• Title/Summary/Keyword: 선분 복원

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Reconstruction of a 3D Model using the Midpoints of Line Segments in a Single Image (한 장의 영상으로부터 선분의 중점 정보를 이용한 3차원 모델의 재구성)

  • Park Young Sup;Ryoo Seung Taek;Cho Sung Dong;Yoon Kyung Hyun
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.4
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    • pp.168-176
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    • 2005
  • We propose a method for 3-dimensionally reconstructing an object using a line that includes the midpoint information from a single image. A pre-defined polygon is used as the primitive and the recovery is processed from a single image. The 3D reconstruction is processed by mapping the correspondence point of the primitive model onto the photo. In the recent work, the reconstructions of camera parameters or error minimizing methods through iterations were used for model-based 3D reconstruction. However, we proposed a method for the 3D reconstruction of primitive that consists of the segments and the center points of the segments for the reconstruction process. This method enables the reconstruction of the primitive model to be processed using only the focal length of various camera parameters during the segment reconstruction process.

3-D Primitive Reconstruction from Center Point of Line Segment (선분의 중점을 이용한 3차원 원시기하모델 복원)

  • 조성동;윤경현
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.04a
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    • pp.721-723
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    • 2002
  • 본 논문은 한 장의 사진으로부터 선분과 선분의 중점을 이용한 원시기하모델의 3차원 재구성 시스템을 제안한다. 이 시스템은 선분과 중점을 추출할 수 있는 미리 정의된 다면체를 원시기하모델로 사용하며 그 원시기하모델의 각 점을 사용자가 사진에 매핑 시키는 것으로서 3차원 재구성이 수행된다. 미리 정의된 원시기하모델의 사용은 사용자에게 기존의 소실점 입력 방식보다 직관적인 3차원 재구성을 가능하게 한다. 사진에 매핑된 원시기하모델이 포함하고 있는 2차원상의 선분과 선분의 중점으로부터 원시기하모델을 3차인 재구성한다.

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Image-based Modeling by Minimizing Projection Error of Primitive Edges (정형체의 투사 선분의 오차 최소화에 의한 영상기반 모델링)

  • Park Jong-Seung
    • The KIPS Transactions:PartB
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    • v.12B no.5 s.101
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    • pp.567-576
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    • 2005
  • This paper proposes an image-based modeling method which recovers 3D models using projected line segments in multiple images. Using the method, a user obtains accurate 3D model data via several steps of simple manual works. The embedded nonlinear minimization technique in the model parameter estimation stage is based on the distances between the user provided image line segments and the projected line segments of primitives. We define an error using a finite line segment and thus increase accuracy in the model parameter estimation. The error is defined as the sum of differences between the observed image line segments provided by the user and the predicted image line segments which are computed using the current model parameters and camera parameters. The method is robust in a sense that it recovers 3D structures even from partially occluded objects and it does not be seriously affected by small measurement errors in the reconstruction process. This paper also describesexperimental results from real images and difficulties and tricks that are found while implementing the image-based modeler.

Multiresolutional Reconstruction from Contours (윤곽선을 이용한 다중해상도적 복원)

  • 민경하;이인권
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.11
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    • pp.629-654
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    • 2003
  • A new multiresolutional scheme that reconstructs a polygonal mesh from the set of contours is presented. In the first step, we apply a radial gradient method to extract the contours on the sampled slices from a volume data. After classifying the types of the edges on the contours, we represent the contour using the context-free grammar. The polygons between two neighboring contours are generated through the traversal of the derivation trees of the context-free grammar. The polygonal surface of the coarsest resolution is refined through the refinement of the contours, which is executed by casting more rays on the slices. The topologies between the polygonal surfaces of various resolutions are maintained from the fact that the radial gradient method preserves the topologies of the contours of various resolutions. The proposed scheme provides efficient computation and compression methods for the tiling procedure with the feature preservation.

Coupled Line Cameras as a New Geometric Tool for Quadrilateral Reconstruction (사각형 복원을 위한 새로운 기하학적 도구로서의 선분 카메라 쌍)

  • Lee, Joo-Haeng
    • Korean Journal of Computational Design and Engineering
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    • v.20 no.4
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    • pp.357-366
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    • 2015
  • We review recent research results on coupled line cameras (CLC) as a new geometric tool to reconstruct a scene quadrilateral from image quadrilaterals. Coupled line cameras were first developed as a camera calibration tool based on geometric insight on the perspective projection of a scene rectangle to an image plane. Since CLC comprehensively describes the relevant projective structure in a single image with a set of simple algebraic equations, it is also useful as a geometric reconstruction tool, which is an important topic in 3D computer vision. In this paper we first introduce fundamentals of CLC with reals examples. Then, we cover the related works to optimize the initial solution, to extend for the general quadrilaterals, and to apply for cuboidal reconstruction.

3D Mesh Compression Based on Layer of Mesh and Operation Code (메쉬의 계층 및 연산코드 기반 3차원 메쉬 압축)

  • 이민정;권용무;김창헌
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10d
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    • pp.415-417
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    • 2002
  • 날로 커져가는 3D 모델을 효율적으로 사용하기 위한 노력으로 압축처리 방법들이 연구되고 있다. 본 논문에서는 3D 모델의 메쉬를 Layer로 분할하여 Vertex Layer와 Triangle Layer를 생성 후, 삼각형들을 몇가지 연산코드로 분류하여 압축(compression)하는 방법을 제안한다. Triangle Layer는 기본 정점으로부터 연결된 선분의 정점들로 이루어진 Vertex Layer의 쌍을 이용하여 만들어진다. 이 Triangle Layer에 해당 되는 삼각형들의 연결 정보를 제안한 연산코드로 분류하고, 이것을 엔트로피 코딩하여 3D 모델을 압축한다. 이 기법은 삼각형의 형태를 기준으로 한 개나 두 개의 삼각형을 하나의 연산코드로 분류하거나 삼각형의 연결 상황에 따라 하나의 연산코드로 분류하여 연결정보를 표현한다. 복원(decompression)시에는 연산 코드를 이용하여 삼각형의 연결정보를 뽑아내면 원 상태의 3D 모델을 획득할 수 있다. 이 방법은 연결 정보를 무손실 압축하는 방법으로, 지금까지 제안된 압축기법과 비교할 때, 간단하면서도 월등한 압축 효과를 볼 수 있다.

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2D LiDAR based 3D Pothole Detection System (2차원 라이다 기반 3차원 포트홀 검출 시스템)

  • Kim, Jeong-joo;Kang, Byung-ho;Choi, Su-il
    • Journal of Digital Contents Society
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    • v.18 no.5
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    • pp.989-994
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    • 2017
  • In this paper, we propose a pothole detection system using 2D LiDAR and a pothole detection algorithm. Conventional pothole detection methods can be divided into vibration-based method, 3D reconstruction method, and vision-based method. Proposed pothole detection system uses two inexpensive 2D LiDARs and improves pothole detection performance. Pothole detection algorithm is divided into preprocessing for noise reduction, clustering and line extraction for visualization, and gradient function for pothole decision. By using gradient of distance data function, we check the existence of a pothole and measure the depth and width of the pothole. The pothole detection system is developed using two LiDARs, and the 3D pothole detection performance is shown by detecting a pothole with moving LiDAR system.

High-resolution 3D Object Reconstruction using Multiple Cameras (다수의 카메라를 활용한 고해상도 3차원 객체 복원 시스템)

  • Hwang, Sung Soo;Yoo, Jisung;Kim, Hee-Dong;Kim, Sujung;Paeng, Kyunghyun;Kim, Seong Dae
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.10
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    • pp.150-161
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    • 2013
  • This paper presents a new system which produces high resolution 3D contents by capturing multiview images of an object using multiple cameras, and estimating geometric and texture information of the object from the captured images. Even though a variety of multiview image-based 3D reconstruction systems have been proposed, it was difficult to generate high resolution 3D contents because multiview image-based 3D reconstruction requires a large amount of memory and computation. In order to reduce computational complexity and memory size for 3D reconstruction, the proposed system predetermines the regions in input images where an object can exist to extract object boundaries fast. And for fast computation of a visual hull, the system represents silhouettes and 3D-2D projection/back-projection relations by chain codes and 1D homographies, respectively. The geometric data of the reconstructed object is compactly represented by a 3D segment-based data format which is called DoCube, and the 3D object is finally reconstructed after 3D mesh generation and texture mapping are performed. Experimental results show that the proposed system produces 3D object contents of $800{\times}800{\times}800$ resolution with a rate of 2.2 seconds per frame.

Optimization of Processing Conditions for the Production of Puffed Rice (팽화미 제조 공정조건의 최적화)

  • Cheon, Hee Soon;Cho, Won Il;Jhin, Changho;Back, Kyeong Hwan;Ryu, Kyung Heon;Lim, Su Youn;Chung, Myong Soo;Choi, Jun Bong;Lim, Taehwan;Hwang, Keum Taek
    • Culinary science and hospitality research
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    • v.21 no.1
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    • pp.77-89
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    • 2015
  • The objective of this study was to optimize processing conditions for the production of an instant puffed rice product using response surface methodology (RSM) and contour analysis. Sensory and texture qualities, and physical properties of the puffed rice were analyzed with various processing conditions related to drying and puffing temperature, and moisture content. Preference, color intensity, cohesiveness, rehydration ratio, density and lightness of the puffed rice product significantly varied depending on the processing conditions. The responses showed high $R^2$ values (0.623, 0.852, 0.735, 0.688, and 0.790) and lack-of-fit. Rehydration ratio was found to have a negative correlation with density in the condition of drying and puffing temperature. Lightness and preference scores of the puffed rice increased as the moisture content increased. According to RSM, the preference scores were very highly related to the moisture content, and the optimum processing conditions of the puffed rice product were at $40^{\circ}C$ of drying temperature, with 11.0% of moisture content, and at $232.7^{\circ}C$ of puffing temperature.