• Title/Summary/Keyword: Polygon-based Vertex Selection

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Semi-automatic Field Morphing : Polygon-based Vertex Selection and Adaptive Control Line Mapping

  • Kwak, No-Yoon
    • International Journal of Contents
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    • v.3 no.4
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    • pp.15-21
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    • 2007
  • Image morphing deals with the metamorphosis of one image into another. The field morphing depends on the manual work for most of the process, where a user has to designate the control lines. It takes time and requires skills to have fine quality results. It is an object of this paper to propose a method capable of realizing the semi-automation of field morphing using adaptive vertex correspondence based on image segmentation. The adaptive vertex correspondence process efficiently generates a pair of control lines by adaptively selecting reference partial contours based on the number of vertices that are included in the partial contour of the source morphing object and in the partial contour of the destination morphing object, in the pair of the partial contour designated by external control points through user input. The proposed method generates visually fluid morphs and warps with an easy-to-use interface. According to the proposed method, a user can shorten the time to set control lines and even an unskilled user can obtain natural morphing results as he or she designates a small number of external control points.

Vertex Selection method using curvature information (곡률 정보를 이용한 정점 선택 기법)

  • 윤병주;이시웅;강현수;김성대
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.505-508
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    • 2003
  • The current paper proposes a new vertex selection scheme for polygon-based contour ceding. To efficiently characterize the shape of an object, we incorporate the curvature information in addition to the conventional maximum distance criterion in vertex selection process. The proposed method consists of “two-step procedure.” At first, contour pixels of high curvature value are selected as key vertices based on the curvature scale space (CSS), thereby dividing an overall contour into several contour-segments. Each segment is considered as an open contour whose end points are two consecutive key vertices and is processed independently. In the second step, vertices for each contour segment are selected using progressive vertex selection (PVS) method in order to obtain minimum number of vertices under the given maximum distance criterion ( $D_{MAX}$). Experimental results are presented to compare the approximation performances of the proposed and conventional methods.s.

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An Efficient Polygonal Approximation Method in the Rate-Distorion Sense (비트량-왜곡을 고려한 효율적인 다각형 근사화 기법)

  • 윤병주;고윤호;김성대
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.1
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    • pp.114-123
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    • 2003
  • This paper proposes an efficient method for encoding the shape information of the object in the image. The polygonal approximation method is categorized into a loss coding method and is widely used for approximating object's shape information. The proposed method selects less number of vertices than IRM (iterated refinement method) or PVS (progressive vertex selection) when the maximum distortion is given, so reduces the bit-rates. The proposed method selects the vertices of a polygon with a simple and efficient method considering the rate-distortion sense. We construct the shape information coder, which shows the outstanding performance in the rate-distortion sense, based on the conventional progressive vertex selection method and the new vertex selection condition that we propose in this paper. Simulation results show that the proposed method has better performance than other conventional vertex selection methods in the tate-distortion sense.

A Two-Step Vertex Selection Method for Minimizing Polygonal Approximation Error (다각형 근사 오차를 최소화하기 위한 2단계 정점 선택 기법)

  • 윤병주;이훈철;고윤호;이시웅;김성대
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.6
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    • pp.114-123
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    • 2003
  • The current paper proposes a new vertex selection scheme for polygon-based contour coding. To efficiently characterize the shape of an object, we incorporate the curvature information in addition to the conventional maximum distance criterion in vertex selection process. The proposed method consists of "two-step procedure." At first, contour pixels of high curvature value are selected as key vortices based on the curvature scale space (CSS), thereby dividing an overall contour into several contour-segments. Each segment is considered as an open contour whose end points are two consecutive key vortices and is processed independently. In the second step, vertices for each contour segment are selected using progressive vertex selection (PVS) method in order to obtain minimum number of vertices under the given maximum distance criterion ( $D_{max}$$^{*}$). Furthermore, the obtained vortices are adjusted using the dynamic programming (DP) technique to optimal positions in the error area sense. Experimental results are presented to compare the approximation performances of the proposed and conventional methods.imation performances of the proposed and conventional methods.

Vertex selection method considering texture degradation for contour approximation (밝기 왜곡을 고려한 윤곽선 근사화용 정점 선택 방법)

  • Choi Jae Gark;Lee Si-Woong;Koh Chang-Rim;Lee Jong-Keuk
    • Journal of Broadcast Engineering
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    • v.10 no.4 s.29
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    • pp.632-642
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    • 2005
  • This paper presents a new vertex selection scheme for the polygon-based contour approximation. In the proposed method, the entire contour is partitioned into partial segments and they are approximated adaptively with variable accuracy. The approximation accuracy of each segment is controlled based on its relative significance. By computing the relative significance with the texture degradation in the approximation error region, the visual quality enhancement in the reconstructed frames can be achieved under the same amount of the contour data. For this purpose, a decision rule for $d_{max}$ is derived based on inter-region contrasts. In addition, an adaptive vertex selection method using the derived rule is proposed. Experimental results are presented to show the superiority of the proposed method over conventional methods.

Inter-frame vertex selection algorithm for lossy coding of shapes in video sequences (동영상에서의 모양 정보 부호화를 위한 정점 선택 알고리즘)

  • Suh, Jong-Yeul;Kim, Kyong-Joong;Kang, Moon-Gi
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.37 no.4
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    • pp.35-45
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    • 2000
  • The vertex-based boundary encoding scheme is widely used in object-based video coding area and computer graphics due to its scalability with natural looking approximation. Existing single framebased vertex encoding algorithm is not efficient for temporally correlated video sequences because it does not remove temporal redundancy. In the proposed method, a vertex point is selected from not only the boundary points of the current frame but also the vertex points of the previous frame to remove temporal redundancy of shape information in video sequences. The problem of selecting optimal vertex points is modeled as finding shortest path in the directed acyclic graph with weight The boundary is approximated by a polygon which can be encoded with the smallest number of bits for maximum distortion. The temporal redundancy between two successive frames is efficiently removed with the proposed scheme, resulting in lower bit-rate than the conventional algorithms.

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