• Title/Summary/Keyword: Variable Window

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A Variable Window Method for Three-Dimensional Structure Reconstruction in Stereo Vision (삼차원 구조 복원을 위한 스테레오 비전의 가변윈도우법)

  • 김경범
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.7
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    • pp.138-146
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    • 2003
  • A critical issue in area-based stereo matching lies in selecting a fixed rectangular window size. Previous stereo methods doesn't deal effectively with occluding boundary due to inevitable window-based problems, and so give inaccurate and noisy matching results in areas with steep disparity variations. In this paper, a variable window approach is presented to estimate accurate, detailed and smooth disparities for three-dimensional structure reconstruction. It makes the smoothing of depth discontinuity reduced by evaluating corresponding correlation values and intensity gradient-based similarity in the three-dimensional disparity space. In addition, it investigates maximum connected match candidate points and then devise the novel arbitrarily shaped variable window representative of a same disparity to treat with disparity variations of various structure shapes. We demonstrate the performance of the proposed variable window method with synthetic images, and show how our results improve on those of closely related techniques for accuracy, robustness, matching density and computing speed.

A Variable Window Method with Three-Dimensional Disparity Space (삼차원 변이 공간을 이용한 가변윈도우법)

  • 김경범;이홍서
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.284-287
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    • 2003
  • Previous stereo methods doesn't deal effectively with depth discontinuity due to inevitable window-based problems, and so give inaccurate and noisy matching results in areas with steep disparity variations. In this paper. a variable window approach is presented to estimate accurate, detailed and smooth disparities with three-dimensional disparity space. It makes the smoothing of depth discontinuity reduced by evaluating corresponding correlation values and intensity gradient-based similarity in the space. In addition, it devises the novel arbitrarily-shaped variable window to treat with disparity variations of various structure shapes. We show how our results improve on those of closely related techniques for accuracy, robustness. matching density and computing speed.

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Robust Tracking Algorithm for Moving Object using Kalman Filter and Variable Search Window Technique (칼만 필터와 가변적 탐색 윈도우 기법을 적용한 강인한 이동 물체 추적 알고리즘)

  • Kim, Young-Kyun;Hyeon, Byeong-Yong;Cho, Young-Wan;Seo, Ki-Sung
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.7
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    • pp.673-679
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    • 2012
  • This paper introduces robust tracking algorithm for fast and erratic moving object. CAMSHIFT algorithm has less computation and efficient performance for object tracking. However, the method fails to track a object if it moves out of search window by fast velocity and/or large movement. The size of the search window in CAMSHIFT algorithm should be selected manually also. To solve these problems, we propose an efficient prediction technique for fast movement of object using Kalman Filter with automatic initial setting and variable configuration technique for search window. The proposed method is compared to the traditional CAMSHIFT algorithm for searching and tracking performance of objects on test image frames.

A Dynamic Variable Window-based Topographical Classification Method Using Aerial LiDAR Data (항공 라이다 데이터를 이용한 동적 가변 윈도우 기반 지형 분류 기법)

  • Sung, Chul-Woong;Lee, Sung-Gyu;Park, Chang-Hoo;Lee, Ho-Jun;Kim, Yoo-Sung
    • Spatial Information Research
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    • v.18 no.5
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    • pp.13-26
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    • 2010
  • In this paper, a dynamic variable window-based topographical classification method is proposed which has the changeable classification units depending on topographical properties. In the proposed scheme, to im prove the classification efficiency, the unit of topographical classification can be changeable dynamically according to the topographical properties and repeated patterns. Also, in this paper, the classification efficiency and accuracy of the proposed method are analyzed in order to find an optimal maximum decision window-size through the experiment. According to the experiment results, the proposed dynamic variable window-based topographical classification method maintains similar accuracy but remarkably reduce computing time than that of a fixed window-size based one, respectively.

Ultra-fast Adaptive Frequency-controlled Hysteretic Buck Converter for Portable Devices

  • Kim, Kwang-Ho;Kong, Bai-Sun
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.5
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    • pp.615-623
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    • 2016
  • The paper describes a hysteretic buck converter including a differentiator and an adaptive hysteresis window controller. Differentiating the feedback signal achieves ultra-fast switching of the buck converter. The adaptive hysteresis window control allows a monotonous operation with predictable noise spectrum, and gives way to efficient design for variable supply and output voltages. The measurement results in a $0.13-{\mu}m$ CMOS process indicated that the switching frequency became double times higher, and the voltage ripple was reduced by up to 69%. They also indicated that the normalized switching frequency variation was reduced by 74% with variable $V_{DD}$ and by 63% with variable $V_{OUT}$. The power efficiency was improved by 3.5% depending on loading condition.

Reusing Search Window Data and Exploiting Early Termination in Variable Block Size Motion Estimation (가변 블록 크기 움직임 추정 기법에서 탐색 영역 데이터의 재사용과 조기 중단 기법의 적용)

  • Park, Taewook;Hur, Ahrum;Lee, Seongsoo
    • Journal of IKEEE
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    • v.20 no.1
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    • pp.111-114
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    • 2016
  • In HEVC, motion estimation is performed independently for each variable block size. So it requires several times of search window data, and also it is difficult to exploit early termination. In this paper, a new method is proposed to exploit search window data and early termination in variable block size. When applied to TZS algorithm, it reduces pixel comparison and search window data accesses to 1/3.7 ~ 1/2.9 with negligible image quality degradation.

Design and Performance Evaluation of Hybrid Window Walls With Variable Transmittal Materials (투과시스템의 광학특성을 고려한 복합적 외벽채광부의 성능평가에 관한 연구)

  • Do, Jin-Seok;Kim, Gon;Kim, Jeong Tai
    • KIEAE Journal
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    • v.4 no.2
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    • pp.11-18
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    • 2004
  • Growing use of entire glass facades with metal frames are popularly witnessed in modern building practices and design competition as well. In spite of architectural aesthetics and view to outdoors, environmental issues still exist in that kind of buildings. One of the solutions for the problems might be the use of functional glasses such as a heat-resistant glass or various tinted glasses for the glass walls. This paper aims to provide performance data related to the impact of various transmittal materials of window systems on the light distribution. A series of computer simulation deals with the basic geometrical and optical design elements of a commonly used all-glass facades. Additionally an experimental configuration of the vertical window is proposed for better result of daylighting. A window system equipped with an inner-light shelf can improve the uniformity of natural light in a space by reducing the level of illumination near the window and redirecting light deeply into the space.

A delay estimation-based synchronization protocol for multimedia services in ATM networks (ATM망에서 멀티미디어 서비스를 위한 지연 예측 기반 동기화 프로토콜)

  • 이동은;강인곤;김영선;김영천
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.5
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    • pp.31-43
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    • 1996
  • In this paper, we analyze the delay characteristics of the multimdedia traffic in B-ISDN, and propose a weighted variable-size window estimator considering the QoS characteristics of the media and the variable delay characteristics of the networks, and present a delay estimator-based synchronization protocol for the efficient synchronization in ATM-based B-ISDN. The proposed estimator assigns a high weight value to recent cells arrived in the receiver, and suitably adjusts window size in order to efficiently adapt to delay variation by the prameter to detect the delay variation of the networks. The proposed synchronization protocol estimates end-to-end delay by the weighted variable-size window estimator, and dynamically schedules th evirtual channel of the transmitter to playout multimedia data on time in the receiver. Also, we evaluate the performance of the delay estimator, which is the most importnat functional element in our proposed synchronization protocol, by the simulation and analyze the results of the simulation.

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Study on Estimate of Window Condensation performance Due to Temperature Depreciation Ratio (표면 온도 저하율에 따른 창호부 결로성능 예측에 관한 연구)

  • Sung, Uk-Joo;Cho, Soo;Jang, Cheul-Yong;Lee, Jin-Seong;Peak, Sang-Hun
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.1255-1260
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    • 2006
  • This present study analyzed temperature depreciation ratio of window inside surface by KS F 2295 'Procedure for determining fenestration product condensation resistance values'. it estimated window indoor surface condensation due to variable environmental condition. Performance of condensation resistance by using temperature depreciation ratio until applied Low-e and Ar glazing improved about 45% from 24 mm clear. Temperature depreciation ratio by KS F 2295 considers analytic index of window condensation due to variable boundary condition.

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A New Stereo Matching Algorithm based on Variable Windows using Frequency Information in DWT Domain (DWT 영역에서의 주파수 정보를 활용한 가변 윈도우 기반의 스테레오 정합 알고리즘)

  • Seo, Young-Ho;Koo, Ja-Myung;Kim, Dong-Wook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.7
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    • pp.1437-1446
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    • 2012
  • In this paper we propose a new stereo matching algorithm which is suitable for application to obtain depth information with high-speed in stereoscopic camera environment. For satisfying these condition we propose a new adaptive stereo matching technique using frequency information in discrete wavelet (DWT) domain and variable matching window. The size of the matching window is selected by analysis of the local property of the image in spatial domain and the feature and scaling factor of the matching window is selected by the frequency property in the frequency domain. For using frequency information we use local DWT and global DWT. We identified that the proposed technique has better peak noise to signal ratio (PSNR) than the fixed matching techniques with similar complexity.