• Title/Summary/Keyword: Edge method

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Optical Flow Measurement Based on Boolean Edge Detection and Hough Transform

  • Chang, Min-Hyuk;Kim, Il-Jung;Park, Jong an
    • International Journal of Control, Automation, and Systems
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    • v.1 no.1
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    • pp.119-126
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    • 2003
  • The problem of tracking moving objects in a video stream is discussed in this pa-per. We discussed the popular technique of optical flow for moving object detection. Optical flow finds the velocity vectors at each pixel in the entire video scene. However, optical flow based methods require complex computations and are sensitive to noise. In this paper, we proposed a new method based on the Hough transform and on voting accumulation for improving the accuracy and reducing the computation time. Further, we applied the Boo-lean based edge detector for edge detection. Edge detection and segmentation are used to extract the moving objects in the image sequences and reduce the computation time of the CHT. The Boolean based edge detector provides accurate and very thin edges. The difference of the two edge maps with thin edges gives better localization of moving objects. The simulation results show that the proposed method improves the accuracy of finding the optical flow vectors and more accurately extracts moving objects' information. The process of edge detection and segmentation accurately find the location and areas of the real moving objects, and hence extracting moving information is very easy and accurate. The Combinatorial Hough Transform and voting accumulation based optical flow measures optical flow vectors accurately. The direction of moving objects is also accurately measured.

Stress intensity factors for periodic edge cracks in a semi-infinite medium with distributed eigenstrain

  • Afsar, A.M.;Ahmed, S.R.
    • Structural Engineering and Mechanics
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    • v.21 no.1
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    • pp.67-82
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    • 2005
  • This study analyzes stress intensity factors for a number of periodic edge cracks in a semiinfinite medium subjected to a far field uniform applied load along with a distribution of eigenstrain. The eigenstrain is considered to be distributed arbitrarily over a region of finite depth extending from the free surface. The cracks are represented by a continuous distribution of edge dislocations. Using the complex potential functions of the edge dislocations, a simple as well as effective method is developed to calculate the stress intensity factor for the edge cracks. The method is employed to obtain the numerical results of the stress intensity factor for different distributions of eigenstrain. Moreover, the effect of crack spacing and the intensity of the normalized eigenstress on the stress intensity factor are investigated in details. The results of the present study reveal that the stress intensity factor of the periodic edge cracks is significantly influenced by the magnitude as well as distribution of the eigenstrain within the finite depth. The eigenstrains that induce compressive stresses at and near the free surface of the semi-infinite medium reduce the stress intensity factor that, in turn, contributes to the toughening of the material.

Low Complexity Hybrid Interpolation Algorithm using Weighted Edge Detector (가중치 윤곽선 검출기를 이용한 저 복잡도 하이브리드 보간 알고리듬)

  • Kwon, Hyeok-Jin;Jeon, Gwang-Gil;Jeong, Je-Chang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.3C
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    • pp.241-248
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    • 2007
  • In predictive image coding, a LS (Least Squares)-based adaptive predictor is an efficient method to improve image edge predictions. This paper proposes a hybrid interpolation with weighted edge detector. A hybrid approach of switching between bilinear interpolation and EDI (Edge-Directed Interpolation) is proposed in order to reduce the overall computational complexity The objective and subjective quality is also similar to the bilinear interpolation and EDI. Experimental results demonstrate that this hybrid interpolation method that utilizes a weighted edge detector can achieve reduction in complexity with minimal degradation in the interpolation results.

A Study on the step edge detection method based on image information measure and eutral network (영상의 정보척도와 신경회로망을 이용한 계단에지 검출에 관한 연구)

  • Lee, S.B.;Kim, S.G.
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.3
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    • pp.549-555
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    • 2006
  • An edge detection is an very important area in image processing and computer vision, General edge detection methods (Robert mask, Sobel mask, Kirsh mask etc) are a good performance to detect step edge in a image but are no good performance to detect step edge in a noses image. We suggested a step edge detection method based on image information measure and neutral network. Using these essential properties of step edges, which are directional and structural and whose gray level distribution in neighborhood, as a input vector to the BP neutral network we get the good result of proposed algorithm. And also we get the satisfactory experimental result using rose image and cell images an experimental and analysing image.

Edge Pattern Classification Method for Efficient Line Detection (효율적인 직선 검출을 위한 에지 패턴 분류 방법)

  • Park, Sang-Hyun;Kim, Jong-Ho;Kang, Eui-Sung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.10a
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    • pp.918-920
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    • 2011
  • In this paper, a simple edge pattern classification method is proposed for detecting straight line segments in an image corrupted by impulse noise. Corrupted images have complicated edge patterns. To detect straight line from an complicated edge pattern, it is needed to simplify the entire edge. The proposed algorithm separates the entire edge into 4 directional partial edge patterns. Each line segment is separated from the partial edge image where several line segments are overlapped, and then the straight line is detected. The results of the experiments emphasize that the proposed algorithm is simple but accurate.

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Effective Beam Width for Flat-Plate Systems Having Edge Beams under Lateral Loads (수평하중을 받는 테두리보가 있는 플랫플레이트 시스템의 유효보폭계수)

  • Han, Sang-Whan;Cho, Ja-Ock;Park, Young-Mi
    • Journal of the Korea Concrete Institute
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    • v.20 no.2
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    • pp.213-219
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    • 2008
  • The purpose of this study is to propose frame analysis method for flat plate slabs having edge beam under lateral loads. Flat plate system is defined as the system only with slab of uniform thickness and column. However, the slab system generally incorporate edge beams at exterior connection in actual design. ACI 318 (2005) allows three methods for conducting flat plate system analysis subjected to lateral loads. There are the finite element method (FEM), the equivalent frame method (EFM), and the effective beam width method (EBWM). Among methods, the EBWM enables us to analyze practically by substituting the actual slab to beam element. In this model, the beam element has a thickness equal to that of the slab, and effective beam width equal to some fraction of the slab transverse width. However, the established EBWM was generally proposed for variables of geometry or stiffness reduction factor and seldom proposed for the effect of edge beams. This study verifies that, in the case of flat plate system having edge beams at exterior connections, the lateral stiffness is considerably larger than without edge beams. Therefore it need to analysis method for considered the effect of edge beams. In this study, an analysis model is proposed for the flat plate system having edge beams under lateral loads by considering the effect of edge beams. To verify the accuracy of proposed model, this study compared results of the proposed EBWM with results of FEM of flat plate systems having edge beams under lateral loads. Also, the proposed approach is compared with experimental results of former research.

An interleaver to reduce the edge-effect in turbo codes with CRC (CRC를 사용한 터보부호에서 edge-effect를 감소시키기 위한 인터리버)

  • Lee, Byeong-Gil;Bae, Sang-Jae;Jeong, Geon-Hyeon;Ju, Eon-Gyeong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.39 no.4
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    • pp.165-172
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    • 2002
  • In the next generation mobile communications, powerful channel coding is essential in order to obtain high quality multimedia services. Turbo code can achieve good error performance by iterative decoding, but more iterations result in additional computational complexity and delay. Thus, a method to reduce the number of iterations without additional performance degradation is needed. Turbo code with CRC is known to be the most efficient method to reduce the number of iterations. In this scheme, the performance may be degraded by the edge-effect like the conventional turbo code without CRC. In this paper, a method to eliminate the edge-effect is proposed by adopting D-parameter to the conventional s-random interleaver. As results of simulation, the edge-effect of the turbo code with CRC is shown to be successfully eliminated by using the new interleaver designed with D-parameter.

Saptio-temporal Deinterlacing Based on Edge Direction and Spatio-temporal Brightness Variations (에지 방향성과 시공간 밝기 변화율을 고려한 시공간 De-Interlacing)

  • Jung, Jee-Hoon;Hong, Sung-Hoon
    • Journal of Broadcast Engineering
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    • v.16 no.5
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    • pp.873-882
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    • 2011
  • In this paper, we propose an efficient deinterlacing algorithm which interpolates the missing scan lines by weighted summing of the intra and the inter interpolation pixels according to the spatio-temporal variation. In the spatial interpolation, we adopt a new edge based spatial interpolation method which includes edge directional refinement. The conventional edge dependent interpolation algorithms are very sensitive to noise due to the failure of estimating edge direction. In order to exactly detect edge direction, our method first finds the edge directions around the pixel to be interpolated and then refines edge direction of the pixel using weighted maximun frequent filter. Futhermore, we improve the accuracy of motion detection by reducing the possibility of motion detection error using 3 tab median filter. In the final interpolation step, we adopt weighted sum of intra and inter interpolation pixels according to spatio-temporal variation ratio, thereby improving the quality in slow moving area. Simulation results show the efficacy of the proposed method with significant improvement over the previous methods in terms of the objective PSNR quality as well as the subjective image quality.

Content Based Image Retrieval Based on A Novel Image Block Technique Combining Color and Edge Features

  • Kwon, Goo-Rak;Haoming, Zou;Park, Sei-Seung
    • Journal of information and communication convergence engineering
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    • v.8 no.2
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    • pp.185-190
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    • 2010
  • In this paper we propose the CBIR algorithm which is based on a novel image block method that combined both color and edge feature. The main drawback of global histogram representation is dependent of the color without spatial or shape information, a new image block method that divided the image to 8 related blocks which contained more information of the image is utilized to extract image feature. Based on these 8 blocks, histogram equalization and edge detection techniques are also used for image retrieval. The experimental results show that the proposed image block method has better ability of characterizing the image contents than traditional block method and can perform the retrieval system efficiently.

Buckling of rectangular plates with mixed edge supports

  • Xiang, Y.;Su, G.H.
    • Structural Engineering and Mechanics
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    • v.14 no.4
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    • pp.401-416
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    • 2002
  • This paper presents a domain decomposition method for buckling analysis of rectangular Kirchhoff plates subjected to uniaxial inplane load and with mixed edge support conditions. A plate is decomposed into two rectangular subdomains along the change of the discontinuous support conditions. The automated Ritz method is employed to derive the governing eigenvalue equation for the plate system. Compatibility conditions are imposed for transverse displacement and slope along the interface of the two subdomains by modifying the Ritz trial functions. The resulting Ritz function ensures that the transverse displacement and slope are continuous along the entire interface of the two subdomains. The validity and accuracy of the proposed method are verified with convergence and comparison studies. Buckling results are presented for several selected rectangular plates with various combination of mixed edge support conditions.