• Journal of Advanced Marine Engineering and Technology
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• 제22권4호
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• pp.468-480
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• 1998

A flow measurement system which is able to measure the instantaneous three-dimensional velocity components and the pressure distribution of fluid flows is developed using a digital image processing system and the stereoscopic photogrammetry. This system consists of two TV cameras a digital image processor and a 32-bit microcomputer. The capability of the developed system is verified by a preliminary test in which three-dimensional displancements of moving particles arranged on a rotating plate are tracked automatically. The constructed system is through the measurement and spatial pressure distribution is also obtained. The measurement uncertainty of this system is evaluated quantitatively. The present technique is applicable to the measurement of an unsteady fluid phenomenon especially to the measurement of three-dimensional velocity field of a complex flow.

• 응용통계연구
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• 제30권3호
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• pp.345-362
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• 2017

자료 분석가가 대용량 데이터를 분석할 때 이해하기 쉽고 효과적으로 전달하기 위하여 다양한 데이터 시각화 방법들을 사용하고 있다. 그 중 3차원 그림은 2차원 화면상에서 입체로 표현하기 위하여 그림을 회전시켜야 한다. 이러한 단점을 보완하기 위하여 본 연구에서는 3차원 시각화 자료를 입체적으로 살펴보는 방법으로 가상현실을 이용한 두 가지 방식인 Batch method와 Real-time method를 제안하였다. 이 방법들을 통하여 3차원 시각화 자료를 입체적으로 살펴볼 때 3차원 구조를 좀 더 명확하게 확인할 수 있을 것이다.

• 한국정밀공학회지
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• 제23권2호
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• pp.181-190
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• 2006

In the industry, three-dimensional coloring has been needed for a realistic prototype. The Z-corporation developed a 3D printer which provides a three-dimensional colored prototype. However, the process cannot be adopted to models fabricated by other rapid prototyping processes. In addition, time and cost for manufacturing colored prototypes still remain to be improved. In this study, a new coloring process using an ink-jet head is proposed for color printing on a three-dimensional surface. Process parameters such as the angle and the distance between the ink-jet nozzle and the three-dimensional surface should be investigated through experiments. In order to minimize the distortion of a 2D image, the correction matrix according to the sloped angle is proposed and obtained by analysis of printing errors. An image on the doubly curved surface is printed so as to verify the proposed method. As a practical example, a helmet is chosen for printing images on the curved surface. The practical applicability of the correction matrix is then demonstrated by printing the character images on the surface of the helmet.

• Journal of information and communication convergence engineering
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• 제14권1호
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• pp.57-63
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• 2016

In generally, the resolution of reconstructed three-dimensional images can be seriously degraded by undesired occlusions in the integral imaging system, because the undesired information of the occlusion overlap the three-dimensional images to be reconstructed. To solve the problem of the undesired occlusion, we present an exemplar-based image restoration method in integral imaging system. In the proposed method, a minimum spanning tree-based stereo matching method is used to remove the region of undesired occlusions in each elemental image. After that, the removed occlusion region of each elemental images are re-established by using the exemplar-based image restoration method. For further improve the performance of the image restoration, the structure tensor is used to solve the filling error cause by discontinuous structures. Finally, the resolution enhanced three-dimensional images are reconstructed by using the restored elemental images. The preliminary experiments are presented to demonstrate the feasibility of the proposed method.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 춘계학술대회
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• pp.131-134
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• 1995

A three dimensional fractal coding with a perceptually enhanced matching is proposed. Since most of medical images (e.g. computed tomography or magnetic resonance image) have three dimensional character, the searching region is extended to adjacent slices. For perceptually enhanced matching, a high frequency booster filter is used for prefiltering of the original image, and the least mean square error matching is applied to this edge enhanced image rather than the original image. From the simulation with the magnetic resonance images ($255{\times}255$, 8bits/pixel). the proposed algorithm provides excellent image quality with compression rations higher than 10. Compared to existing fractal coding the algorithm also provides better subjective image quality with higher compression ratio.

• 치과방사선
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• 제23권2호
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• pp.335-344
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• 1993

The purpose of this study was to clarify the spatial relationship of temporomandibular joint and to an aid in the diagnosis of temporomandibular disorder. For this study, three-dimensional images of normal temporomandibular joints were reconstructed by computer image analysis system and three-dimensional reconstructive program integrated in computed tomography. The obtained results were as follows: 1. Two-dimensional computed tomograms had the better resolution than three dimensional computed tomograms in the evaluation of bone structure and the disk of TMJ. 2. Direct sagittal computed tomograms and coronal computed tomograms had the better resolution in the evaluation of the disk of TMJ. 3. The positional relationship of the disk could be visualized, but the configuration of the disk could not be clearly visualized on three-dimensional reconstructive CT images. 4. Three-dimensional reconstructive CT images had the smoother margin than three-dimensional images reconstructed by computer image analysis system, but the images of the latter had the better perspective. 5. Three-dimensional reconstructive images had the better spatial relationship of the TMJ articulation, and the joint spaces were more clearly visualized on dissection images.

• 한국의상디자인학회지
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• 제14권3호
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• pp.37-49
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• 2012

The purpose of this study is to provide basic data of dress design by researching three-dimensional decorative techniques representing flowers, a popular motif in dress design. This study analyzed 44 dresses that were presented in Valentino collection. The result of this study is as follows: First, the detailing expression method can show various patterns and colors through embroidery technique, sub-materials, and bonding techniques in embroidery, beads flower, and ribbon flowers. Second, the fabric flower technique expressed flower image in three-dimension in more various images than do either the ribbon or beads flower technique. Fabric flowers are mostly made from the same material as dresses. The expression technique of fabric flower is classified into the following three classifications: 1) A technique underlying a flower image with one, two and three large flowers, 2) a technique decorating a large area with a number of an identical motif, and 3) a technique highlighting a part of the body or design line by attracting eyes to one point, creating a corsage decorated where a designer wants to emphasize. Third, a silhouette technique realizes a flower image with a silhouette of a dress like sculpted structure and it is thus used less than a detailing expression technique. A flower image is expressed by making use of body lines or emphasizing the face. Finally, flower images on a dress were realized as a full blossomed flower, through visually streamlined shapes and curved lines.

• 스마트미디어저널
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• 제3권4호
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• pp.22-27
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• 2014

3차원 복원은 실세계에 존재하는 물체를 가상의 공간에 재건하고 자유로운 시점을 선택하여 물체를 관찰할 수 있게 한다. 이러한 3차원 복원 기술은 교육, 문화, 예술 등 분야를 막론하고 다양한 곳에서 사용되고 있다. 3차원 복원 시스템을 구현하기 위해 본 논문에서는 Microsoft사에서 출시된 Kinect를 이용하여 다시점 시스템을 구성해서 고품질의 3차원 객체를 복원하는 방법을 제안한다. 먼저 3대의 Kinect를 객체의 전면에 수렴형으로 설치하여 색상 영상과 깊이 영상을 획득한다. 그런데 원본의 깊이 영상은 깊이 값을 가지지 않는 부분이 존재한다. 따라서 본 논문에서는 이 부분을 적절한 깊이 값으로 채워 넣기 위해서 깊이 가중치를 추가한 결합형 양방향 필터를 적용한다. 또한 다시점 시스템에서 얻은 원본의 색상 영상은 서로 색상이 일치하지 않는 문제가 존재하는데 이를 그대로 이용하여 3차원 모델 정합을 하면 색상이 부자연스럽게 연결된 3차원 모델을 얻게 된다. 따라서 이러한 색상 불일치의 문제를 해결하기 위해서 본 논문에서는 다시점 시스템에서의 3차원 기하학적 정보를 이용한 색상 보정 방법을 사용한다. 실험을 통해 제안한 방법을 이용하여 획득한 3차원 모델이 원본 3차원 모델보다 색상과 형태 관점에서 자연스럽게 표현된 것을 확인할 수 있었다.

• Journal of International Society for Simulation Surgery
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• 제1권1호
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• pp.19-22
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• 2014

As computer technology develops and this is applied to medical image field, three dimensional image reconstruction technology using computer simulation is utilized in various categories that include anatomical study and biomechanics study of human body. Especially orthopedic surgeons are able to investigate biomechanical function and be provided information for operations with this technology in terms of ligament reconstruction of knee. And this technology can be utilized in preparing preoperative planning and instructions and training. This review is about three dimensional image reconstruction technology which is utilized in ligament reconstruction of knee.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2001년도 Proceedings of 2001 Korea-Japan Joint Seminar on Particle Image Velocimetry
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• pp.100-107
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• 2001

A simple new technique of particle depth position measurement, which can be applied for three-dimensional velocity measurement of fluid flows, is proposed. Two color illumination system that intensity is encoded as a function of z-coordinate is introduced. A calibration procedure is described and a profile of small sphere is detected by using the present method as preliminary test. Then, this method is applied to three-dimensional velocity field measurement of simple flow fields seeded with tracer particles. The motion of the particles is recorded by color 3CCD camera. The particle position in the image plane is read directly from the recorded image and the depth of each particle is measured by calculation of the intensity ratio of encoded two color illumination. Therefore three-dimensional velocity components are reconstructed. Although the result includes to some extent error, the feasibility of the present technique for three-dimensional velocity measurement was confirmed.