• Title/Summary/Keyword: edge-crossing

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Modified Watershed Algorithm Considering Zero-Crossing of Gradient (Gradient의 Zero-Crossing을 이용한 개선된 Watershed Algorithm)

  • Park, Dong-In;Ko, Yun-Ho;Park, Young-Woo
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.389-390
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    • 2007
  • In this paper, we propose a modified watershed algorithm to obtain exact edge of region. The proposed method adjusts priority at zero-crossing point of gradient in order to make the point of region decision time postponed. We compare the proposed method with a previous method and prove that this method can extract more correct edge of region.

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Modified Watershed Algorithm for Extracting Correct Edge and Reducing Processing Time (정확한 경계 추출 및 수행시간 단축을 위한 개선된 워터쉐드 알고리즘)

  • Park, Dong-In;Kim, Tae-Won;Ko, Yuh-Ho;Choi, Jae-Gark
    • Journal of Korea Multimedia Society
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    • v.13 no.10
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    • pp.1463-1473
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    • 2010
  • In this paper, we propose a modified watershed algorithm to extract more correct edge and reduce processing time. Two new algorithms are proposed in this paper. The first one is applying two conventional watershed expansion methods known as rainfall and immersion simulation jointly. We analyze the advantage and problem of each simulation and then propose a new expansion method that keeps the advantage and removes the problem in order to extract more correct edge and reduce processing time. The second is a new priority decision algorithm to obtain more correct edge of a region. Some zero-crossing points of gradient are expected to be edge of a region but the conventional method has a limitation that it cannot extract those points as edge. Therefore we propose a new priority decision algorithm for watershed in order to get more correct edge. We compare the proposed method with the conventional method through experiments and prove that the proposed method can extract more correct edge of region.

A Study on a New Locally Adaptive Edge Operator (신국부 적응 에지 연산자에 관한 연구)

  • 정규성;박래홍
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.24 no.5
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    • pp.841-848
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    • 1987
  • This paper presents a new two-stage edge detection algorithm which can give thin edges and can find edges between low contrast regions. In the first stage, the potential edge points are obtained using the proposed edge operator which is motivated by the concept of the E filter. And in the second stage, the real edge points adre detected by comparing the potential edge values with the lically adaptive threshold values of the corresponding potential edge points and by testing whether the potential edge points are zero-crossing points or not. It is shown quantitatively that the proposed algorithm can find edges effectively in an image with impulse noise, and also the results of applying the proposed algorithm to real images are presented.

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A Study on the Location of Bicycle Crossing considering Safety of Bicycle Users at Intersection (자전거 이용자의 안전성을 고려한 교차로 자전거 횡단도의 설치 위치에 관한 연구)

  • Hwang, Junghoon
    • International Journal of Highway Engineering
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    • v.16 no.1
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    • pp.91-98
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    • 2014
  • PURPOSES : Recently, there are increasing bicycle accidents along with increasing bicycles users. Bicycle accidents occurred frequently by perpendicular collision form at intersection inner. In order to improve safety of bicycle, drivers need to be aware of bicycles on the road and intersection geometric designs need to be designed to reduce risk associated with collisions between bicycles and car. This study aims to review the location of bicycle crossing in the viewpoint of bicycle safety. METHODS : Four types of bicycle crossing by curve radius and driver's check around the behavior are set to simulate the risk of collisions between bicycles and car turning right. Simulation using fortran programming are conducted on total 60 cases. RESULTS : Bicycle crossing located behind of crosswalk is lower the risk of collisions with car in all cases. In addition to the larger curve radius of pavement edge at intersection and the more pay attention to the rear by the turn head to the right is too low the risk of collisions with car. CONCLUSIONS : It is show that the location of bicycle crossing is safer behind than in front of crosswalk in the viewpoint of bicycle safety.

A Study on Efficient Watershed Algorithm by Using Improved SUSAN Algorithm

  • Choi, Yong-Hwan;Kim, Yong-Ho;Kim, Joong-Kyu
    • Proceedings of the Korea Multimedia Society Conference
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    • 2003.05b
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    • pp.431-434
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    • 2003
  • In this paper, we propose an efficient method not only f3r producing accurate region segmentation, solving the over-segmentation problem of watershed algorithm but also f3r reducing post-processing time by reducing computation loads. Through this proposed method, region segmentation of neighboring objects and discrimination of similar intensities were effectively obtained. Input image of watershed algorithm has used the derivative-based detectors such as Sobel and Canny. But proposed method uses the pixels-similarity-based detector, that is, SUSAN. By adopting this proposed method, we can reduce the noise problem and solve the problem of over-segmentation and not lose the edge information of objects. We also propose Zero-Crossing SUSAN. With Zero-Crossing SUSAN, the edge localization, times and computation loads can be improved over those obtained from existing SUSAN

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2.5D Metabolic Pathway Drawing based on 2-layered Layout (2-계층 레이아웃을 이용한 2.5차원 대사 경로 드로잉)

  • Song, Eun-Ha;Ham, Sung-Il;Lee, Sang-Ho;Park, Hyun-Seok
    • Journal of KIISE:Software and Applications
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    • v.36 no.11
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    • pp.875-890
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    • 2009
  • Metabolimics interprets an organism as a network of functional units and an organism is represented by a metabolic pathway i.e., well-displayed graph. So a software tool for drawing pathway is necessary to understand it comprehensively. These tools have a problem that edge-crossings exponentially increase as the number of nodes grows. To apply automatic graph layout techniques to the genome-scale metabolic flow, it is very important to reduce unnecessary edge-crossing on a metabolic pathway layout. In this paper, we design and implement 2.5D metabolic pathway layout modules. Metabolic pathways are represented hierarchically by making use of the '2-layered layout algorithm' in 3D. It enhances the readability and reduces unnecessary edge-crossings by using 3D layout modules instead of 2D layout algorithms.

Pruning Algorithm for Spokes Puzzle (수레바퀴 살 퍼즐에 관한 전정 알고리즘)

  • Sang-Un Lee
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.24 no.4
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    • pp.89-97
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    • 2024
  • The problem of the spokes puzzle(SP), which connects the spokes(edges) required by the wheel axis (hub, vertex) without intersection to form a network in which all the hubs are connected, can be said to be a wasteland of research. For this problem, there is no algorithm that presents a brute-force search or branch-and-bound method that takes exponential time. This paper proposes an algorithm to plot a lattice graph with cross-diagonal lines of m×n for a given SP and to pruning(delete) the surplus edges(spokes). The proposed algorithm is a simple way to select an edge of a hub whose number of edges matches the hub requirement and delete the edge crossing it. If there is no hub with an edge that meets the hub requirement, a strategy was adopted to preferentially delete(pruning) the edge of the hub with the maximum amount of spare. As a result of applying the proposed algorithm to 20 benchmarking experimental data, it was shown that a solution that minimizes the number of trials and errors can be obtained for all problems.

Stability Evaluation of Bump Crossing and Loading of Proto-type Mini-Forwarder by Computer Simulation (컴퓨터 시뮬레이션을 이용한 소형 임내차 시작기의 장애물 통과 및 적재 안정성 평가)

  • Park H. K.;Kim K. U.;Shim S. B.;Kim J. W.;Park M. S.;Song T. Y.
    • Journal of Biosystems Engineering
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    • v.30 no.6 s.113
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    • pp.366-372
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    • 2005
  • The objective of this study was to evaluate the bump crossing and loading stability of a proto-type mini-forwarder under development. The evaluation was performed by computer simulation using a multi-body dynamic analysis program, Recur- Dyn 5.21. The proto-type was modeled and its properties such as mass, mass center, and mass moment of inertia were determined using 3D CAD modeler, Solid Edge 8.0. The $\%$ errors of masses, mass center, mass moment of inertia, and vertical motion of the model were within less than $10\%$ and the model's behavior agreed relatively well with those of the proto-type when traversing over a rectangular bump. Using the validated model, bump crossing of the proto-type was simulated and the loading limit was determined. It was found that effects of the shapes of bump on the bump crossing performance was insignificant within the practical heights of bumps. Stability of bump crossing increased with loading. However, loading of longer logs than 2.7 m made the crossing unstable because the ends of logs contacted ground when traversing over the bump. The maximum loading capacity of the proto-type was estimated to be 7.8 kN of 2.7 m long logs.

Edge Detection Using Mean Difference within a Connected Bimodal Region (이분된 지역평균의 차를 이용한 경계점 검출법)

  • Jung, Moon-Jo;Shim, Young-Serk;Hwang, Chan-Sik
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1360-1363
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    • 1987
  • Two edge detection methods are devised and tested. First one makes use of mean-difference between two connected regions after bimodal thresholding within a local window. It appears experimentally to provide reduced edge width maintaining good connectivity. It seems due to the use of the threshold obtained from a larger neighborhood. Second one uses additionally the gradient information to detect approximate zero crossing points of second directional derivative. This provides edges thinned nearly to one pixel width.

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Segmentation of Measured Point Data for Reverse Engineering (역공학을 위한 측정점의 영역화)

  • 양민양;이응기
    • Korean Journal of Computational Design and Engineering
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    • v.4 no.3
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    • pp.173-179
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    • 1999
  • In reverse engineering, when a shape containing multi-patched surfaces is digitized, the boundaries of these surfaces should be detected. The objective of this paper is to introduce a computationally efficient segmentation technique for extracting edges, ad partitioning the 3D measuring point data based on the location of the boundaries. The procedure begins with the identification of the edge points. An automatic edge-based approach is developed on the basis of local geometry. A parametric quadric surface approximation method is used to estimate the local surface curvature properties. the least-square approximation scheme minimizes the sum of the squares of the actual euclidean distance between the neighborhood data points and the parametric quadric surface. The surface curvatures and the principal directions are computed from the locally approximated surfaces. Edge points are identified as the curvature extremes, and zero-crossing, which are found from the estimated surface curvatures. After edge points are identified, edge-neighborhood chain-coding algorithm is used for forming boundary curves. The original point set is then broke down into subsets, which meet along the boundaries, by scan line algorithm. All point data are applied to each boundary loops to partition the points to different regions. Experimental results are presented to verify the developed method.

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