• 한국지구물리탐사학회:학술대회논문집
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• 2000.09a
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• pp.41-53
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• 2000

Electrical resistivity survey is widely applied to the dam seepage problems. Main purpose of the resistivity survey is to delineate the inhomogeneity in the dam. In this study, two- (2-D) and three-dimensional (3-D) resistivity survey methodology and corresponding interpretations of the data have been analyzed using 3-D resistivity modeling results. Since resistivity structures beneath the dam and its shape are 3-D in nature, we could get more accurate image of the dam structures using 3-D survey compared to 2-D survey even though we cannot employ the grid-shape survey layout.

• Journal of the Optical Society of Korea
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• v.17 no.5
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• pp.410-414
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• 2013

In this paper, we propose a 3D display method combining a pickup process using axially recorded multiple images and an integral imaging display process. First, we extract the color and depth information of 3D objects for displaying 3D images from axially recorded multiple 2D images. Next, using the extracted depth map and color images, elemental images are computationally synthesized based on a ray mapping model between 3D space and an elemental image plane. Finally, we display 3D images optically by an integral imaging system with a lenslet array. To show the usefulness of the proposed system, we carry out optical experiments for 3D objects and present the experimental results.

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.142-143
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• 2002

KIST에서는 Pulsed Laser를 사용하여 3차원 image를 재생할 수 있는 Electro-Holographic System을 만들어 CGH이미지를 구현하였다. CGH 이미지를 구현하기 위한 SLM (Spatial Light Modulator)으로 TeO$_2$ 결정의 Shear Mode 에서 동작하는 Bragg type의 다채널 AOSLM(Acousto-optic Spatial Light Modulator)이 사용되었다. 이 Bragg type 다채널 AOSLM에서는 광원이 특정 Bragg 각도로 입사하였을 때 다른 고위 차수는 억압되고 ＋나 -의 첫번째 차수의 회절 빔만이 형성된다. (중략)

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.167-174
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• 2016

In this paper, we propose a generation of 2D elemental images for 3D objects using Kinect in 3D depth-priority integral imaging (DPII) display. First, we analyze a principle to pickup elemental images based on ray optics. Based on our analysis, elemental images are generated with both RGB image and depth image recorded from Kinect. We reconstruct 3D images from the elemental images with the computational integral imaging reconstruction technique and then compare various perspective images. To show the usefulness of the proposed method, we carried out the preliminary experiments. The experimental results reveal that our method can provide correct 3D images with full parallax.

• Journal of the Optical Society of Korea
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• v.17 no.2
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• pp.162-167
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• 2013

A two-dimensional (2D) / three-dimensional (3D) convertible display system based on integral imaging is proposed to adopt a novel switchable point light source array, which is implemented using the polarization modulator and the polarization selective scattering film that transmits or scatters the incident light due to its polarization direction. The 2D and the 3D display modes of the proposed system can be modulated by controlling the polarization direction of back light using the polarization modulator. We explain the basic principles of the proposed system and verify the feasibility of the system through preliminary experiments.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.158-163
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• 2009

In recent years, there has been increased interest in characterizing and extracting 3D information from 2D images for human tracking and identification. In this paper, we propose a single view-based framework for robust estimation of height and position. In the proposed method, 2D features of target object is back-projected into the 3D scene space where its coordinate system is given by a rectangular marker. Then the position and the height are estimated in the 3D space. In addition, geometric error caused by inaccurate projective mapping is corrected by using geometric constraints provided by the marker. The accuracy and the robustness of our technique are verified on the experimental results of several real video sequences from outdoor environments.

• 한국지구물리탐사학회:학술대회논문집
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• 2000.09a
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• pp.147-157
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• 2000

Primary purpose of the system developed in this study is 3-D seismic data processing system for underground investigation and this system is developed in PC based on Linux for lower-cost system. Basic data processing modules are originated from SU (Seismic Unix) which is widely used in 2-D seismic data processing and auxilious modules are developed for 3-D data processing The system which is constructed by using these data processing modules Is designed to GUI (Graphic User Interface) in order that one can easily control and for this purpose, GTK (Gimp Tool KiT) conventionally adapted in producing Linux application.

• Journal of the Optical Society of Korea
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• v.19 no.6
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• pp.629-637
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• 2015

Compact system cameras (CSCs) are commonly used nowadays and feature enhanced video functions and thin yet light interchangeable lenses. They differ from digital single-lens reflex (DSLR) cameras in their lack of mirror boxes. CSCs, however, have autofocus (AF) speeds lower than those of conventional DSLRs, requiring weight reduction of their AF groups. To ensure the marketability of large telephoto zoom lenses with fixed f/2.8 regardless of field angle variation, in particular, light weight AF groups are essential. In this paper, we introduce a paraxial optical design method and present a new, large, telephoto zoom lens with f/2.8 regardless of the field angle variation, plus a lightweight AF group consisting of only one lens. Using the basic paraxial optical design and optimization methods, we fabricated a new and lighter zoom lens system, including a single-lens, lightweight AF group with almost the same performance.

• The Journal of Korea Robotics Society
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• v.11 no.2
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• pp.51-59
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• 2016

In this paper we present (1) analysis of imaging sonar measurement for two-view relative pose estimation of an autonomous vehicle and (2) bundle adjustment and 3D reconstruction method using imaging sonar. Sonar has been a popular sensor for underwater application due to its robustness to water turbidity and visibility in water medium. While vision based motion estimation has been applied to many ground vehicles for motion estimation and 3D reconstruction, imaging sonar addresses challenges in relative sensor frame motion. We focus on the fact that the sonar measurement inherently poses ambiguity in its measurement. This paper illustrates the source of the ambiguity in sonar measurements and summarizes assumptions for sonar based robot navigation. For validation, we synthetically generated underwater seafloor with varying complexity to analyze the error in the motion estimation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.5
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• pp.1207-1212
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• 2015

In this paper, we propose three-dimensional (3D) visualization and recognition techniques of micro-objects under photon-starved conditions using photon counting integral imaging microscopy. To capture high resolution 2D images with different perspectives in the proposed method, we use Synthetic Aperture Integral Imaging (SAII). Poisson distribution which is mathematical model of photon counting imaging system is used to extract photons from the images. To estimate 3D images with 2D photon counting images, the statistical estimation is used. Therefore, 3D images can be obtained and visualized without any damage under photon-starved conditions. In addition, 3D object recognition can be implemented using nonlinear correlation filters. To prove the usefulness of our technique, we implemented the optical experiment.