• Title/Summary/Keyword: 워핑함수

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Effective Compression Technique of Multi-view Image expressed by Layered Depth Image (계층적 깊이 영상으로 표현된 다시점 영상의 효과적인 압축 기술)

  • Jee, Inn-Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.29-37
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    • 2014
  • Since multi-view video exists a number of camera color image and depth image, it has a huge of data. Thus, a new compression technique is indispensable for reducing this data. Recently, the effective compression encoding technique for multi-view video that used in layered depth image concepts is a remarkable. This method uses several view point of depth information and warping function, synthesizes multi-view color and depth image, becomes one data structure. In this paper we use actual distance for solving overlap in layered depth image that reduce required data for reconstructing in color-based transform. In experimental results, we confirmed high compression performance and good quality of reconstructed image.

Feature-Based Deformation of 3D Facial Model Using Radial Basis Function (Radial Basis Function 을 이용한 특징점 기반 3 차원 얼굴 모델의 변형)

  • Kwon Oh-Ryun;Min Kyong-Pil;Chun Jun-Chul
    • Proceedings of the Korea Information Processing Society Conference
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    • 2006.05a
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    • pp.715-718
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    • 2006
  • 아바타를 이용한 얼굴 애니메이션은 가상 현실이나 엔터테인먼트와 같은 분야에서 많이 적용된다. 얼굴 애니메이션을 생성하는 방법에는 크게 3 차원 모델을 직접 변형시키는 기하학적인 변형 방법과 2 차원 이미지의 워핑이나 모핑방법을 이용한 이미지 변형 방법이 있다. 기하학적인 변형 방법 중 3 차원 모델을 변형시키기 위한 방법으로 RBF(Radial Basis Function)을 이용하는 방법이 있다. RBF 함수를 이용하여 모델의 부드러운 변형을 만들 수 있다. 이 방법은 모델의 임의의 한 점을 이동하게 되면 영향을 받는 정점들을 좀 더 자연스럽게 이동시킴으로써 자연스러운 애니메이션을 생성할 수 있다. 본 연구에서는 RBF 를 이용하여 3 차원 얼굴 메쉬 모델의 기하학적 변형을 통해 모델의 얼굴 표정을 생성하는 방법에 대해 제안하고자 한다. 얼굴 모델 변형을 위해 얼굴의 특징인 눈, 입, 턱 부분에 특징점을 정하고 각 특징점에 따라 영향을 받는 영역을 정하기 위해 얼굴 모델을 지역적으로 클러스터링한다. 각 특징점에 따라 영향을 받는 영역에 대해 클러스터링을 적용하고 RBF 를 이용하여 자연스러운 얼굴 표정을 생성하는 방법을 제안한다.

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An Efficient Crosstalk Cancellation Algorithm Using Pole-zero Dewarping (Pole-zero Dewarping을 이용한 효율적인 Crosstalk 제거 알고리듬)

  • Lee Junho;Park Young-cheol;Youn Dae-hee;Jeong Jae-woong
    • The Journal of the Acoustical Society of Korea
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    • v.24 no.3
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    • pp.133-140
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    • 2005
  • Crosstalk canceller in stereo channel audio reproduction system has the purpose to deliver desired signals exactly at the listener's ear. Generally. it has a Poor performance in low frequency bands. Frequency-warped Otters are used to provide improved performance in crosstalk canceller for these problems. However. such filters are more complex to implement than conventional filters. This paper presents an efficient method for low-order IIR approximation of frequency warped crosstalk cancellation filters using Pole-zero dewarping. The method preserves the advantages of frequency warping, but has a computational complexity that is similar to the conventional method. This Paper also presents a series of experiments that validate the method of crosstalk canceller.

A Boundary-layer Stress Analysis of Laminated Composite Beams via a Computational Asymptotic Method and Papkovich-Fadle Eigenvector (전산점근해석기법과 고유벡터를 이용한 복합재료 보의 경계층 응력 해석)

  • Sin-Ho Kim;Jun-Sik Kim
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.37 no.1
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    • pp.41-47
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    • 2024
  • This paper utilizes computational asymptotic analysis to compute the boundary layer solution for composite beams and validates the findings through a comparison with ANSYS results. The boundary layer solution, presented as a sum of the interior solution and pure boundary layer effects, necessitates a mathematically rigorous formalization for both interior and boundary layer aspects. Computational asymptotic analysis emerges as a robust technique for addressing such problems. However, the challenge lies in connecting the boundary layer and interior solutions. In this study, we systematically separate the principles of virtual work and the principles of Saint-Venant to tackle internal and boundary layer issues. The boundary layer solution is articulated by calculating the Papkovich-Fadle eigenfunctions, representing them as linear combinations of real and imaginary vectors. To address warping functions in the interior solutions, we employed a least squares method. The computed solutions exhibit excellent agreement with 2D finite element analysis results, both quantitatively and qualitatively. This validates the effectiveness and accuracy of the proposed approach in capturing the behavior of composite beams.

HummingBird: A Similar Music Retrieval System using Improved Scaled and Warped Matching (HummingBird: 향상된 스케일드앤워프트 매칭을 이용한 유사 음악 검색 시스템)

  • Lee, Hye-Hwan;Shim, Kyu-Seok;Park, Hyoung-Min
    • Journal of KIISE:Databases
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    • v.34 no.5
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    • pp.409-419
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    • 2007
  • Database community focuses on the similar music retrieval systems for music database when a humming query is given. One of the approaches is converting the midi data to time series, building their indices and performing the similarity search on them. Queries based on humming can be transformed to time series by using the known pitch detection algorithms. The recently suggested algorithm, scaled and warped matching, is based on dynamic time warping and uniform scaling. This paper proposes Humming BIRD(Humming Based sImilaR mini music retrieval system) using sliding window and center-aligned scaled and warped matching. Center-aligned scaled and warped matching is a mixed distance measure of center-aligned uniform scaling and time warping. The newly proposed measure gives tighter lower bound than previous ones which results in reduced search space. The empirical results show the superiority of this algorithm comparing the pruning power while it returns the same results.

A Study on Calculation of Cross-Section Properties for Composite Rotor Blades Using Finite Element Method (유한요소법 기반의 복합재료 블레이드 단면 특성치 계산에 관한 연구)

  • Park, Il-Ju;Jung, Sung-Nam;Cho, Jin-Yeon;Kim, Do-Hyung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.5
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    • pp.442-449
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    • 2009
  • A two-dimensional cross-section analysis program based on the finite element method has been developed for composite blades with solid, thin-walled and compound cross-sections. The weighted-modulus method is introduced to determine the laminated composite material properties. The shear center and the torsion constant for any given section are calculated according to the Trefftz' definition and the St. Venant torsion theory, respectively. The singular value problem of cross-section stiffness properties faced during the section analysis has been solved by performing an eigenvalue analysis to remove the rigid body mode. Numerical results showing the accuracy of the program obtained for stiffness, offset and inertia properties are compared in this analysis. The current analysis results are validated with those obtained by commercial software and published data available in the literature and a good correlation has generally been achieved through a series of validation study.

Hole-Filling Method Using Extrapolated Spatio-temporal Background Information (추정된 시공간 배경 정보를 이용한 홀채움 방식)

  • Kim, Beomsu;Nguyen, Tien Dat;Hong, Min-Cheol
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.8
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    • pp.67-80
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    • 2017
  • This paper presents a hole-filling method using extrapolated spatio-temporal background information to obtain a synthesized view. A new temporal background model using non-overlapped patch based background codebook is introduced to extrapolate temporal background information In addition, a depth-map driven spatial local background estimation is addressed to define spatial background constraints that represent the lower and upper bounds of a background candidate. Background holes are filled by comparing the similarities between the temporal background information and the spatial background constraints. Additionally, a depth map-based ghost removal filter is described to solve the problem of the non-fit between a color image and the corresponding depth map of a virtual view after 3-D warping. Finally, an inpainting is applied to fill in the remaining holes with the priority function that includes a new depth term. The experimental results demonstrated that the proposed method led to results that promised subjective and objective improvement over the state-of-the-art methods.

Acceleration of Feature-Based Image Morphing Using GPU (GPU를 이용한 특징 기반 영상모핑의 가속화)

  • Kim, Eun-Ji;Yoon, Seung-Hyun;Lee, Jieun
    • Journal of the Korea Computer Graphics Society
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    • v.20 no.2
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    • pp.13-24
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    • 2014
  • In this study, a graphics-processing-unit (GPU)-based acceleration technique is proposed for the feature-based image morphing. This technique uses the depth-buffer of the graphics hardware to calculate efficiently the shortest distance between a pixel and the control lines. The pairs of control lines between the source image and the destination image are determined by user's input, and the distance function of each control line is rendered using two rectangles and two cones. The distance between each pixel and its nearest control line is stored in the depth buffer through the graphics pipeline, and this is used to conduct the morphing operation efficiently. The pixel-unit morphing operation is parallelized using the compute unified device architecture (CUDA) to reduce the morphing time. We demonstrate the efficiency of the proposed technique using several experimental results.