• Title/Summary/Keyword: Spline interpolation method

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A Study on Image Interpolation Using SOFM and LAM (SOFM과 LAM을 이용한 영상 보간에 관한 연구)

  • Chang, Dong-Eon;Chung, Tae-Sang
    • Proceedings of the KIEE Conference
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    • 1998.11b
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    • pp.640-642
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    • 1998
  • When resampling an image to a new set of coordinates, there is often a noticeable loss in image quality. The interpolation kernel determines the quality of interpolation. In this paper, We think two interpolation methods: cubic-spline method, neural net method, at first study given interpolation method using spline and then present new interpolation methon using SOFM and LAM(neural net method), finally compare the performance of several interpolation methods including replication, bilinear, spline and new methods.

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Interpolation Algorithm Comparison for Contour of Magnified Image (확대 영상의 윤각선 보간 알고리즘 비교)

  • 이용중;김기대;조순조
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.10a
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    • pp.381-386
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    • 2001
  • When a input image is extensively magnified on the computer system, it is almost impossible to replicate the original shape because of mismatched coordinates system. In order to resolve the problem, the shape of the magnified image has been reconfigured using the bilinear interpolation method, low pass special filtering interpolation method and B-spline interpolation method, Ferguson curve interpolation method based on the CAD/CAM curve interpolation algorithm. The computer simulation main result was that. Nearest neighbor interpolation method is simple in making the interpolation program but it is not capable to distinguish the original shape. Bilinear interpolation method has the merit to make the magnified shape smooth and soft but calculation time is longer than the other method. Low pass spatial filtering method and B-spline interpolation method has an effect to immerge the intense of the magnified shape but it is also difficult to distinguish the original shape. Ferguson curve interpolation method has sharping shape than B-spline interpolation method.

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A New Unified Scheme Computing the Quadrature Weights, Integration and Differentiation Matrix for the Spectral Method

  • Kim, Chang-Joo;Park, Joon-Goo;Sung, Sangkyung
    • Journal of Electrical Engineering and Technology
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    • v.10 no.3
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    • pp.1188-1200
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    • 2015
  • A unified numerical method for computing the quadrature weights, integration matrix, and differentiation matrix is newly developed in this study. For this purpose, a spline-like interpolation using piecewise continuous polynomials is converted into a global spline interpolation formula, with which the quadrature formulas can be derived from integration and differentiation of the transformed function in an exact manner. To prove the usefulness of the suggested approach, both the Lagrange and tension spline interpolations are represented in exactly the same form as global spline interpolation. The applicability of the proposed method on arbitrary nodes is illustrated using two different sets of nodes. A series of validations using three test functions is conducted to show the flexibility in selecting computational nodes with the present method.

A Study on the Synthesis of Four-Bur Linkage Generating Automatic Path by Using B-Spline Interpolation (B-스플라인 보간법에 의한 자동 경로 생성이 가능한 4절링크의 합성에 관한 연구)

  • Kim, Jin-Su;Yang, Hyun-Ik
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.10
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    • pp.126-131
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    • 1999
  • Up until now, it is said that no satisfactory computer solutions have been found for synthesizing four-bar linkage based on the prescribed coupler link curve. In our study, an algorithm has been developed to improve the design synthesis of four-bar linkage automatically generating prescribed path by using B-spline interpolation. The suggested algorithm generates the desired coupler curve by using B-spline interpolation, and hence the generated curve approximates as closely as to the desired curve representing coupler link trajectory. Also, when comparing each generated polygon with the control polygon, rapid comparison by applying convex hull concept. finally, optimization process using ADS is incorporated into the algorithm based on the 5 precision point method to reduce the total optimization process time. As for examples, three different four-bar linkages were tested and the results showed the effectiveness of the algorithm.

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Weight Control and Knot Placement for Rational B-spline Curve Interpolation

  • Kim, Tae-Wan;Lee, Kunwoo
    • Journal of Mechanical Science and Technology
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    • v.15 no.2
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    • pp.192-198
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    • 2001
  • We consider an interpolation problem with nonuniform rational B-spline curves given ordered data points. The existing approaches assume that weight for each point is available. But, it is not the case in practical applications. Schneider suggested a method which interpolates data points by automatically determining the weight of each control point. However, a drawback of Schneiders approach is that there is no guarantee of avoiding undesired poles; avoiding negative weights. Based on a quadratic programming technique, we use the weights of the control points for interpolating additional data. The weights are restricted to appropriate intervals; this guarantees the regularity of the interpolating curve. In a addition, a knot placement is proposed for pleasing interpolation. In comparison with integral B-spline interpolation, the proposed scheme leads to B-spline curves with fewer control points.

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3D Image Process by Template Matching and B-Spline Interpolations (템플릿 정합과 B-Spline 보간에 의한 3차원 광학 영상 처리)

  • Joo, Young-Hoon;Yang, Han-Jin
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.5
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    • pp.683-688
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    • 2009
  • The purposes of this paper is to propose new techniques to reconstruct measured optical images by using the template matching and B-Spline interpolation method based on image processing technology. To do this, we detect the matching template and non-matching template from each optical image. And then, we match the overlaped images from base level by correcting roll, pitch, and yaw error of images. At last, the matching image is interpolated by B-Spline interpolation. Finally, we show the effectiveness and feasibility of the proposed method through some experiments.

Reconstruction of the Undersampled Photoplethysmogram with Various Interpolation Methods (보간 방법에 따른 언더샘플링된 광용적맥파 복원 가능성 평가)

  • Shin, Hangsik;Kim, Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.8
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    • pp.1418-1423
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    • 2016
  • The purpose of this research is to investigate the effect of sampling frequency on the photoplethysmography (PPG) and to evaluate the performance of interpolation methods for under-sampled PPG. We generated down-sampled PPG using 10 kHz-sampled PPG then evaluated waveshape changes with correlation coefficient. Correlation coefficient was significantly decreased at 50 Hz or below sampling frequency. We interpolated the down-sampled PPG using four interpolation method-linear, nearest, cubic spline and piecewise cubic Hermitt interpolation polynomial - then evaluated interpolation performance. As a result, it was shown that PPG waveform that was sampled over 20 Hz could be reconstructed by interpolation. Among interpolation methods, cubic spline interpolation showed the highest performance. However, every interpolation method has no or less effect on 5 Hz sampled PPG.

Method of Fast Interpolation of B-Spline Volumes for Reconstructing the Heterogeneous Model of Bones from CT Images (CT 영상에서 뼈의 불균질 모델 생성을 위한 B-스플라인 볼륨의 빠른 보간 방법)

  • Park, Jun Hong;Kim, Byung Chul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.4
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    • pp.373-379
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    • 2016
  • It is known that it is expedient to represent the distribution of the properties of a bone with complex heterogeneity as B-spline volume functions. For B-spline-based representation, the pixel values of CT images are interpolated by B-spline volume functions. However, the CT images of a bone are three-dimensional and very large, and hence a large amount of memory and long computation time for the interpolation are required. In this study, a method for resolving these problems is proposed. In the proposed method, the B-spline volume interpolation problem is simplified by using the uniformity of pixel spacing of the image and the properties of B-spline basis functions. This results in a reduction in computation time and the amount of memory used. The proposed method was implemented and it was verified that the computation time and the amount of memory used were reduced.

Comparison of the Results of Finite Difference Method in One-Dimensional Advection-Dispersion Equation (유한차분 모형에 의한 일차원 이송-확산방정식 계산결과의 비교)

  • 이희영;이재철
    • Water for future
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    • v.28 no.4
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    • pp.125-136
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    • 1995
  • ELM, a characteristic line based method, was applied to advection-dispersion equation, and the results obtained were compared with those of Eulerian schemes(Stone-Brian and QUICKEST). The calculation methods consisted of Lagrangian interpolation scheme and cubic spline interpolation scheme for the advection calculation, and the Crank-Nicholson scheme for the dispersion calculation. The results of numerical methods were as follows: (1) for Gaussian hill: ELM, using Lagrangian interpolation scheme, gave the most accurate computational result, ELM, using cubic spline interpolation scheme, and QUICKEST scheme gave numerical damping for Peclet number 50. Stone-Brian scheme gave phase shift introduced in the numerical solution for Peclet number 10 and 50. (2) for advanced front: All schemes gave accurate computational results for Peclet number 1 and 4. ELM, Lagrangian interpolation scheme, and Stone,Brian scheme gave dissipation error and ELM, using cubic spline interpolation scheme, and QUICKEST scheme gave numerical oscillation for Peclet number 50.

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