• Title/Summary/Keyword: Matching Size

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Memory-Efficient Belief Propagation for Stereo Matching on GPU (GPU 에서의 고속 스테레오 정합을 위한 메모리 효율적인 Belief Propagation)

  • Choi, Young-Kyu;Williem, Williem;Park, In Kyu
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2012.11a
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    • pp.52-53
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    • 2012
  • Belief propagation (BP) is a commonly used global energy minimization algorithm for solving stereo matching problem in 3D reconstruction. However, it requires large memory bandwidth and data size. In this paper, we propose a novel memory-efficient algorithm of BP in stereo matching on the Graphics Processing Units (GPU). The data size and transfer bandwidth are significantly reduced by storing only a part of the whole message. In order to maintain the accuracy of the matching result, the local messages are reconstructed using shared memory available in GPU. Experimental result shows that there is almost an order of reduction in the global memory consumption, and 21 to 46% saving in memory bandwidth when compared to the conventional algorithm. The implementation result on a recent GPU shows that we can obtain 22.8 times speedup in execution time compared to the execution on CPU.

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Fast Variable-size Block Matching Algorithm for Motion Estimation Based on Bit-pattern (비트패턴을 기반으로 한 고속의 적응적 가변 블록 움직임 예측 알고리즘)

  • 신동식;안재형
    • Journal of Korea Multimedia Society
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    • v.3 no.4
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    • pp.372-379
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    • 2000
  • In this paper, we propose a fast variable-size block matching algorithm for motion estimation based on bit-pattern. Motion estimation in the proposed algorithm is performed after the representation of image sequence is transformed 8bit pixel values into 1bit ones depending on the mean value of search block, which brings a short searching time by reducing the computational complexity. Moreover, adaptive searching methods according to the motion information of the block make the procedure of motion estimation efficient by eliminating an unnecessary searching of low motion block and deepening a searching procedure in high motion block. Experimental results show that the proposed algorithm provides better performance-0.5dB PSNR improvement-than full search block matching algorithm with a fixed block size.

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Development of Noninformative Priors in the Burr Model

  • Cho, Jang-Sik;Kang, Sang-Gil;Baek, Sung-Uk
    • Journal of the Korean Data and Information Science Society
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    • v.14 no.1
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    • pp.83-92
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    • 2003
  • In this paper, we derive noninformative priors for the ratio of parameters in the Burr model. We obtain Jeffreys' prior, reference prior and second order probability matching prior. Also we prove that the noninformative prior matches the alternative coverage probabilities and a HPD matching prior up to the second order, respectively. Finally, we provide simulated frequentist coverage probabilities under the derived noninformative priors for small and moderate size of samples.

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Effective Reconstruction of Stereoscopic Image Pair by using Regularized Adaptive Window Matching Algorithm

  • Ko, Jung-Hwan;Lee, Sang-Tae;Kim, Eun-Soo
    • Journal of Information Display
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    • v.5 no.4
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    • pp.31-37
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    • 2004
  • In this paper, an effective method for reconstruction of stereoscopic image pair through the regularized adaptive disparity estimation is proposed. Although the conventional adaptive disparity window matching can sharply improve the PSNR of a reconstructed stereo image, but there still exist some problems of overlapping between the matching windows and disallocation of the matching windows, because the size of the matching window tend to changes adaptively in accordance with the magnitude of the feature values. In the proposed method, the problems relating to the conventional adaptive disparity estimation scheme can be solved and the predicted stereo image can be more effectively reconstructed by regularizing the extimated disparity vector with the neighboring disparity vectors. From the experimental results, it is found that the proposed algorithm show improvements the PSNR of the reconstructed right image by about 2.36${\sim}$2.76 dB, on average, compared with that of conventional algorithms.

Impedance Matching of Electrically Small Antenna with Ni-Zn Ferrite Film

  • Lee, Jaejin;Hong, Yang-Ki;Lee, Woncheol;Park, Jihoon
    • Journal of Magnetics
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    • v.18 no.4
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    • pp.428-431
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    • 2013
  • We demonstrate that a partial loading of $Ni_{0.5}Zn_{0.5}Fe_2O_4$ (Ni-Zn ferrite) film remarkably improves impedance matching of electrically small $Ba_3Co_2Fe_{24}O_{41}$ ($Co_2Z$) hexaferrite antenna. A 3 ${\mu}m$ thick Ni-Zn ferrite film was deposited on a silicon wafer by the electrophoresis deposition process and post-annealed at $400^{\circ}C$. The fabricated Ni-Zn ferrite film has saturation magnetization of $268emu/cm^3$ and coercivity of 89 Oe. A partial loading of the Ni-Zn ferrite film on the $Co_2Z$ hexaferrite helical antenna increases antenna return loss to 24.7 dB from 9.0 dB of the $Co_2Z$ antenna. Experimental results show that impedance matching and maximum input power transmission to the antenna without additional matching elements can be realized, while keeping almost the same size as the $Co_2Z$ antenna size.

Intensity Gradients-based Stereo Matching of Road Images (에지정보를 이용한 도로영상의 스테레오 정합)

  • 이기용;이준웅
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.1
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    • pp.201-210
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    • 2003
  • In this paper, we propose a new binocular stereo correspondence method by maximizing a fitness formulated by integrating two constraints of edge similarity and disparity smoothness simultaneously. The proposed stereopsis focusing to measure distances to leading vehicles on roads uses intensity gradients as matching attribute. In contrast to the previous work of area-based stereo matching, in which matching unit is a pixel, the matching unit of the proposed method becomes an area itself which is obtained by selecting a series of pixels enclosed by two pixels on the left and right boundaries of an object. This approach allows us to cope with real-time processing and to avoid window size selection problems arising from conventional area-based stereo.

Stereo Matching Using an Adaptive Window Warping

  • Kim, Jae-Chul;Lee, Ho-Keun;Kwon, Sun-Kyu;Ha, Yeong-Ho
    • Proceedings of the IEEK Conference
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    • 2000.07a
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    • pp.421-424
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    • 2000
  • In this paper, we propose a window warping method to solve stereo matching problems in projective distortion region. Because the projective distortion region cant t be estimated with fixed-size block matching algorithm, we use the window warping technique in block matching process. The position of a reference window to resample is obtained adaptively according to the degree of reliability in disparity estimated previously. The initial disparity and reliability are obtained by applying a well known hierarchical strategy. The experimental result shows that considerable improvement is obtained in the projective distortion region.

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Matching Techniques with Land Cover Image for Improving Accuracy of DEM Generation from IKONOS Imagery (IKONOS 영상을 이용한 DEM 추출의 정확도 향상을 위한 토지피복도 활용 정합기법)

  • Lee, Hyo Seong;Park, Byung Uk;Han, Dong Yeob;Ahn, Ki Weon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.1D
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    • pp.153-160
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    • 2009
  • In relation to digital elevation model(DEM) production using high resolution satellite imagery, existing studies present that DEM accuracy differently show according to land cover property. This study therefore proposes auto-selection method of window size for correlation matching according to land cover property of IKONOS Geo-level stereo image. For this, land cover classified image is obtained by IKONOS color image with four bands. In addition, correlation-coefficients are computed at regular intervals in pixels of the window-search area to shorten of matching time. As the results, DEM by the proposed method showed more accurate than DEM using the fixed window-size matching. We estimate that accuracy of the proposed DEM improved more than DEM by digital map and ERDAS in agricultural land.

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.