• Title/Summary/Keyword: projective frame

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Projective Reconstruction Method for 3D modeling from Un-calibrated Image Sequence (비교정 영상 시퀀스로부터 3차원 모델링을 위한 프로젝티브 재구성 방법)

  • Hong Hyun-Ki;Jung Yoon-Yong;Hwang Yong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.2 s.302
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    • pp.113-120
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    • 2005
  • 3D reconstruction of a scene structure from un-calibrated image sequences has been long one of the central problems in computer vision. For 3D reconstruction in Euclidean space, projective reconstruction, which is classified into the merging method and the factorization, is needed as a preceding step. By calculating all camera projection matrices and structures at the same time, the factorization method suffers less from dia and error accumulation than the merging. However, the factorization is hard to analyze precisely long sequences because it is based on the assumption that all correspondences must remain in all views from the first frame to the last. This paper presents a new projective reconstruction method for recovery of 3D structure over long sequences. We break a full sequence into sub-sequences based on a quantitative measure considering the number of matching points between frames, the homography error, and the distribution of matching points on the frame. All of the projective reconstructions of sub-sequences are registered into the same coordinate frame for a complete description of the scene. no experimental results showed that the proposed method can recover more precise 3D structure than the merging method.

A Study on Projective Reconstruction based on Factorization Method (분해법기반 프로젝티브 재구성에 관한 연구)

  • 정윤용;조청운;홍현기
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.191-194
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    • 2003
  • The recovery of 3D scene structure from multiple views has been long one of the central problems in computer vision. This paper presents a new projective reconstruction method based on factorization for un-calibrated image sequences. The proposed algorithm provides an effective measure to construct frame groups by using various information between frames. The experimental results show that the proposed method can reconstruct a more precise 3D structure than the precious methods such as the merging method.

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3D Motion of Objects in an Image Using Vanishing Points (소실점을 이용한 2차원 영상의 물체 변환)

  • 김대원;이동훈;정순기
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.11
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    • pp.621-628
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    • 2003
  • This paper addresses a method of enabling objects in an image to have apparent 3D motion. Many researchers have solved this issue by reconstructing 3D model from several images using image-based modeling techniques, or building a cube-modeled scene from camera calibration using vanishing points. This paper, however, presents the possibility of image-based motion without exact 3D information of scene geometry and camera calibration. The proposed system considers the image plane as a projective plane with respect to a view point and models a 2D frame of a projected 3D object using only lines and points. And a modeled frame refers to its vanishing points as local coordinates when it is transformed.

De Morgan Frames (드 모르간 틀)

  • 이승온
    • Journal for History of Mathematics
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    • v.17 no.2
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    • pp.73-84
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    • 2004
  • Stone introduced extremally disconnected spaces as the image of complete Boolean algebras under his famous duality between Bool and ZComp and they turn out to be projective objects in various categories of Hausdorff spaces and completely regular ones are exactly those X with Dedekind complete C(X, ). In the pointfree setting, extremally disconnected frame (= De Morgan frame) are those with De Morgan condition. In this paper, we investigate a historical aspect of De Morgan frame together with that of De Morgan.

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ON GENERALIZED QUASI-CONFORMAL N(k, μ)-MANIFOLDS

  • Baishya, Kanak Kanti;Chowdhury, Partha Roy
    • Communications of the Korean Mathematical Society
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    • v.31 no.1
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    • pp.163-176
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    • 2016
  • The object of the present paper is to introduce a new curvature tensor, named generalized quasi-conformal curvature tensor which bridges conformal curvature tensor, concircular curvature tensor, projective curvature tensor and conharmonic curvature tensor. Flatness and symmetric properties of generalized quasi-conformal curvature tensor are studied in the frame of (k, ${\mu}$)-contact metric manifolds.

A study on the calibration parameter estimation of camera using square calibration frame (정방형 교정 frame을 이용한 카메라의 교정 파라메타 추정에 관한 연구)

  • 최성구;노도환
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.7
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    • pp.127-137
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    • 1996
  • The 3-dimensional measurement using stereo vision system must achieve a camera calibration. So far, the 3-dimensional calibration technique that uses two-dimensional grid papar and a non-linear least square method has been developed and tested. But, this method is inefficient because it has many calculation procedure and a non-linear analysis. Therefore, this paper proposed the projective geometric method which produced the calibration parameter by vanishing point. The vanishing point is producted by a cross ratio and a parallel line pairs. The results of the computer simulation show utility of the proposed method.

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Video-based Height Measurements of Multiple Moving Objects

  • Jiang, Mingxin;Wang, Hongyu;Qiu, Tianshuang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.9
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    • pp.3196-3210
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    • 2014
  • This paper presents a novel video metrology approach based on robust tracking. From videos acquired by an uncalibrated stationary camera, the foreground likelihood map is obtained by using the Codebook background modeling algorithm, and the multiple moving objects are tracked by a combined tracking algorithm. Then, we compute vanishing line of the ground plane and the vertical vanishing point of the scene, and extract the head feature points and the feet feature points in each frame of video sequences. Finally, we apply a single view mensuration algorithm to each of the frames to obtain height measurements and fuse the multi-frame measurements using RANSAC algorithm. Compared with other popular methods, our proposed algorithm does not require calibrating the camera, and can track the multiple moving objects when occlusion occurs. Therefore, it reduces the complexity of calculation and improves the accuracy of measurement simultaneously. The experimental results demonstrate that our method is effective and robust to occlusion.

Mosaic Technique on Panning Video Images using Interpolation Search (보간 검색을 이용한 Panning 비디오 영상에서의 모자이크 기법)

  • Jang, Sung-Gab;Kim, Jae-Shin
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.5 s.305
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    • pp.63-72
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    • 2005
  • This paper proposes a new method to construct a panorama image from video sequences captured by the video camcoder revolving on the center axis of the tripod. The proposed method is consisted of two algorithms; frame selection and image mosaics. In order to select frames to construct the panorama image, we employ the interpolation search using the information in overlapped areas. This method can search suitable frames quickly. We construct an image mosaic using the projective transform induced from four pairs of quasi-features. The conventional methods select feature points by using only texture information, but the presented method in this paper uses the position of each feature point as well. We make an experiment on the proposed method with real video sequences. The results show that the proposed method is better than the conventional one in terms of image quality.

Graph-Based framework for Global Registration (그래프에 기반한 전역적 정합 방법)

  • 김현우;홍기상
    • Proceedings of the IEEK Conference
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    • 2000.09a
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    • pp.671-674
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    • 2000
  • In this paper, we present a robust global registration algorithm for multi-frame image mosaics. When we perform a pair-wise registration recovering a projective transformation between two consecutive frames, severe mis-registration among multiple frames, which are not consecutive, can be detected. It is because the concatenation of those pair-wise transformations leads to global alignment errors. To overcome those mis-registrations, we propose a new algorithm using multiple frames for constructing image mosaics. We use a graph to represent the temporal and spatial connectivity and show that global registration can be obtained through the search for an optimal path in the constructed graph. The definition of an adequate objective function characterizing the global registration provides a direct manipulation of the graph. In the presence of moving objects, especially large ones compared with low texture backgrounds, by using the likelihood ratio as the objective function, we can deal with some of the most challenging videos like basketball or soccer Moreover, the algorithm can be parallelized so it can be more efficiently implemented. Finally, we give some experimental results from real videos.

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