• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권7호
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• pp.3284-3306
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• 2018

This study proposes a method to develop an authoring system(GeoMaTree) for diverse trees that constitute a virtual landscape. The GeoMaTree system enables the simple, intuitive production of an efficient structure, and supports real-time processing. The core of the proposed system is a procedural modeling based on a mathematical model and an application that supports digital content creation on diverse platforms. The procedural modeling allows users to control the complex pattern of branch propagation through an intuitive process. The application is a multi-resolution 3D model that supports appropriate optimization for a tree structure. The application and a compatible function, with commercial tools for supporting the creation of realistic synthetic images and virtual landscapes, are implemented, and the proposed system is applied to a variety of 3D image content.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2921-2923
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• 2005

This paper presents to generate 3D building model using estimation of rooftop surface after 3D line segment extraction using hybrid stereo matching techniques in terms of the co-operation of area-based stereo and feature-based stereo. we first performed a junction extraction from 3D line segment data which was obtained by stereo images, and finally generated building's reliable rooftop surface model using LSE(Least Square Error) method after creating surfaces by grouped and fixed junction points. we generated synthetic images for experimentation by photo-realistic simulation on Avenches data set of Ascona aerial images.

• 한국컴퓨터정보학회논문지
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• 제9권4호
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• pp.109-116
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• 2004

본 논문은 여러 옷감 조각들을 이용하여 가상의 3차원 인체 모델에 옷을 입히기 위한 의복 시뮬레이션 시스템을 제안한다. 본 논문에서 의복은 서로 꿰매지는 2차원 재단 패턴으로 구성된다. 제안된 시스템은 3차원 인체 모델 파일과 2차원 재단 패턴 파일을 읽어 들인 다음에 질량-스프링 모델에 기반한 물리적 시뮬레이션에 의해 의복을 착용한 3D모델을 생성한다. 본 논문의 시스템은 사실적인 시뮬레이션을 위하여 인체 모델을 구성하는 삼각형과 의복을 구성하는 삼각형 사이의 충돌을 검사하고 반응 처리를 수행하였다. 인체를 구성하는 삼각형의 수가 매우 많으므로, 이러한 충돌 검사 및 반응 처리는 많은 시간을 필요로 한다. 이 문제를 해결하기 위하여, 본 논문에서는 공간 분할 기법을 이용하여 충돌 검사 및 반응 처리 수를 줄이는 방법을 제안한다. 실험 결과에 의하면 본 논문의 시스템은 사실적인 영상을 생성할 수 있었고 수초 이내에 가상 인체 모델에 의복을 입힐 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1055-1058
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• 2003

The robustness and reliability of vision algorithms is the key issue in robotic research and industrial applications. In this paper robust real time visual tracking in complex scene is considered. A common approach to increase robustness of a tracking system is the use of different model (CAD model etc.) known a priori. Also fusion or multiple features facilitates robust detection and tracking of objects in scenes of realistic complexity. Voting-based fusion of cues is adapted. In voting. a very simple or no model is used for fusion. The approach for this algorithm is tested in a 3D Cartesian robot which tracks a toy vehicle moving along 3D rail, and the Kalman filter is used to estimate the motion parameters. namely the system state vector of moving object with unknown dynamics. Experimental results show that fusion of cues and motion estimation in a tracking system has a robust performance.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권5호
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• pp.226-232
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• 2001

The ability to efficiently and robustly recover accurate 3D terrain models from sets of stereoscopic images is important to many civilian and military applications. To develop an effective and practical terrain modeling system, we propose a new multi-image stereo method which detect unreliable elevations in DEM(Digital Elevation Map), and fuse several DEMs from multiple sources into an accurate and reliable results. This paper focuses on two key factors for generating robust 3D terrain models: the ability to detect unreliable elevation estimates and the ability to fuse the reliable elevations into a single optimal terrain model. We apply the self-consistency methodology to reconstruct accurate DEM from multi-image and show the method is more effective than the conventional stereo image 3D reconstruction method. Using photo-realistic simulator, four synthetic image are generated from ground truth DEM and orthoimage to evaluate the accuracy of the proposed method quantitatively.

• ETRI Journal
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• 제35권6호
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• pp.969-979
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• 2013

Various simulation applications for hair, clothing, and makeup of a 3D avatar can provide more useful information to users before they select a hairstyle, clothes, or cosmetics. To enhance their reality, the shapes, textures, and colors of the avatars should be similar to those found in the real world. For a more realistic 3D avatar color reproduction, this paper proposes a spectrum-based color reproduction algorithm and color management process with respect to the implementation of the algorithm. First, a makeup color reproduction model is estimated by analyzing the measured spectral reflectance of the skin samples before and after applying the makeup. To implement the model for a makeup simulation system, the color management process controls all color information of the 3D facial avatar during the 3D scanning, modeling, and rendering stages. During 3D scanning with a multi-camera system, spectrum-based camera calibration and characterization are performed to estimate the spectrum data. During the virtual makeup process, the spectrum data of the 3D facial avatar is modified based on the makeup color reproduction model. Finally, during 3D rendering, the estimated spectrum is converted into RGB data through gamut mapping and display characterization.

• ETRI Journal
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• 제25권2호
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• pp.140-143
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• 2003

In this paper, we present a probabilistic approach to determining whether extracted facial features from a video sequence are appropriate for creating a 3D face model. In our approach, the distance between two feature points selected from the MPEG-4 facial object is defined as a random variable for each node of a probability network. To avoid generating an unnatural or non-realistic 3D face model, automatically extracted 2D facial features from a video sequence are fed into the proposed probabilistic network before a corresponding 3D face model is built. Simulation results show that the proposed probabilistic network can be used as a quality control agent to verify the correctness of extracted facial features.

• 한국전자통신학회논문지
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• 제6권6호
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• pp.831-838
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• 2011

컴퓨터 그래픽스 적용분야에서 표현되는 모습들은 현실 세계의 모습을 기반으로 컴퓨터 비전(Computer Vision) 분야에서는 사실적인 3D(Dimension) 모델 또는 가상 환경을 구축하기 위한 연구가 활발하게 진행되고 있다. 3D 디스플레이의 발전과 보급으로 인해 사용자들이 입체감 있는 3차원 가상현실을 손쉽게 접할 수 있게 됨에 따라 가상현실 콘텐츠에 대한 수요가 증가되고 있다. 본 논문은 소실점 위치에 따른 깊이지도 생성 기법을 이용하여 3D 파노라마 시스템을 제안했다. 3D 파노라마는 사용자에게 마치 촬영 장소에 서서 주위를 살펴보는 것과 같은 입체감 있는 효과가 나타난다. 또한, 3D 파노라마 시스템은 넓은 영역에 대해 근거리의 사물과 원거리의 배경에 대한 자유로운 시점과 변함없는 고화질의 사진과 같은 현실감 있는 3차원 입체영상이 제공된다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.536-539
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• 1999

In this paper we propose a 3D emotional expression method using a comic model for effective sign-language communications. Until now we have investigated to produce more realistic facial and emotional expression. When representing only emotional expression, however, a comic expression could be better than the real picture of a face. The comic face is a comic-style expression model in which almost components except the necessary parts like eyebrows, eyes, nose and mouth are discarded. We represent emotional expression using Action Units(AU) of Facial Action Coding System(FACS). Experimental results show a possibility that the proposed method could be used efficiently for sign-language image communications.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.452-455
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• 2007

3D stereoscopic viewing of large scale imagery, such as aerial photography and satellite images, needs different parallaxes relative to the display scale. For example, when a viewer sees a stereoscopic image of aerial photography, the optimal parallax of its zoom-in image should be smaller than that of its zoom-out. Therefore, relative parallax adjustment according to the display scale is required. Merely adjusting the spacing between stereo images is not appropriate because the depths of the whole image are either exaggerated or reduced entirely. This paper focuses on the improving stereoscopic viewing with a single remote sensing image and a digital surface model (DSM). We present the parallax adjustment technique to maximize the 3D realistic effect and the visual comfort. For remote sensing data, DSM height value can be regarded as disparity. There are two possible kinds of methods to adjust the relative parallax with a single image performance. One is the DSM compression technique: the other is an adjustment of the distance between the original image and its stereo-mate. In our approach, we carried out a test to evaluate the optimal distance between a single remote sensing image and its stereo-mate, relative to the viewing scale. Several synthetic stereo-mates according to certain viewing scale were created using a parallel projection model and their anaglyphs were estimated visually. The occlusion of the synthetic stereo-mate was restored by the inpainting method using the fields of experts (FoE) model. With the experiments using QuickBird imagery, we could obtain stereoscopic images with optimized parallax at varied display scales.