• Title/Summary/Keyword: Projective Method

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ITERATIVE FACTORIZATION APPROACH TO PROJECTIVE RECONSTRUCTION FROM UNCALIBRATED IMAGES WITH OCCLUSIONS

  • Shibusawa, Eijiro;Mitsuhashi, Wataru
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.737-741
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    • 2009
  • This paper addresses the factorization method to estimate the projective structure of a scene from feature (points) correspondences over images with occlusions. We propose both a column and a row space approaches to estimate the depth parameter using the subspace constraints. The projective depth parameters are estimated by maximizing projection onto the subspace based either on the Joint Projection matrix (JPM) or on the the Joint Structure matrix (JSM). We perform the maximization over significant observation and employ Tardif's Camera Basis Constraints (CBC) method for the matrix factorization, thus the missing data problem can be overcome. The depth estimation and the matrix factorization alternate until convergence is reached. Result of Experiments on both real and synthetic image sequences has confirmed the effectiveness of our proposed method.

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사영기하학의 성립과 그 기초 - 카를 크리스티안 폰 슈타우트(Karl Christian von Staudt, 1798-1867)의 이론을 중심으로

  • 한경혜
    • Journal for History of Mathematics
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    • v.15 no.1
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    • pp.1-14
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    • 2002
  • This paper treats the history of the fundament of projective geometry Especially we introduce the essence of the framework of Karl Chirstian von Staudt's ‘Geometrie der Lage’. Von Staudt used axiomatical method to bum the system of the projective geometry, and proved the fundamental theorem of projective geometry. And he handled imaginary elements (or the first time in synthetic projective geometry.

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Specification and Implementation of Projective Texturing Node in X3D

  • Kim, In-Kwon;Jang, Ho-Wook;Yoo, Kwan-Hee;Ha, Jong-Sung
    • International Journal of Contents
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    • v.12 no.2
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    • pp.1-5
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    • 2016
  • Extensible 3D (X3D) is the ISO standard for defining 3D interactive web- and broadcast-based 3D content integrated with multimedia. With the advent of this integration of interactive 3D graphics into the web, users can easily produce 3D scenes within web contents. Even though there are diverse texture nodes in X3D, projective textures are not provided. We enable X3D to provide SingularProjectiveTexture and MultiProjectiveTexture nodes by materializing independent nodes of projector nodes for a singular projector and multi-projector. Our approach takes the creation of an independent projective texture node instead of Kamburelis's method, which requires inconvenient and duplicated specifications of two nodes, ImageTexture and Texture Coordinate.

ON STUDY OF f-APPROXIMATION PROBLEMS AND σ-INVOLUTORY VARIATIONAL INEQUALITY PROBLEMS

  • Mitra, Siddharth;Das, Prasanta Kumar
    • Nonlinear Functional Analysis and Applications
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    • v.27 no.2
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    • pp.223-232
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    • 2022
  • The purpose of the paper is to define f-projection operator to develop the f-projection method. The existence of a variational inequality problem is studied using fixed point theorem which establishes the existence of f-projection method. The concept of ρ-projective operator and σ-involutory operator are defined with suitable examples. The relation in between ρ-projective operator and σ-involutory operator are shown. The concept of σ-involutory variational inequality problem is defined and its existence theorem is also established.

Validation of a Dwelling Depression Scale Based on Analysis of Projective Images (투사이미지 분석기반 고령자 주거우울 척도 타당화 연구)

  • Lee, Yewon;Park, Chongwook;Woo, Sungju
    • The Journal of the Convergence on Culture Technology
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    • v.4 no.2
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    • pp.1-7
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    • 2018
  • As the living environment is regarded as a key factor that affects the quality of life of the elderly, the necessity for an accurate measurement of depression for the elderly has increased. In order to diagnose accurately, it is crucial to consider variables such as the cognitive characteristics and living conditions. In this study, 301 persons over 65 years old who live in single and couple elderly households over 65 years were surveyed from 1 January 2018 to 2 February to measure the dwelling depression by applying projective images. The correlations between the dwelling depression and projective images are clarified and the reliability of the questionnaire was evaluated. The correlations between the geriatric dwelling depression index(GDDI) and the GDDI based on projective images(GDDI-I) are clarified. The accuracy of the GDDI-I is analyzed. As a result the projective image questionnaire has a correlation with the existing self-report questionnaire. It is hoped that the results will provide a basis for further researches on psychological diagnoses using the projective method.

Note on the estimation of informative predictor subspace and projective-resampling informative predictor subspace (다변량회귀에서 정보적 설명 변수 공간의 추정과 투영-재표본 정보적 설명 변수 공간 추정의 고찰)

  • Yoo, Jae Keun
    • The Korean Journal of Applied Statistics
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    • v.35 no.5
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    • pp.657-666
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    • 2022
  • An informative predictor subspace is useful to estimate the central subspace, when conditions required in usual suffcient dimension reduction methods fail. Recently, for multivariate regression, Ko and Yoo (2022) newly defined a projective-resampling informative predictor subspace, instead of the informative predictor subspace, by the adopting projective-resampling method (Li et al. 2008). The new space is contained in the informative predictor subspace but contains the central subspace. In this paper, a method directly to estimate the informative predictor subspace is proposed, and it is compapred with the method by Ko and Yoo (2022) through theoretical aspects and numerical studies. The numerical studies confirm that the Ko-Yoo method is better in the estimation of the central subspace than the proposed method and is more efficient in sense that the former has less variation in the estimation.

TIGHT ASYMMETRIC ORTHOGONAL ARRAYS OF STRENGTH 2 USING FINITE PROJECTIVE GEOMETRY

  • Aggarwal M.L.;Deng Lih Yuan;Mazumder Mukta D.
    • Journal of the Korean Statistical Society
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    • v.35 no.1
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    • pp.49-61
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    • 2006
  • Wu et al. (1992) constructed some general classes of tight asymmetric orthogonal arrays of strength 2 using the method of grouping. Rains et al. (2002) obtained asymmetric orthogonal arrays of strength 2 using the concept of mixed spread in finite projective geometry. In this paper, we obtain some new tight asymmetric orthogonal arrays of strength 2 using the concept of mixed partition in finite projective geometry.

3D reconstruction method without projective distortion from un-calibrated images (비교정 영상으로부터 왜곡을 제거한 3 차원 재구성방법)

  • Kim, Hyung-Ryul;Kim, Ho-Cul;Oh, Jang-Suk;Ku, Ja-Min;Kim, Min-Gi
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.391-394
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    • 2005
  • In this paper, we present an approach that is able to reconstruct 3 dimensional metric models from un-calibrated images acquired by a freely moved camera system. If nothing is known of the calibration of either camera, nor the arrangement of one camera which respect to the other, then the projective reconstruction will have projective distortion which expressed by an arbitrary projective transformation. The distortion on the reconstruction is removed from projection to metric through self-calibration. The self-calibration requires no information about the camera matrices, or information about the scene geometry. Self-calibration is the process of determining internal camera parameters directly from multiply un-calibrated images. Self-calibration avoids the onerous task of calibrating cameras which needs to use special calibration objects. The root of the method is setting a uniquely fixed conic(absolute quadric) in 3D space. And it can make possible to figure out some way from the images. Once absolute quadric is identified, the metric geometry can be computed. We compared reconstruction image from calibrated images with the result by self-calibration method.

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Simplified projective transform for reconstruction of cylindrical panorama (실린더 파노라마 영상의 재구성을 위한 단순화된 사영 변환)

  • Lee Kang-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.2 s.40
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    • pp.169-175
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    • 2006
  • In this paper we propose a method of reconstruction of cylindrical panorama using simplified projective transform from the panning image on the fixed camera. For the practical construction of cylindrical panorama we consider the rotation of the camera on the Y-axis only, even though considering the rotation components on all of the X,Y,Z axis on three-dimensional space for projective transform between general panoramas. The restriction mentioned above simplifies projective transform with existing 8 degrees of freedom into the one with 4 degrees of freedom. In the results, overall computation for projective transform can be decreased to the great extents in quantify, because the number of corresponding points required for inducing the transforming formula is gone down by half. Proposed algorithm from the simulation carried out in this paper shows similar performance and decreased computational quantity compared with existing algorithm. Also, it shows the construction of cylindrical panorama using simplified projective transform.

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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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