기술 방법)

  • Lee, Seongsoo
    • Journal of IKEEE
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    • v.18 no.4
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    • pp.603-611
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    • 2014
  • When image sensor and lens are fixed on the module, mechanical errors often induce tilt, rotation, or narrow field-of-view of the acquired image. Therefore, the optical characteristics of image sensor modules should be tested by test equipments. This paper explains how to test the optical characteristics of images sensors. It also proposes the standardized description methods of optical characteristics tests which are similar with those of image acquisition characteristics tests. The proposed method helps the test equipments to perform image acquisition characteristics tests and optical characteristics tests together.

A Study on the Retina shaped Optical Path Shift Using the Prism

  • Kwon Yun Jung;Nam Sang Yep;Lee Sung Chang
    • Proceedings of the IEEK Conference
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    • pp.699-702
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    • 2004
  • This paper discusses about the mechanism of catching an image through an optical manipulation of each organizations in the eye, more specifically, mechanism of catching an image on a retina through a Camera and a Crystal Lens. In the retina, the macula roles as a fovea contrails and it leads the image which is about 3 mm to be shaped on there. However, even the macula may not properly function, our eyes still can catch the image by shifting the optical path to around of the macula, even if the sensitivity of the image is generally lower than the image on the macula. This paper proposes a method of shifting the shaped image on the retina by refracting the optical path through a prism located on the rear of a screen which consists of a 0.7' TFT LCD. Applying this method that throwing an image around on the macula, central visual disturbance patients among retinitis pimentos patients can expect to recover such a mechanism to catch an image.

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Development of Vision Inspector for Simulating Image Acquisition in Automated Optical Inspection System (Automated Optical Inspection 시스템의 이미지 획득과정을 전산모사하는 Vision Inspector 개발)

  • Jeong, Sang-Cheol;Go, Nak-Hun;Kim, Dae-Chan;Seo, Seung-Won;Choe, Tae-Il;Lee, Seung-Geol
    • Proceedings of the Optical Society of Korea Conference
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    • pp.403-404
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    • 2008
  • This report described the development of Vision Inspector program which can simulate numerically the image acquisition process of Machine Vision System for automatic optical inspection of any products. The program consists of an illuminator, a product to be inspected, and a camera with image sensor, and the final image obtained by ray tracing.

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The development of automatic optical aligner with using the image processing (Image Processing을 이용한 자동 광 정렬 장치 개발)

  • Um, Chul;Kim, Byung-Hee;Kim, Sung-Geun;Choi, Young-Seok
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.536-539
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    • 2002
  • In this paper, we developed the automatic optical fiber aligner by image processing and automatic loading system. Optical fiber is indispensable for optical communication systems that transmit large volumes of data at high speed, but super-precision technology in sub-micron units is required for optical axis adjustment, we have developed 6-axis micro stage system for I/O optical fiber arrays, the initial automatic aligning system/software for a input optical array by the image processing technique, fast I/O-synchronous aligning strategy, the automatic loading/unloading system and the automatic UV bonding mechanism. In order to adjust the alignment it used on PC based motion controller, a $10\mu\textrm{mm}$ repeat-detailed drawing of automatic loading system is developed by a primary line up for high detailed drawing. Also, at this researches used the image processing system and algorithm instead of the existing a primary hand-line up. and fiber input array and waveguide chip formed in line by automatic. Therefore, the developed and manufactured optical aligning system in this research fulfills the great role of support industry for major electronics manufacturers, telecommunications companies, universities, government agencies and other research institutions.

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Fourier-Plane Encryption System using Divided Images and a Joint Transform Correlator (분할 영상과 결합변환 상관기를 이용한 주파수 영역에서의 광 암호화 시스템 구현)

  • 최상규;신창목;서동환;김수중;배장근
    • Proceedings of the Optical Society of Korea Conference
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    • pp.58-59
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    • 2003
  • We propose the optical encryption system using two divided image to hide the original image and a joint transform correlator. The encryption procedure is performed by the Fourier transform of the product of each phase encoded image (divided phase images) and the same random phase image which is generated by computer processing. An autocorrelation term of joint transform correlator contributes to decrypt the original image. This system will be used in optical certification.

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Aero-optical transmitting effect in the compressible mixing layer

  • Ma, Handong;Gan, Caijun;Li, Lang
    • International Journal of Aerospace System Engineering
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    • v.2 no.2
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    • pp.79-82
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    • 2015
  • The handicap for investigating the aero-optical effect focuses on the accurate prediction on the index refraction fluctuation or density fluctuation. In recent years, with the development of CFD techniques and optical experimental techniques, the comprehension have developed on the aero-optical transmitting effect in many kinds of complex flow. This study mainly introduces the optical aberration in compressible mixing layer. And then the debates about the mechanism of aero-optical effects and assessment of image blur also present.

Optical encryption system using phase-encoded virtual image (가상 위상 영상을 이용한 광학적 암호화 시스템)

  • 서동환;신창목;김수중;배장근;김철수;도양회
    • Korean Journal of Optics and Photonics
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    • v.14 no.3
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    • pp.249-254
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    • 2003
  • In this paper, we propose an improved image encryption and decryption method using a phase-encoded virtual image and interference. An original image is simply decrypted by interfering a reference wave with the wave passing through a decrypting key and the encrypted image, where every image has grey level. The proposed encryption is performed by the multiplication of an encrypting key and a phase-encoded virtual image which dose not contain any information for the original image. Therefore even if unauthorized people analyze the encrypted image, they cannot reconstruct the original image. Also grey image encryption can improve the encryption level compared to binary image encryption. Computer simulation and optical experiments confirmed that the proposed technique is a simple for optical encryption.