Transactions of the Virtual Reality Society of Japan
Online ISSN : 2423-9593
Print ISSN : 1344-011X
ISSN-L : 1344-011X
Volume 17 , Issue 3
Showing 1-24 articles out of 24 articles from the selected issue
  • Type: Cover
    2012 Volume 17 Issue 3 Pages Cover1-
    Published: September 30, 2012
    Released: February 01, 2017
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  • Type: Index
    2012 Volume 17 Issue 3 Pages Toc1-
    Published: September 30, 2012
    Released: February 01, 2017
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  • Type: Index
    2012 Volume 17 Issue 3 Pages Toc2-
    Published: September 30, 2012
    Released: February 01, 2017
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  • Itaru Kitahara, Masayuki Kanbara
    Type: Article
    2012 Volume 17 Issue 3 Pages 137-
    Published: September 30, 2012
    Released: February 01, 2017
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  • Type: Appendix
    2012 Volume 17 Issue 3 Pages 138-
    Published: September 30, 2012
    Released: February 01, 2017
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  • Fumio Okura, Masayuki Kanbara, Naokazu Yokoya
    Type: Article
    2012 Volume 17 Issue 3 Pages 139-149
    Published: September 30, 2012
    Released: February 01, 2017
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    This paper describes a method for acquiring full spherical videos without missing areas using a pair of omnidirectional cameras mounted on the top and bottom of an unmanned airship. Omnidirectional videos are captured as multi-exposure images with various shutter speeds to realize high dynamic range (HDR) imaging. The generated videos are intended to be used for telepresence, augmented telepresence, and image-based lighting. In experiments, full spherical HDR videos are generated from image sequences captured from the sky of our campus.
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  • Norihisa Hashimoto, Yoshitsugu Yanagi, Yoshiharu Deguchi
    Type: Article
    2012 Volume 17 Issue 3 Pages 151-160
    Published: September 30, 2012
    Released: February 01, 2017
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    The development of a small spherical display with rotary LED arrays called "Panorama Ball Vision" is described. An omnidirectional image shooting system mating to the display is also mentioned. The display was planned to realize the moving-image version of Hashimoto's "Panorama Ball" which is novel way of expressing space by pasting the surrounding field of view onto the outside surface of a sphere. Besides panoramic images, the display can show other kind of spherical images like the moon, the globe, and the celestial globe.
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  • Daiki Matsuda, Keiji Uemura, Nobuchika Sakata, Shogo Nishida
    Type: Article
    2012 Volume 17 Issue 3 Pages 161-169
    Published: September 30, 2012
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    Due to the prevalence of cell phones many people view information on small handheld LCD screens. However, these mobile devices require the use of one hand, the user needs to keep a close watch on a small display, and they have to be retrieved from a pocket or a bag. To overcome these problems, we focus on wearable projection systems that enable hands-free viewing via large projected screens, eliminating the need to retrieve and hold devices. In this paper, we present a toe input system that can realize haptic interaction, direct manipulation, and floor projection using a wearable projection system with a large projection surface. It is composed of a mobile projector, Kinect depth camera, and a gyro sensor. It is attached to the user's chest and can detect when the users foot touches or rises from the floor. To evaluate the system we conducted experiments investigating object selection and screen scroll by foot motion.
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  • Keiji Uemura, Nobuchika Sakata, Shogo Nishida
    Type: Article
    2012 Volume 17 Issue 3 Pages 171-179
    Published: September 30, 2012
    Released: February 01, 2017
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    This research focuses on the remote collaboration in which a local worker works with real objects by a remote instructor. The goal of this research is to achieve an interaction which allows a remote instructor to provide a local worker with clear and accurate instruction. In particular, the ProCam system consisting of a camera and a projector is placed at the work environment, and the tabletop system consisting of a display, a depth sensor and a camera is placed at remote instructor environment. In remote instructor environment, the image captured by the ProCam system on the work environment is displayed on the tabletop display at the remote location. Next, the instructor's arm is extracted from the image of the instruction environment by the depth sensor. Then, overlapping the image to the work environment allows communicating with keeping information of the embodiment which consists of the moving arms and the pointing. That system is called a view sharing system. The conventional view sharing systems have a problem that is difficult for an instructor to provide detail direction in the remote collaboration. To solve this problem, we propose to use scalable embodiment image as instruction image. Lastly, we conducted the user study to examine the effectivity of the proposal method.
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  • Toshihiro Honda, Hideo Saito
    Type: Article
    2012 Volume 17 Issue 3 Pages 181-190
    Published: September 30, 2012
    Released: February 01, 2017
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    In this paper, we present a system for real-time Diminished Reality using multiple smartphones. In this system, we assume multiple smartphones capture the same scene that is occluded by obstacles. Areas of the obstacles are extracted from each camera image replaced with image of the hidden areas which are captured using different viewpoint camera. In the proposed method, we suppose that the target scene can be approximated as a plane. Therefore, we compute Homography between each camera image by using natural features. Then, obstacle area which is not approximated as a plane can be removed by synthesizing the image warped with the Homography and the user viewpoint image. We can perform real-time processing because we send each camera image to PC which returns obstacle-removed images at every frame. We experimentally demonstrate the effectiveness of the proposed method using three viewpoint images.
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  • Takumi Yoshida, Hideo Saito, Masayoshi Shimizu, Akinori Taguchi
    Type: Article
    2012 Volume 17 Issue 3 Pages 191-200
    Published: September 30, 2012
    Released: February 01, 2017
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    We propose a planar pose estimation method that is robust to viewpoint changes. Conventional local features such as SIFT, SURF, etc., have scale and rotation invariance but often fail in keypoint matching when the camera pose significantly changes. To solve this problem we adopt viewpoint generative learning. By generating various patterns as seen from different viewpoints and collecting local features, our system can learn a set of descriptors under various camera poses for each keypoints before actual matching. Experimental results comparing usual local feature matching or patch classification method show both robustness and fastness of learning. Proposed method can achieve a markerless AR system that sets a tracking target on site.
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  • Keisuke Hirose, Hideo Saito
    Type: Article
    2012 Volume 17 Issue 3 Pages 201-208
    Published: September 30, 2012
    Released: February 01, 2017
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    Simultaneous localization and mapping (SLAM) is a technique to simultaneously performs mapping of environments and localization of a camera in real-time. Most existing monocular vision based SLAM techniques use point features as landmarks. However, the use of line segments as landmarks has some advantages. We propose a novel method for a real-time SLAM system that uses line segments as landmarks and computes a Line-based Eight-directional Histogram Feature (LEHF), which is our new line descriptor, to achieve correct matching. LEHF is a fast and efficient way of describing features of line segments, which are detected by the line segment detector (LSD) method. The line-based orthogonal iteration (LBOI) method takes the confidence of each 3D line segment into consideration in order to estimate a camera pose from 2D-3D correspondences made by line descriptor matching. The RANSAC algorithm is applied for 2D-3D correspondences to estimate the correct camera pose. We conducted an experiment in order to test our SLAM system in a desktop environment and to perform augmented reality (AR). Mapped 3D line segments were also evaluated in a planar scene.
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  • Hozuma Nakajima, Ikuhisa Mitsugami, Hirotake Yamazoe, Hitoshi Habe, Ya ...
    Type: Article
    2012 Volume 17 Issue 3 Pages 209-217
    Published: September 30, 2012
    Released: February 01, 2017
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    Existing background subtraction methods often fail to extract a foreground region whose color is similar to that of the background. When we use a co-located camera and range sensor, by which we can obtain both a color image and depth map simultaneously, it is expected to get a better foreground region by integrating the two kind of images. However, it is not straightforward when a moving object is observed because the camera and range sensor do not capture the scene synchronously. In this paper, we propose a novel method that pseudo-synchronize the camera and range sensor and integrate the background subtraction of the color and depth images to realize a good foreground extraction. Experimental results of a walking human show its effectiveness.
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  • Yoshihiro Watanabe, Tetsuo Hatanaka, Takashi Komuro, Masatoshi Ishikaw ...
    Type: Article
    2012 Volume 17 Issue 3 Pages 219-229
    Published: September 30, 2012
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    We focus on the growing need for a technology that can achieve motion capture in outdoor environments. The conventional approaches have relied mainly on fixed installed cameras. With this approach, however, it is difficult to capture motion in everyday surroundings. This paper describes a new method for motion estimation using a single wearable camera. We focused on walking motion. The key point is how the system can estimate the original walking state using limited information from a wearable sensor. This paper describes three aspects: the configuration of the sensing system, gait representation, and the gait estimation method.
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  • Shohei Mori, Ryosuke Ichikari, Fumihisa Shibata, Asako Kimura, Hideyuk ...
    Type: Article
    2012 Volume 17 Issue 3 Pages 231-240
    Published: September 30, 2012
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    This paper proposes a pre-visualization (PreViz) system for stereoscopic 3D (S3D) filmmaking using mixed reality (MR) technologies. This system superimposes CG characters on real background shot in S3D with cinematographic stereo-camera. In preproduction stages, this enables stereographers to examine stereo-camera settings on-site by trial and error. Proposed system is based on our previous work, MR-PreViz, which provides MR composited PreViz and was designed as S3D extended of it. The S3D extension includes not only system design and development but also camera tracking method using a stereo-camera. Contribution of this method is to use epipolar constraints of the stereo-camera for structure-from-motion based approach and, as a result, is to increase variations of camera-paths examined in our PreViz system. We confirmed that the variations increased by visualizing camera-paths and by MR-PreViz movies, and we also evaluated the method in quantitative manners.
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  • Ryosuke Ichikari, Takahiro Nagakari, Yuuki Tsumura, Kazuhiro Kitamura, ...
    Type: Article
    2012 Volume 17 Issue 3 Pages 241-252
    Published: September 30, 2012
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    This paper describes a high-performance camera tracking method for filmmaking under the certain restriction on the camera path. The proposed method called "rehearsal path method" realizes real-time geometric registration using a landmark database which was constructed in advance. Furthermore, the rehearsal path method has three efforts against two actual problems of marker-less tracking methods: (1) the case of wide scene, and (2) the case of scene which has unstable feature points such as trees. Finally, some experimental results were shown in order to confirm and discuss convenience of use and performance improvement.
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  • Yurina Takata, Piao Wanning, Masami Hachiya, Kentaro Takata, Shiho Nis ...
    Type: Article
    2012 Volume 17 Issue 3 Pages 253-260
    Published: September 30, 2012
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    In this study, we propose a method of digital archive of information about the marine ecosystem. Information about the marine ecosystem is a multi-dimensional information, including the time axis. However, the appropriate means to do a digital archive so you can view these to overview holistic information did not exist. Therefore, by using appropriate VR technology, we intend to establish the content to be extended allowing a cross-reference of pluralistic information about the ocean, and a participation for user in the construction of a digital archive. As an example implementation of the present study, we cite "Yoron Diver", digital archive content of marine information in Yoron Island. In order to achieve the purpose of this study, it is valid to be displayed overlaid on the digital globe with data submitted by users, three-dimensional terrain models of the seabed, and photographs undersea. If this approach is used, this is possible to prompt a deeper understanding for users.
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  • Saeko Shimazu, Daisuke Iwai, Kosuke Sato
    Type: Article
    2012 Volume 17 Issue 3 Pages 261-268
    Published: September 30, 2012
    Released: February 01, 2017
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    This paper presents a method to compute the optimal placement of multiple projectors in projection-based mixed reality (MR). We aim to find the optimal placement that maximizes spatial resolution of projected images while minimizing shadow areas on a projection surface. To achieve this, we propose to evaluate the projected pixel density and find a projector placement in which the density is the closest to a target density value. The pixel density is computed by the geometric relationship among the projectors and the surface. Once the density is calculated, the proposed method finds the optimal placement based on Generic Algorithm. We show results of computed optimal projector placement. At last, projection results are shown in which projectors are placed at the optimal position.
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  • Takanori Ueda, Shunsuke Shishido, Rei Takahashi, Minoru Ito
    Type: Article
    2012 Volume 17 Issue 3 Pages 269-278
    Published: September 30, 2012
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    This paper presents a locomotion interface system using a type of the treadmill called Ball array treadmill (BAT), which consists of a walking board, a belt conveyer and a turntable. Balls on the board rotate with the belt conveyer and the turntable changes belt conveyer direction. The two-dimensional sensor array is embedded under the walking board to detect the walker position. When a person walks in 2D direction on the board, sensors under the board detect the walker foot positions and the ball rotation draws him back to the center of the board. The system with the PID control of foot positions was constructed and it was made clear that a walker on the board remains within the board area while it walks on the board two-dimensionally. This walk cancellation realizes an infinite 2D walk-through environment in virtual worlds. The mechanical structure of this device is simple and suits the practical use well.
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  • Tomoko Hashida, Yasuaki Kakehi, Takeshi Naemura
    Type: Article
    2012 Volume 17 Issue 3 Pages 279-288
    Published: September 30, 2012
    Released: February 01, 2017
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    SolaColor is a scheme for creating a place whose color is varied in response to sunlight. The aim of this work is to create sustainable spatial rendition by utilizing sunlight. A feature of this spatial-rendition scheme is rendering places by color-rather than contrast-of lighting. By means of SolaColor, areas in sunlight are colored, while shaded areas are coloress. When this scheme is practically applied, time-varying patterns appear in synchronization with the movement of the sun. When a person or object enters a space created by SolaColor, white shadows oriented according to the position of the sun are formed in the manner of a sundial. The scheme can be implemented by utilizing photochromic material and optical design, and it can be introduced in any location under sunlight without the need for an electrical-power supply.
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  • Junghyun Kim, Tomoko Hashida, Tomoko Ohtani, Takeshi Naemura
    Type: Article
    2012 Volume 17 Issue 3 Pages 289-292
    Published: September 30, 2012
    Released: February 01, 2017
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    In this paper, we explain quantitatively how the auditory feedback of writing sound between ordinary pen and paper influences the efficiency of simple writing tasks. Specifically, we evaluated the speeds in the simple task of tracing Chinese characters without auditory feedback, with natural writing sound, and with emphasized writing sound. The results of this study showed that users traced more characters and also had positive impressions with emphasized writing sound feedback in contrast with the other two conditions.
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  • Type: Appendix
    2012 Volume 17 Issue 3 Pages 293-295
    Published: September 30, 2012
    Released: February 01, 2017
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  • Type: Appendix
    2012 Volume 17 Issue 3 Pages App1-
    Published: September 30, 2012
    Released: February 01, 2017
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  • Type: Cover
    2012 Volume 17 Issue 3 Pages Cover2-
    Published: September 30, 2012
    Released: February 01, 2017
    JOURNALS FREE ACCESS
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