• Journal of the Optical Society of Korea
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• v.17 no.5
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• pp.405-409
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• 2013

In this paper, a unifying framework to evaluate the depth resolution of axially distributed image sensing (ADS) systems under fixed resource constraints is proposed. The proposed framework enables one to evaluate the system performance as a function of system parameters such as the number of cameras, the number of pixels, pixel size, and so on. The Monte Carlo simulations are carried out to evaluate ADS system performance as a function of system parameters. To the best of our knowledge, this is the first report on quantitative analysis of ADS systems under fixed resource constraints.

• Journal of information and communication convergence engineering
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• v.13 no.4
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• pp.270-274
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• 2015

In this paper, we propose an improved framework to analyze an N-ocular imaging system under fixed constrained resources such as the number of image sensors, the pixel size of image sensors, the distance between adjacent image sensors, the focal length of image sensors, and field of view of image sensors. This proposed framework takes into consideration, for the first time, the defocusing effect of the imaging lenses according to the object distance. Based on the proposed framework, the N-ocular imaging system such as integral imaging is analyzed in terms of depth resolution using two-point-source resolution analysis. By taking into consideration the defocusing effect of the imaging lenses using ray projection model, it is shown that an improved depth resolution can be obtained near the central depth plane as the number of cameras increases. To validate the proposed framework, Monte Carlo simulations are carried out and the results are analyzed.

• Journal of the Korean Applied Science and Technology
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• v.15 no.3
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• pp.33-37
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• 1998

The hardening test of gelatin with 2,4-dichloro-6-hydroxy-1,3,5-triazine mono sodium salt was studied at pH 5, 7, 8 and about increasing temperature, respectively. The hardener was prepared by the reaction of cyanuric chloride with sodium hydroxide, disodium hydrogenphosphate-12-water and trisodium phosphate-12-water in the presence of water. The product was identified by elemental analyzer. IR spectrophotometer. Novel hardener can be used in photographic emulsion and showed very good hardening effect.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1135-1137
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• 2008

In this paper, it is proposed that the integral imaging technique is applied to reconstruct 3D (three dimensional) objects with enhanced depth of field, computationally and optically. Lens array using birefringence material is adopted to obtain the reconstruction. The elemental images sets are picked up through common micro lens array and utilized to present 3D reconstruction images using adopted lens array.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1588-1591
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• 2005

In this paper, we propose novel computational reconstruction technique of three-dimensional objects in integral imaging by use of a lenslet array. We applied our technique to two different integral imaging systems according the distance between lenslet array and elemental image plane. Experimental results are presented and discussed as well.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.238-239
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• 2003

집적결상(integral imaging)에서 렌즈어레이(lens array)를 이용하여 3차원적인 물체를 기본영상(elemental image)들로 결상한 후, 다시 그 기본 이미지들로부터 3차원 이미지를 재생하는 과정에서 기본 이미지들을 변환시키지 않으면, 3차원 이미지가 재생될 때, 렌즈어레이와 수직한 축에 대해 렌즈어레이에 가까운 쪽과 먼 쪽이 서로 바뀌는 슈도스코픽(pseudoscopic) 현상이 일어난다. 그래서 기본이미지들을 변환시키기 위해 렌즈어레이를 한번 더 사용한 이단 집적결상계를 이용하거나 영상처리 방법을 이용하는데, 이와 같은 방법은 광학적 손실을 크게 하거나 처리 속도를 느리게 한다. (중략)

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1338-1340
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• 2009

High resolution three-dimensional integral imaging display is proposed. Each time-multiplexed image is projected with different incident angle on same array of elemental lenses. Those images are collected at different positions in focal plane of lens array, and thus the number of the point light sources increases and their spacing decreases. Therefore, proposed method can create high resolution 3D images.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.610-615
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• 2005

Visual servoing is the fusion of results from many elemental areas including high-speed image processing, kinematics, dynamics, control theory, and real-time computing. It has much in common with research into active vision and structure from motion, but is quite different from the often described use of vision in hierarchical task-level robot control systems. We present a new approach to visual feedback control using image-based visual servoing with the stereo vision in this paper. In order to control the position and orientation of a robot with respect to an object, a new technique is proposed using a binocular stereo vision. The stereo vision enables us to calculate an exact image Jacobian not only at around a desired location but also at the other locations. The suggested technique can guide a robot manipulator to the desired location without giving such priori knowledge as the relative distance to the desired location or the model of an object even if the initial positioning error is large. This paper describes a model of stereo vision and how to generate feedback commands. The performance of the proposed visual servoing system is illustrated by the simulation and experimental results and compared with the case of conventional method for dual-arm robot made in Samsung Electronics Co., Ltd.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.369-375
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• 2009

In this paper, we propose a 2D-3D convertible display system having a background of full-parallax integral images. The proposed system is composed of integral imaging system and conventional 2D flat display and is able to operate either 3D mode or 2D mode. In 3D mode, the 3D image is generated by combining the 2D main image with the background image based on integral imaging. In 2D mode, the integral imaging system plays a role as the back-light of 2D flat display and then 2D image is observed through 2D flat display. To show the usefulness of the proposed system, we carry out the preliminary experiments and present the successful experimental results.

• Journal of information and communication convergence engineering
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• v.16 no.3
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• pp.153-159
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• 2018

In this paper, we present a three-dimensional (3D) optical encryption technique for quick response (QR) code using computational synthesized integral imaging, computational volumetric reconstruction, and double random phase encryption. Two-dimensional (2D) QR code has many advantages, such as enormous storage capacity and high reading speed. However, it does not protect primary information. Therefore, we present 3D optical encryption of QR code using double random phase encryption (DRPE) and an integral imaging technique for security enhancement. We divide 2D QR code into four parts with different depths. Then, 2D elemental images for each part of 2D QR code are generated by computer synthesized integral imaging. Generated 2D elemental images are encrypted using DRPE, and our method increases the level of security. To validate our method, we report simulations of 3D optical encryption of QR code. In addition, we calculated the peak side-lobe ratio (PSR) for performance evaluation.