• Title/Summary/Keyword: shape detection

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Damage Detection in a Bean Via the Wavelet Transform of Mode Shapes (모드형상의 웨이블렛 변환을 이용한 보의 결함 진단)

  • Lee, Yong-Uk;Kim, Yun-Yeong;Lee, Ho-Cheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.4 s.175
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    • pp.916-925
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    • 2000
  • Perhaps, this is the first attempt which applies the wavelet transform to the fundamental vibration mode for damage detection in a beam. Contrary to most existing detection methods on mode shapes, the present method directly works only with the fundamental mode of a damaged beam: no vibration mode shape of a undamaged beam is necessary. Applying the concept of vanishing moments of wavelet functions, we show that wavelet functions are effective damage detectors. Both numerical and experimental results confirm the effectiveness of the present method.

Chessboard and Pieces Detection for Janggi Chess Playing Robot

  • Nhat, Vo Quang;Lee, GueeSang
    • International Journal of Contents
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    • v.9 no.4
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    • pp.16-21
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    • 2013
  • Vision system is an indispensable part of constructing the chess-playing robot. Chessboard detection and pieces localization in the captured image of robot's camera are important steps for processes followed such as pieces recognition, move calculation, and robot controlling. We present a method for detecting the Janggi chessboard and pieces based on the edge and color feature. Hough transform combined with line extraction is used for segmenting the chessboard and warping it to form the rectangle shape in order to detect and interpolate the lines of chessboard. Then we detect the existence of pieces and their side by applying the saliency map and checking the color distribution at piece locations. While other methods either work only with the empty chessboard or do not care about the piece existence, our method could detect sufficiently side and position of pieces as well as lines of the chessboard even if the occlusion happens.

DETECTION OF FACIAL FEATURES IN COLOR IMAGES WITH VARIOUS BACKGROUNDS AND FACE POSES

  • Park, Jae-Young;Kim, Nak-Bin
    • Journal of Korea Multimedia Society
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    • v.6 no.4
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    • pp.594-600
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    • 2003
  • In this paper, we propose a detection method for facial features in color images with various backgrounds and face poses. To begin with, the proposed method extracts face candidacy region from images with various backgrounds, which have skin-tone color and complex objects, via the color and edge information of face. And then, by using the elliptical shape property of face, we correct a rotation, scale, and tilt of face region caused by various poses of head. Finally, we verify the face using features of face and detect facial features. In our experimental results, it is shown that accuracy of detection is high and the proposed method can be used in pose-invariant face recognition system effectively

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Projected Local Binary Pattern based Two-Wheelers Detection using Adaboost Algorithm

  • Lee, Yeunghak;Kim, Taesun;Shim, Jaechang
    • Journal of Multimedia Information System
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    • v.1 no.2
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    • pp.119-126
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    • 2014
  • We propose a bicycle detection system riding on people based on modified projected local binary pattern(PLBP) for vision based intelligent vehicles. Projection method has robustness for rotation invariant and reducing dimensionality for original image. The features of Local binary pattern(LBP) are fast to compute and simple to implement for object recognition and texture classification area. Moreover, We use uniform pattern to remove the noise. This paper suggests that modified LBP method and projection vector having different weighting values according to the local shape and area in the image. Also our system maintains the simplicity of evaluation of traditional formulation while being more discriminative. Our experimental results show that a bicycle and motorcycle riding on people detection system based on proposed PLBP features achieve higher detection accuracy rate than traditional features.

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Dominant Color Transform and Circular Pattern Vector: Applications to Traffic Sign Detection and Symbol Recognition

  • An, Jung-Hak;Park, Tae-Young
    • Journal of Electrical Engineering and information Science
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    • v.3 no.1
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    • pp.73-79
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    • 1998
  • In this paper, a new traffic sign detection algorithm.. and a symbol recognition algorithm are proposed. For traffic sign detection, a dominant color transform is introduced, which serves as a tool of highlighting a dominant primary color, while discarding the other two primary colors. For symbol recognition, the curvilinear shape distribution on a circle centered on the centroid of symbol, called a circular pattern vector, is used as a spatial feature of symbol. The circular pattern vector is invariant to scaling, translation, and rotation. As simulation results, the effectiveness of traffic sign detection and recognition algorithms are confirmed, and it is shown that group of circular patter vectors based on concentric circles is more effective than circular pattern vector of a single circle for a given equivalent number of elements of vectors.

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A Study on Linear Spectral Mixing Model for Hyperspectral Imagery with Geometric Method (기하학적 기법을 이용한 하이퍼스펙트럴 영상의 Linear Spectral Mixing모델에 관한 연구)

  • 장은석;김대성;김용일
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2003.11a
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    • pp.23-29
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    • 2003
  • Detection in remotely sensed images can be conducted spatially, spectrally or both [2]. If the images have high spatial resolution, materials can be detected by using spatial and spectral information, unless we can't see the object embedded in a pixel. In this paper, we intend to solve the limit of spatial resolution by using the hyperspectral image which has high spectral resolution. Therefore, the Linear Spectral Mixing(LSM) Model which is sub-pixel detection algorithm is used to solve this problem. To find class Endmembers, we applied Geometric Model with MNF(Minimum Noise Fraction) transformation. From the result of sub-pixel detection algorithm, we can see the detection of water is satisfied and the object shape cannot be extracted but the possibility of material existence can be identified.

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Traffic Light Detection Method in Image Using Geometric Analysis Between Traffic Light and Vision Sensor (교통 신호등과 비전 센서의 위치 관계 분석을 통한 이미지에서 교통 신호등 검출 방법)

  • Choi, Changhwan;Yoo, Kook-Yeol;Park, Yongwan
    • IEMEK Journal of Embedded Systems and Applications
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    • v.10 no.2
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    • pp.101-108
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    • 2015
  • In this paper, a robust traffic light detection method is proposed by using vision sensor and DGPS(Difference Global Positioning System). The conventional vision-based detection methods are very sensitive to illumination change, for instance, low visibility at night time or highly reflection by bright light. To solve these limitations in visual sensor, DGPS is incorporated to determine the location and shape of traffic lights which are available from traffic light database. Furthermore the geometric relationship between traffic light and vision sensor is used to locate the traffic light in the image by using DGPS information. The empirical results show that the proposed method improves by 51% in detection rate for night time with marginal improvement in daytime environment.

Smoke Detection System Research using Fully Connected Method based on Adaboost

  • Lee, Yeunghak;Kim, Taesun;Shim, Jaechang
    • Journal of Multimedia Information System
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    • v.4 no.2
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    • pp.79-82
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    • 2017
  • Smoke and fire have different shapes and colours. This article suggests a fully connected system which is used two features using Adaboost algorithm for constructing a strong classifier as linear combination. We calculate the local histogram feature by gradient and bin, local binary pattern value, and projection vectors for each cell. According to the histogram magnitude, this paper applied adapted weighting value to improve the recognition rate. To preserve the local region and shape feature which has edge intensity, this paper processed the normalization sequence. For the extracted features, this paper Adaboost algorithm which makes strong classification to classify the objects. Our smoke detection system based on the proposed approach leads to higher detection accuracy than other system.

An Efficient Edge Detection Using Van der Waerden′s Statistic in Images (Van der Waerden의 통계량을 이용한 영상에서의 효율적인 에지검출기법)

  • 최명희;이호근;김주원;하영호
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.215-218
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    • 2002
  • The edges of an image hold much of the information in that image. The edges tell where objects are, their shape and size, and something about their texture. An edge is where the intensity of an image moves from a low value to a high value. We introduce the edge detection using the differential operator with Sobel operator and describe a nonparametric Wilcoxon test based on statistical hypothesis testing for the detection of edges. This paper proposes an efficient edge detection using Van der Waerden's statistic in original and noisy images. We use the threshold determined by specifying significance level a and an edge-height parameter. Comparison with our statistical test and Sobel operator shows that Van der Waerden method perform more effectively in both noisy and noise-free images.

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Damage detection in beams and plates using wavelet transforms

  • Rajasekaran, S.;Varghese, S.P.
    • Computers and Concrete
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    • v.2 no.6
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    • pp.481-498
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    • 2005
  • A wavelet based approach is proposed for structural damage detection in beams, plate and delamination of composite plates. Wavelet theory is applied here for crack identification of a beam element with a transverse on edge non-propagating open crack. Finite difference method was used for generating a general displacement equation for the cracked beam in the first example. In the second and third example, damage is detected from the deformed shape of a loaded simply supported plate applying the wavelet theory. Delamination in composite plate is identified using wavelet theory in the fourth example. The main concept used is the breaking down of the dynamic signal of a structural response into a series of local basis function called wavelets, so as to detect the special characteristics of the structure by scaling and transformation property of wavelets. In the light of the results obtained, limitations of the proposed method as well as suggestions for future work are presented. Results show great promise of wavelet approach for damage detection and structural health monitoring.