• Journal of International Society for Simulation Surgery
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• v.3 no.2
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• pp.39-45
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• 2016

The augmented reality is the environment which consists of real-world view and information drawn by computer. Since the image which user can see through augmented reality device is a synthetic image composed by real-view and virtual image, it is important to make the virtual image generated by computer well harmonized with real-view image. In this paper, we present reviews of several works about computer vision and graphics methods which give user realistic augmented reality experience. To generate visually harmonized synthetic image which consists of a real and a virtual image, 3D geometry and environmental information such as lighting or material surface reflectivity should be known by the computer. There are lots of computer vision methods which aim to estimate those. We introduce some of the approaches related to acquiring geometric information, lighting environment and material surface properties using monocular or multi-view images. We expect that this paper gives reader's intuition of the computer vision methods for providing a realistic augmented reality experience.

• ETRI Journal
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• v.27 no.6
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• pp.708-712
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• 2005

We propose a computational reconstruction technique in large-depth integral imaging where the elemental images have information of three-dimensional objects through real and virtual image fields. In the proposed technique, we reconstruct full volume information from the elemental images through both real and virtual image fields. Here, we use uniform mappings of elemental images with the size of the lenslet regardless of the distance between the lenslet array and reconstruction image plane. To show the feasibility of the proposed reconstruction technique, we perform preliminary experiments and present experimental results.

• Korean Journal of Optics and Photonics
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• v.18 no.2
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• pp.117-121
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• 2007

A fundamental problem in the in-line digital holography microscope is that the real image and virtual image and zero-order image are not separated spatially. In this paper, we have eliminated the zero-order noise by an averaging method and the twin image is divided using a geometrical set-up in an in-line digital holographic microscope. The size of the virtual image depends on the distance between the objective lens and the hologram plane and on the distance between the hologram plane and the image plane. We found that the virtual image size is smallest when the distance between the objective lens and the hologram plane is equal to the back focal length of the objective lens. We could divide the virtual image and real image by controlling the distance between the hologram plane and the objective lens.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.11
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• pp.83-90
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• 2004

In this paper we present a new real-time visual servoing unit for laparoscopic surgery This unit can automatically control laparoscope manipulator through visual tracking of laparoscopic surgical tool. For the tracking, we present two-stage adaptive CONDENSATION(conditional density propagation) algorithm to extract the accurate position of the surgical tool tip from a surgical image sequence in real-time. This algorithm can be adaptable to abrupt change of laparoscope illumination. For the control, we present virtual damper system to control a laparoscope manipulator safely and stably. This system causes the laparoscope to move under constraint of the virtual dampers which are linked to the four sides of image. The visual servoing unit operates the manipulator in real-time with locating the surgical tool in the center of image. The experimental results show that the proposed visual tracking algorithm is highly robust and the controlled manipulator can present stable view with safe.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.5
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• pp.409-419
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• 2013

Kinect released by Microsoft in November 2010 is a motion sensing camera in xbox360 and gives depth and color images. However, Kinect camera also generates holes and noise around object boundaries in the obtained images because it uses infrared pattern. Also, boundary flickering phenomenon occurs. Therefore, we propose a real-time virtual-view video synthesis algorithm which results in a high-quality virtual view by solving these problems. In the proposed algorithm, holes around the boundary are filled by using the joint bilateral filter. Color image is converted into intensity image and then flickering pixels are searched by analyzing the variation of intensity and depth images. Finally, boundary flickering phenomenon can be reduced by converting values of flickering pixels into the maximum pixel value of a previous depth image and virtual views are generated by applying 3D warping technique. Holes existing on regions that are not part of occlusion region are also filled with a center pixel value of the highest reliability block after the final block reliability is calculated by using a block based gradient searching algorithm with block reliability. The experimental results show that the proposed algorithm generated the virtual view image in real-time.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1996.06b
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• pp.83-87
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• 1996

A virtual reality system using video image is designed and implemented. A participant having 2{{{{ { 1} over { 2} }}}}DOF can interact with the computer-generated virtual object using her/his full body posture and gesture in the 3D virtual environment. The system extracts the necessary participant-related information by video-based sensing, and simulates the realistic interaction such as collision detection in the virtual environment. The resulting scene obtained by compositing video image of the participant and virtual environment is updated in near real time.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.11
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• pp.1317-1322
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• 2014

To complete an image, it is needed to go through the process to capture the actual actor's motion and compose it with virtual environment. Due to the excessive cost for production or lack of post-processing technology, however, it is mostly conducted by manual labor. The actor plays his role depending on his own imagination at the virtual chromakey studio, and at that time, he has to move considering the possible collision with or reaction to an object that does not exist. And in the process of composition applying CG, when the actor's motion does not go with the virtual environment, the original image may have to be discarded and it is necessary to remake the film. The current study suggested and realized depth-based real-time 3D virtual image composition system to reduce the ratio of remaking the film, shorten the production time, and lower the production cost. As it is possible to figure out the mutual collision or reaction by composing the virtual background, 3D model, and the actual actor in real time at the site of filming, the actor's wrong position or acting can be corrected right there instantly.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1430-1434
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• 2004

Recently, Virtual reality parts is applied in various fields of industry. In this paper we developed basic components for virtual robot control system interfaced with real environment. For this, a real robot with virtual interface module is developed and virtual robot of similar image with real robot is created by putting on 3D graphic texture to the real robot. To build an unknown environment to be linked with virtual environment, we proposed a hough transformation based algorithm. Our proposed algorithm consists of navigation module by using fuzzy engine and map building module. Experiments using a developed robot illustrate the method.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.3
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• pp.505-516
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• 2008

Image which appears in fashion illustration on the late twentieth century is not the representative image as an equivalence to the real fashion styles but the virtual image which bears no relation to any reality. The purpose of this study is review the concept of virtuality and analyze in which way virtual image is expressed in fashion illustrations on the background of Jean Baudrillard's simulacre theory. In post-modem paintings the expression methods of image-virtualization were image mixing through photo-image appropriation, image overlapping, and the icons inserted unreasonably, the focus-out effect through scrubbing and the over-painting on the photograph. Image-virtualization in fashion illustration was expressed through image mixing and expression of image uncertainty. Image mixing was made by photo-image appropriation, image overlapping, connection of heterogeneous images and using interface image, and uncertain image was expressed through the expression of visual ambiguity and virtual movement.

• Journal of Fashion Business
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• v.15 no.3
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• pp.97-111
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• 2011

This study aims to apply 3D virtual fabric parameters - as obtained from previous research experiments - to 3D virtual clothing simulation in comparing its similarity with actual clothing as worn, with a view to verifying the objectivity and validity of the 3D virtual fabric simulation method devised by the drape image analysis method. In addition, the result is intended to be used as the basic data for new 3D virtual clothing simulation methods. As the results, 3D virtual fabric parameters designed to simulate 3D drape to be similar to actual fabrics were found to be Bending Strength, Buckling Point, Density, Particle Distance, and Shear. They were also found to be important measurements when evaluating visual similarity between drape shadow images and number of nodes. 3D virtual fabric simulation method devised by the drape image analysis method was appropriate in extracting 3D fabric parameters with the reflection of actual fabrics' physical and dynamic characteristics, in connection with 3D virtual fabric simulation. 3D virtual fabric parameters with the reflection of actual fabrics' physical and dynamic characteristics using the proposed 3D virtual fabric simulation method are accumulated and provided as a standard, this will facilitate the introduction 3D virtual fabric simulation technology.