• 전자공학회논문지 IE
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• v.43 no.4
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• pp.105-114
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• 2006

In this paper, 3D input and output systems for a web-based real-time 3D video communication system using IEEE 1394 digital cameras, Intel Xeon Server system and Microsoft Directshow library is proposed. And some conditions for optimizing the operations of the stereo camera, 3D display and signal processing system are analyzed. Input & output systems are carefully selected, which can satisfy the required optimization conditions and the final 3D video communication system is implemented by using three optimized devices. The overall control system is developed with Microsoft Visual C++.Net and Microsoft DirectX 9.1 SDK. Some experimental results show that the observer can feel the natural presence from multi-view(4-view) 3D video of server system in real-time and also can feel the natural presence from 3D video of client system and finally suggest an application possibility of the proposed web-based real-time 3D video communication in real fields.

• The Journal of the Acoustical Society of Korea
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• v.28 no.4
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• pp.370-374
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• 2009

In this paper, we presents a new cone beam computerized tomography (CB CT) system for the reconstruction of 3 dimensional dynamic images. The system using cone beam has less the exposure of radioactivity than fan beam, relatively. In the system, the reconstruction 3-D image is reconstructed with the radiation angle of X-ray in the image processing unit and transmitted to the monitor. And in the image processing unit, the Three Pass Shear Matrices, a kind of Rotation-based method, is applied to reconstruct 3D image because it has less transcendental functions than the one-pass shear matrix to decrease a time of calculations for the reconstruction 3-D image in the processor. The new system is able to get 3~5 3-D images a second, reconstruct the 3-D dynamic images in real time.

• The Journal of the Acoustical Society of Korea
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• v.28 no.2
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• pp.141-147
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• 2009

This paper presents a new fast algorithm, rotation-based method (RBM), for the reconstruction of 3 dimensional image for cone beam computerized tomography (CB CT) system. The system used cone beam has less exposure time of radioactivity than fan beam. The Three-Pass Shear Matrices (TPSM) is applied, that has less transcendental functions than the one-pass shear method to decrease a time of calculations in the computer. To evaluate the quality of the 3-D images and the time for the reconstruction of the 3-D images, another 3-D images were reconstructed by the radon transform under the same condition. For the quality of the 3-D images, the images by radon transform was shown little good quality than REM. But for the time for the reconstruction of the 3-D images REM algorithm was 35 times faster than radon transform. This algorithm offered $4{\sim}5$ frames a second. It meant that it will be possible to reconstruct the 3-D dynamic images in real time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.10C
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• pp.982-989
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• 2007

In this paper, we propose a 3DTV system that considers user's view point and display environment. The proposed system consists of 3 parts - multi-view encoder/decoder, face-tracker, and 2D/3D converter. The proposed system try to encode multi-view sequence and decode it in accordance with the user's view point and it also gives a stereopsis to the multi-view image by using of 2D/3D conversion which converts decoded two-dimensional(2D) image to three-dimensional(3D) image. Experimental results shows that we are able to correctly reconstruct a stereoscopic view that is exactly corresponding to user's view point.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.6
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• pp.123-128
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• 2020

In this paper, we presents a new cone beam computerized tomography (CBCT) system for the reconstruction of 3 dimensional dynamic images. The system using cone beam has less the exposure of radioactivity than fan beam, relatively. In the system, the reconstruction 3-D image is reconstructed with the radiation angle of X-ray in the image processing unit and transmitted to the monitor. And in the image processing unit, the Three Pass Shear Matrices, a kind of Rotation-based method, is applied to reconstruct 3D image because it has less transcendental functions than the one-pass shear matrix to decrease a time of calculations for the reconstruction 3-D image in the processor. The new system is able to get 3~5 3-D images a second, reconstruct the 3-D dynamic images in real time. And we showed the Rotation-based method was good rather than existing reconstruction technique for 3D images, also found weakness and a solution for it.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.11b
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• pp.15-20
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• 1999

본 논문에서는 사람의 정면 얼굴을 찍은 컬러 동영상에서 얼굴의 각 구성 요소에 대한 특징점들을 추출하여 3차원 개인 얼굴 모델을 생성하고 이를 얼굴의 표정 움직임에 따라 애니메이션 하는 방법을 제시한다. 제안된 방법은 얼굴의 정면만을 촬영하도록 고안된 헬멧형 카메라( Head-mounted camera)를 사용하여 얻은 2차원 동영상의 첫 프레임(frame)으로부터 얼굴의 특징점들을 추출하고 이들과 3차원 일반 얼굴 모델을 바탕으로 3차원 얼굴 특징점들의 좌표를 산출한다. 표정의 변화는 초기 영상의 특징점 위치와 이 후 영상들에서의 특징점 위치의 차이를 기반으로 알아낼 수 있다. 추출된 특징점 및 얼굴 움직임은 보다 다양한 응용 이 가능하도록 최근 1단계 표준이 마무리된 MPEG-4 SNHC의 FDP(Facial Definition Parameters)와FAP(Facial Animation Parameters)의 형식으로 표현되며 이를 이용하여 개인 얼굴 모델 및 애니메이션을 수행하였다. 제안된 방법은 단일 카메라로부터 촬영되는 영상을 기반으로 이루어지는 MPEG-4 기반 화상 통신이나 화상 회의 시스템 등에 유용하게 사용될 수 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.62-62
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• 2018

무선영상취득시스템(WIA 시스템, Wireless Image Acquisition System)은 라즈베리 파이에 전용 카메라와 WiFi 모듈을 장착하여, 하천의 영상을 실시간으로 촬영하여 무선으로 서버로 전송하는 시스템이다. 이 시스템이 갖는 가장 큰 이점은 시스템을 구성하는 비용이 매우 저렴하다는 점이다. 라즈베리 본체와 카메라 모듈, WiFi 모듈 모두 매우 저렴하고, 또 사용하는 전력이 작아서 상용 전원이 아닌 태양광 발전이나 배터리 등을 이용할 수 있다. 따라서 비용과 장소에 구애받지 않고 손쉽게 어디든지 설치하여 하천의 상시 감시나 계측에 활용할 수 있다. 또한, 상용 전원을 이용하지 않아도 되기 때문에, 산간벽지나 오지 등의 소하천 관리에도 적합하다. 본 연구에서는 이 WIA 시스템을 경상남도 김해시의 대청천에 적용하여 홍수 시 하천의 수표면을 촬영하고, 촬영된 동영상을 분석하여 수위와 유속을 동시에 계측하여 유량을 산정하였다. 라즈베리 파이에 $640{\times}480$ 화소의 카메라를 장착하여 10분 간격으로 10초간의 동영상을 촬영하고, 이를 WiFi 모듈을 이용하여 무선으로 서버로 전송한다. 전송된 동영상을 분석하기 전에 설치 지점의 3차원 좌표 변환 자료와 횡단면 좌표를 입력하여 대상 지점의 측정 매개변수를 설정한다. 즉, 이들 자료에서 영상 내의 표정점과 측정선을 설정해 둔다. 그 다음, 전송된 동영상을 시공간 영상으로 만들어 수위를 분석한다. 비슷한 방법으로 동영상에서 유속을 분석하고, 분석된 수위와 유속, 그리고 미리 설정된 횡단면 좌표를 이용하여 유량을 산정해 낸다. 설치된 WIA 시스템을 실제로 운용하여, 2017년 9월 11일의 06:10~19:00의 호우 사상 전체를 분석하였다. 10분 간격으로 촬영된 10초간 동영상 중에서 적절한 분석이 가능한 영상 77개에서 수위와 유속을 분석한 결과, 최대 수위는 0.746 m(간이수위표 기준), 최대 유속은 0.962 m/s, 최대 유량은 $12.977m^3/s$에 이르렀다. 지점 특성상 다른 유속계를 이용한 검증은 사실상 불가능하였다. 또, 하폭이 넓어서 일출 전과 일몰 후의 촬영 자료는 분석이 어려운 점이 있다. 이러한 기술적 문제들을 보완하면, WIA 시스템을 이용한 소하천의 수위와 유속 측정 시스템은 경제성이고 효율이 높은 관측시스템으로 유망할 것으로 기대된다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.1
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• pp.33-42
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• 2001

Recently, the interests in the 3D image, generated from the range data and CAD, have exceedingly increased, accordingly a various 3D image database is being constructed. The efficient and fast scheme to access the desired image data is the important issue in the application area of the Internet and digital library. However, it is difficult to manage the 3D image database because of its huge size. Therefore, a proper descriptor is necessary to manage the data efficiently, including the content-based search. In this paper, the proposed shape descriptor is based on the voxelization of the 3D image. The medial axis transform, stemming from the mathematical morphology, is performed on the voxelized 3D image and the graph, which is composed of node and edge, is generated from skeletons. The generated graph is adequate to the novel shape descriptor due to no loss of geometric information and the similarity of the insight of the human. Therefore the proposed shape descriptor would be useful for the recognition of 3D object, compression, and content-based search.

• The Journal of the Korea Contents Association
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• v.9 no.7
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• pp.159-170
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• 2009

It is very important to extract the expression data and capture a face image from a video for online-based 3D face animation. In recently, there are many researches on vision-based approach that captures the expression of an actor in a video and applies them to 3D face model. In this paper, we propose an automatic data extraction system, which extracts and traces a face and expression data from realtime video inputs. The procedures of our system consist of three steps: face detection, face feature extraction, and face tracing. In face detection, we detect skin pixels using YCbCr skin color model and verifies the face area using Haar-based classifier. We use the brightness and color information for extracting the eyes and lips data related facial expression. We extract 10 feature points from eyes and lips area considering FAP defined in MPEG-4. Then, we trace the displacement of the extracted features from continuous frames using color probabilistic distribution model. The experiments showed that our system could trace the expression data to about 8fps.

• Journal of Digital Contents Society
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• v.17 no.1
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• pp.23-31
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• 2016

This study aims to develop a stereoscopic image authoring tool to effectively produce e-Book content that enhances user's sense of immersion in 3D environments. The proposed authoring tool consists of three core systems; 3D object editing, stereoscopic image, and image media production systems. First, the object editing system arranges and produces diverse objects that constitute virtual 3D spaces to fit the purpose of the content. In this case, commercial graphic authoring tools are utilized to design efficient data structures that can include produced external models. In addition, the material and textures of objects are made to be revisable and editable into the form wanted by the user. Thereafter, a stereoscopic image system will be implemented to produce the generated virtual scenes into stereoscopic images. This study uses the Anaglyph method so that the user can implement and use stereoscopic image scenes more easily. This method include functions to change the color of stereo cameras and control depth scaling. Finally, an image media production system will be implemented that will enable producing the produced stereoscopic images into single images or videos so that they can be effectively utilized in e-Book content.