• Title/Summary/Keyword: motion stereo

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Stereoscopic Video Coding for Subway Accident Monitoring System (지하철 사고 감시를 위한 스테레오 비디오 부호화 기법)

  • Oh, Seh-Chan;Kim, Gil-Dong;Park, Sung-Hyuk
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.484-486
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    • 2005
  • Passenger safety is a primary concern of railway system but, it has been urgent issue that dozens of people are killed every year when they falloff from train platforms. Recently, advancements in IT have enabled applying vision sensors to railway environments, such as CCTV and stereo camera sensors. In this paper, we propose a stereoscopic video coding scheme for subway accident monitoring system. The proposed scheme is designed for providing flexible video among various displays, such as control center, station employees and train driver. We uses MPEG-2 standard for coding the left-view sequence and IBMDC for predicting the P- and B-types of frames of the right-view sequence. IBMDC predicts matching block by interpolating both motion and disparity predicted macroblocks. To provide efficient stereoscopic video service. we define both temporally and spatially scalable layers for each eye's-view by using the concept of Spatio-Temporal scalability. According to the experimental results. we expect the proposed functionalities will play a key role in establishing highly flexible stereoscopic video codec for ubiquitous display environment where devices and network connections are heterogeneous.

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Post-earthquake building safety evaluation using consumer-grade surveillance cameras

  • Hsu, Ting Y.;Pham, Quang V.;Chao, Wei C.;Yang, Yuan S.
    • Smart Structures and Systems
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    • v.25 no.5
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    • pp.531-541
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    • 2020
  • This paper demonstrates the possibility of evaluating the safety of a building right after an earthquake using consumer-grade surveillance cameras installed in the building. Two cameras are used in each story to extract the time history of interstory drift during the earthquake based on camera calibration, stereo triangulation, and image template matching techniques. The interstory drift of several markers on the rigid floor are used to estimate the motion of the geometric center using the least square approach, then the horizontal interstory drift of any location on the floor can be estimated. A shaking table collapse test of a steel building was conducted to verify the proposed approach. The results indicate that the accuracy of the interstory drift measured by the cameras is high enough to estimate the damage state of the building based on the fragility curve of the interstory drift ratio. On the other hand, the interstory drift measured by an accelerometer tends to underestimate the damage state when residual interstory drift occurs because the low frequency content of the displacement signal is eliminated when high-pass filtering is employed for baseline correction.

Terrain surveying for gully in Svalbard using UAV and comparison with Mars (UAV를 이용한 스발바르 걸리 지형의 측량과 화성 걸리와의 비교)

  • LEE, Jaeyong;OGUCHI, Takashi
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.1
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    • pp.72.4-73
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    • 2018
  • 북극 스발바르의 사면 지형에는 걸리가 발달되어 있다. 이러한 걸리는, 그 성인에는 여러 의견이 있으나, 화성에도 중고위도를 중심으로 다수 분포한다. 화성의 걸리는 2000년대에 들어 비로소 본격적으로 규명되고 있으나, 지형적 특성으로 인한 탐사의 한계로 지구에 분포하는 유사지형을 통한 비교 연구가 일반적이다(Costard, et al. 2007 등). 이 연구에서는 스발바르의 주도 롱이어비엔에서 UAV을 이용하여 획득한 DEM으로 스발바르 걸리를 측량하고, 이를 화성 중위도의 테라 사이메리아, 테라 시레넘, 노아 키스 테라에 분포하는 걸리와 비교하였다. Longyearbreen 빙하 전방에 위치한 사면을 UAV로 촬영하고, 이를 SfM-MVS(Structure from Motion & MultiView Stereo) 기법으로 3차원 점군 모델과 고해상도 DEM을 제작하여 분석하였다. 화성의 경우 MRO궤도 탐사선이 촬영한 HiRise DTM을 이용하여 분석하였다. 두 걸리는 기후와 지질 조건에 차이가 있음에도 불구하고 유사한 패턴을 보였다. 특히 테라 사이메리아에 위치한 걸리와 롱이어비엔 북사면의 걸리는 기준거리, 단면적, 폭, 경사, 제방 두께 등에서 상당한 정량적 유사관계가 있었다. 이는 두 행성의 걸리가 유사한 성인 및 형성 프로세스를 거쳤을 가능성을 시사한다. 측량 기법과 UAV 의 안정성을 개선시키면 지형 모델의 품질 향상 및 극지에서의 UAV 운용이 용이해질 것으로 기대된다. 또한 스발바르의 기후 요소 및 물리량 적용은 향후 화성 지형연구에도 응용할 수 있을 것으로 사료된다.

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Visual Touchless User Interface for Window Manipulation (윈도우 제어를 위한 시각적 비접촉 사용자 인터페이스)

  • Kim, Jin-Woo;Jung, Kyung-Boo;Jeong, Seung-Do;Choi, Byung-Uk
    • Journal of KIISE:Software and Applications
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    • v.36 no.6
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    • pp.471-478
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    • 2009
  • Recently, researches for user interface are remarkably processed due to the explosive growth of 3-dimensional contents and applications, and the spread class of computer user. This paper proposes a novel method to manipulate windows efficiently using only the intuitive motion of hand. Previous methods have some drawbacks such as burden of expensive device, high complexity of gesture recognition, assistance of additional information using marker, and so on. To improve the defects, we propose a novel visual touchless interface. First, we detect hand region using hue channel in HSV color space to control window using hand. The distance transform method is applied to detect centroid of hand and curvature of hand contour is used to determine position of fingertips. Finally, by using the hand motion information, we recognize hand gesture as one of predefined seven motions. Recognized hand gesture is to be a command to control window. In the proposed method, user can manipulate windows with sense of depth in the real environment because the method adopts stereo camera. Intuitive manipulation is also available because the proposed method supports visual touch for the virtual object, which user want to manipulate, only using simple motions of hand. Finally, the efficiency of the proposed method is verified via an application based on our proposed interface.

Articulated Human Body Tracking Using Belief Propagation with Disparity Map (신뢰 전파와 디스패리티 맵을 사용한 다관절체 사람 추적)

  • Yoon, Kwang-Jin;Kim, Tae-Yong
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.49 no.3
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    • pp.51-59
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    • 2012
  • This paper suggests an efficient method which tracks articulated human body modeled with markov network using disparity map derived from stereo images. The conventional methods which only use color information to calculate likelihood for energy function tend to fail when background has same colors with objects or appearances of object are changed during the movement. In this paper, we present a method evaluating likelihood with both disparity information and color information to find human body parts. Since the human body part are cylinder projected to rectangles in 2D image plane, we use the properties of distribution of disparity of those rectangles that do not have discontinuous distribution. In addition to that we suggest a conditional-messages-update that is able to reduce unnecessary message update of belief propagation. Since the message update has comprised over 80% of the whole computation in belief propagation, the conditional-message-update yields 9~45% of improvements of computational time. Furthermore, we also propose an another speed up method called three dimensional dynamic models assumed the body motion is continuous. The experiment results show that the proposed method reduces the computational time as well as it increases tracking accuracy.

Developing a Sensory Ride Film 'Dragon Dungeon Racing' (효율적인 입체 라이드 콘텐츠 제작을 위한 연구)

  • Chae, Eel-Jin;Choi, Chul-Young;Choi, Kyu-Don;Kim, Ki-Hong
    • The Journal of the Korea Contents Association
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    • v.11 no.2
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    • pp.178-185
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    • 2011
  • The recent development of 3D and its application contents have made it possible for people to experience more various 3D contents such as 3D/4D, VR, 3D ride film, I-max, sensory 3D games at theme parks, large-scale exhibitions, 4D cinemas and Video ride. Among them, Video ride, a motion-based genre, especially is getting more popularity, where viewers are immersed in and get indirect experiences in virtual reality. In this study, the production process of the genre of sensory 3D image getting attention recently and ride film are introduced. In the material selection of 3D images, the space and the setting up which is suitable to the fierce movement of rides are studied and some examples of the realization of creative direction ideas and effective technologies using the functions of Stereo Camera which has been first applied to MAYA 2009 are also illustrated. When experts in this 3D image production create more interesting stories with the cultural diversity and introduce enhanced 3D production techniques for excellent contents, domestic relevant companies will be sufficiently able to compete with their foreign counterparts and further establish their successfully unique and strong domains in the image contents sector.

Depth map temporal consistency compensation using motion estimation (움직임 추정을 통한 깊이 지도의 시간적 일관성 보상 기법)

  • Hyun, Jeeho;Yoo, Jisang
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.2
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    • pp.438-446
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    • 2013
  • Generally, a camera isn't located at the center of display in a tele-presence system and it causes an incorrect eye contact between speakers which reduce the realistic feeling during the conversation. To solve this incorrect eye contact problem, we newly propose an intermediate view reconstruction algorithm using both a color camera and a depth camera and applying for the depth image based rendering (DIBR) algorithm. In the proposed algorithm, an efficient hole filling method using the arithmetic mean value of neighbor pixels and an efficient boundary noise removal method by expanding the edge region of depth image are included. We show that the generated eye-contacted image has good quality through experiments.

Vision-based Walking Guidance System Using Top-view Transform and Beam-ray Model (탑-뷰 변환과 빔-레이 모델을 이용한 영상기반 보행 안내 시스템)

  • Lin, Qing;Han, Young-Joon;Hahn, Hern-Soo
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.12
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    • pp.93-102
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    • 2011
  • This paper presents a walking guidance system for blind pedestrians in an outdoor environment using just one single camera. Unlike many existing travel-aid systems that rely on stereo-vision, the proposed system aims to get necessary information of the road environment by using just single camera fixed at the belly of the user. To achieve this goal, a top-view image of the road is used, on which obstacles are detected by first extracting local extreme points and then verified by the polar edge histogram. Meanwhile, user motion is estimated by using optical flow in an area close to the user. Based on these information extracted from image domain, an audio message generation scheme is proposed to deliver guidance instructions via synthetic voice to the blind user. Experiments with several sidewalk video-clips show that the proposed walking guidance system is able to provide useful guidance instructions under certain sidewalk environments.

A Study of Pedestrian Navigation Service System for Visual Disabilities (시각장애인용 길안내 서비스 시스템에 대한 연구)

  • Jang, Young Gun;Cha, J.H.
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.11 no.4
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    • pp.315-321
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    • 2017
  • This paper is a study on the design and realization of Pedestrian navigation service system for the visually impaired. As it is an user interface considering visually impaired, voice recognition functioned smartphone was used as the input tool and the Osteoacusis headset, which can vocally guide directions while recognizing the surrounding environment sound, was used as the output tool. Unlike the pre-existing pedestrian navigation smartphone apps, the developed system guides walking direction by the scale of the left and right stereo sound of the headset wearing, and the voice guidance about the forked or curved path is given several meters before according to the speed of the user, and the user is immediately warned of walking opposite direction or proceeding off the path. The system can acquire stable and reliable directional information using the motion tracker with the dynamic heading accuracy of 1.5 degrees. In order to overcome GPS position error, we proposed a robust trajectory planning algorithm for position error. Experimental results for the developed system show that the average directional angle error is 6.82 degrees (standard deviation: 5.98) in the experimental path, which can be stated that it stably navigated the user relatively.

Real-Time Hand Pose Tracking and Finger Action Recognition Based on 3D Hand Modeling (3차원 손 모델링 기반의 실시간 손 포즈 추적 및 손가락 동작 인식)

  • Suk, Heung-Il;Lee, Ji-Hong;Lee, Seong-Whan
    • Journal of KIISE:Software and Applications
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    • v.35 no.12
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    • pp.780-788
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    • 2008
  • Modeling hand poses and tracking its movement are one of the challenging problems in computer vision. There are two typical approaches for the reconstruction of hand poses in 3D, depending on the number of cameras from which images are captured. One is to capture images from multiple cameras or a stereo camera. The other is to capture images from a single camera. The former approach is relatively limited, because of the environmental constraints for setting up multiple cameras. In this paper we propose a method of reconstructing 3D hand poses from a 2D input image sequence captured from a single camera by means of Belief Propagation in a graphical model and recognizing a finger clicking motion using a hidden Markov model. We define a graphical model with hidden nodes representing joints of a hand, and observable nodes with the features extracted from a 2D input image sequence. To track hand poses in 3D, we use a Belief Propagation algorithm, which provides a robust and unified framework for inference in a graphical model. From the estimated 3D hand pose we extract the information for each finger's motion, which is then fed into a hidden Markov model. To recognize natural finger actions, we consider the movements of all the fingers to recognize a single finger's action. We applied the proposed method to a virtual keypad system and the result showed a high recognition rate of 94.66% with 300 test data.