• Journal of Korean Society for Geospatial Information Science
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• v.6 no.1 s.11
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• pp.65-74
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• 1998

The acquisition and analysis system of accurate geometrical digital data is very important in side of maintaining the traditional culture for the preservation of cultural properties. This study is on the construction and shape analysis of precise digital data to manage more successfuly using the CRP method and 3D Mono Mobile System. Also this study could acquisite 3D geometrical digital data, make such various space analysis and section, projection, and calculation of bias, area and volume and modeling by rendering technique on the misterious bell of great king of SungDuck, one of the greatest bells in periods of TongIl Silla. So, We suggest utilization of image analysis method to safety diagnosis for the maintenance of cultural properties, archeological and artistic research.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.8
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• pp.418-425
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• 2005

3D surface reconstruction is to make the original geometry of 3D objects from 2D geometric information. Barequet's algorithm is well known and most widely used in surface reconstruction. It tiles matched regions first, then triangulates clefts using dynamic programming. However it takes considerably long processing time while manipulating complex model. Our method tiles a simple region that does not have branches along minimally distant vertex pairs at once. When there are branches, our method divides contour lines into a simple region and clefts. We propose a fast and simple method that calculates medial axes using a minimum distance in cleft region. Experimental results show that our method can produce accurate models than the previous method within short time.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.5
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• pp.1-11
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• 2020

Image-based virtual try-on (VTON) is becoming popular for online apparel shopping, mainly because of not requiring 3D information for try-on clothes and target humans. However, existing 2D algorithms, even when utilizing advanced non-rigid deformation algorithms, cannot handle large spatial transformations for complex target human poses. In this study, we propose a 3D clothing reconstruction method using a 3D human body model. The resulting 3D models of try-on clothes can be more easily deformed when applied to rest posed standard human models. Then, the poses and shapes of 3D clothing models can be transferred to the target human models estimated from 2D images. Finally, the deformed clothing models can be rendered and blended with target human representations. Experimental results with the VITON dataset used in the previous works show that the shapes of reconstructed clothing are significantly more natural, compared to the 2D image-based deformation results when human poses and shapes are estimated accurately.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.745-747
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• 2004

소실점은 실 공간의 평행한 직선들이 영상에서 만나는 점으로서 카메라 파라미터 추정. 영상을 사용한 3차원 구조복원 등에서 널리 사용되는 영상 상에 존재하는 3차원 기하에 대한 암묵적인 특징 정보이다. 본 논문에서는 영상으로부터 안정적으로 소실점을 검출하기 위한 새로운 방법을 제시한다. 먼저 단위구 상에서 셀 기반의 소실 공간을 EM 알고리즘의 초기 소실점으로 사용함한 신뢰성 있는 소실점 추출 방법을 제안한다. 또한 단일 영상에서 제거되지 않는 이상치에 대해 다중 영상에서 H응 직선이 가자는 사영불변치인 planar collineation과 harmonic range를 이용하여 보다 정확한 소실점을 구하기 위한 방법을 제안한다. 본 논문에서 제안한 알고리즘을 다양한 영상을 통해 실험한 결과 안정적이고 신뢰할만한 소실점 검출이 가능하였다.

• The Transactions of the Korea Information Processing Society
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• v.4 no.4
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• pp.1132-1140
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• 1997

In many vision tasks of the major obstacles is the specular highkight of smoth objects, which causes a misinterpretation of objects.This paper presents an dffcient algorithm for highight detection and object reconstruction, blsed on the theory of photometric stereo in which the location of highilight changes as the position of illumination source changes.Two images, referred to as base image and reference image.are sequentially taken with two different positionhs of the two images.The difference image is thresholded to detct the specular spike of the highlight.Then the specu-lar lobe around the specular spike is detected to reconstruct the object.The proposed algorithm can be applied to metals and dielectrics, regardlless of the surface chracteristics.This method can also be aplied to the case when the background is brighter than the object.

• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.387-394
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• 2004

In this paper, we propose a modified unsupervised linear alignment algorithm for building an aligned corpus. The original algorithm inserts null characters into both of two aligned strings (source string and target string), because the two strings are different from each other in length. This can cause some difficulties like the search space explosion for applications using the aligned corpus with null characters and no possibility of applying to several machine learning algorithms. To alleviate these difficulties, we modify the algorithm not to contain null characters in the aligned source strings. We have shown the usability of our approach by applying it to different areas such as Korean-English back-trans literation, English grapheme-phoneme conversion, and Korean morphological analysis.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10b
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• pp.559-561
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• 1999

구형 파노라믹 영상은 영상기반의 가상현실 시스템에서 가상환경을 구축하기 위해 널리 이용되고 있다. 이러한 구형 파노라믹 영상은 카메라를 회전시켜 실세계를 촬영하고 각 영상들을 정렬(image alignment)을 거쳐 구에 사상시킴으로써 얻어진다. 실세계로부터 직업 입력된 영상을 가상환경으로 표현하기 때문에 기하학적 기반의 가상환경에 비해 현실감이 뛰어나다. 그러나 고정된 시점에서 카메라의 회전에 대해서만 가상환경의 영상이 복원 가능하므로 가상환경의 항해(navigation)에 있어서 제약을 받는다. 본 논문에서는 시점의 이동 운동에 따른 운동시차(motion parallax)를 제공하기 위해 구 파노라믹 영상의 특정 부분에 TIP(Tour Into the Picture)기법을 이용하여 spidery mesh 인터페이스를 제공하는 방법을 제안한다. 본 논문에서 제안하는 가상환경 저작 기술은 보다 나은 사용자 상호 작용(interaction)을 제공하는 영상기반 가상 환경 구축에 활용될 수 있다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.4
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• pp.375-384
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• 2005

Three dimensional urban models are being increasingly applied for various purposes such as city planning, telecommunication cell planning, traffic analysis, environmental monitoring and disaster management. In recent years, technologies from CAD and GIS are being merged to find optimal solutions in three dimensional modeling of urban buildings. These solutions include modeling of the interior building space as well as its exterior shape visualization. Research and development effort in this area has been performed by scientists and engineers from Computer Graphics, CAD and GIS. Computer Graphics and CAD focussed on precise and efficient visualization, where as GIS emphasized on topology and spatial analysis. Complementary research effort is required for an effective model to serve both visualization and spatial analysis purposes. This study presents an efficient way of using the CAD plans included in the building register documents to reconstruct the internal space of buildings. Topological information was built in the geospatial database and merged with the geometric information of CAD plans. as well as other attributal data from the building register. The GIS network modeling method introduced in this study is expected to enable an effective 3 dimensional spatial analysis of building interior which is developing with increasing complexity and size.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.10
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• pp.491-498
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• 2001

We present a method of modeling lights from photographs taken with conventional imaging equipment. It does not use both any geometrical information and special apparatus to calculate surface reflection properties. To represent surface reflection properties of the scene, we use BRDFs which are calculated by radiance values of surface elements and light sources. And the BRDF data of each surface is further transformed to the spherical harmonic domain for efficient storage. Thus it allows to reconstruct the photo-realistic scene under different light sources, to manipulate diversely the arbitrary light source and to control exposure time of camera sensor. Moreover we test our algorithm with real image instead of synthetic image.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.667-670
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• 2007

볼륨 데이터에 대한 압축 기법의 필요성은 데이터 용량의 증가와 네트워크 사용량의 증가와 함께 더불어 증가해 왔다. 현재에는 다양한 압축 기법이 개발돼 있으며, 사용자는 데이터 유형이나 응용 분야에 맞춰 압축 기법을 선택, 적용할 수 있다. 그러나 최근에는 응용 과학자들로부터 생성되는 데이터의 용량이 기하급수적으로 증가했는데, 이렇게 응용과학 분야에서 생성되는 데이터는 대부분 3차원 볼륨 데이터다. 2차원 이미지나 3차원 동영상 데이터의 경우에는 다양한 표준 압축 방식을 사용할 수 있지만 3차원 볼륨 데이터에 적용할 수 있는 방법은 한정돼 있으며, 특히 시간가변(time-varying) 볼륨 데이터에 대한 압축 표준은 거의 존재하지 않는다고 볼 수 있다. 본 논문에서는 시간가변 볼륨 데이터에 대한 압축 방식을 제안한다. 이 방식은 가시화를 목적으로 하는 시간가변 볼륨 데이터의 인코딩을 목적으로 하며, MPEG의 I-프레임과 P-프레임 개념을 사용해서 압축률을 높인다. 본 방식은 시간가변 부동 소수점 데이터(single precision floating-point data)로 구성된 시간가변 볼륨 데이터를 대상으로 하는데, 한 블록 단위의 무작위 복원을 지원하며 Daubechies 웨이블릿 필터와 프레임간의 상관 관계를 사용, 대형 시간가변 볼륨 데이터를 이미지 화질을 보존한다.