• Title/Summary/Keyword: Curvature Extrema

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Recognition of Profile Contours of Human Face by Approximation - Recognition

  • Yang, Yun-Mo
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.683-686
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    • 1988
  • In the recognition of similar patterns like profile contours of human faces, feature measure plays important role. We extracted effective and general feature by B-spline approximation. The nodes and vertices of the approximated curve are normalized and used as features. Since the features have both local property of curvature extrema and global property by B-spline approximation, they are superior to those of curvature extrema of the profile contour. For the image data of six sets of 56 persons, some of which are ill-made, averaged accuracy rate of 97.6 % is obtained in recognizing combinational 333 test samples.

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Image matching by Wavelet Local Extrema (웨이브릿 국부 최대-최소값을 이용한 영상 정합)

  • 박철진;김주영;고광식
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.589-592
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    • 1999
  • Matching is a key problem in computer vision, image analysis and pattern recognition. In this paper a multiscale image matching algorithm by wavelet local extrema is proposed. This algorithm is based on the multiscale wavelet transform of the curvature which can utilize both the information of local extrema positions and magnitudes of transform results. This method has advantages in computational cost to a single scale image matching. It is also rotation-, translation-, and scale-independent image matching method. This matching can be used for the recognition of occluded objects.

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Recognition of Profile Contours of Human Face by Approximation - Approximation -

  • Yang, Yun-Mo
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.679-682
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    • 1988
  • From the viewpoint of general recognition system, B-spline is introduced for the approximation and recognition of human profile contours. Profile contour is approximated to the cublic B-spline curve by least square fitting so that B-Spline nodes nearly correspond with the curvature extrema of the contour. This method is designed for the spline to be good features in recognition, and also showed good approximation compared with the variants of B-spline appraximation.

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Curvature Based ECG Signal Compression for Effective Communication on WPAN

  • Kim, Tae-Hun;Kim, Se-Yun;Kim, Jeong-Hong;Yun, Byoung-Ju;Park, Kil-Houm
    • Journal of Communications and Networks
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    • v.14 no.1
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    • pp.21-26
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    • 2012
  • As electrocardiogram (ECG) signals are generally sampled with a frequency of over 200 Hz, a method to compress diagnostic information without losing data is required to store and transmit them efficiently on a wireless personal area network (WPAN). In this paper, an ECG signal compression method for communications onWPAN, which uses feature points based on curvature, is proposed. The feature points of P, Q, R, S, and T waves, which are critical components of the ECG signal, have large curvature values compared to other vertexes. Thus, these vertexes were extracted with the proposed method, which uses local extrema of curvatures. Furthermore, in order to minimize reconstruction errors of the ECG signal, extra vertexes were added according to the iterative vertex selectionmethod. Through the experimental results on the ECG signals from Massachusetts Institute of Technology-Beth Israel hospital arrhythmia database, it was concluded that the vertexes selected by the proposed method preserved all feature points of the ECG signals. In addition, it was more efficient than the amplitude zone time epoch coding method.