• Journal of Advanced Marine Engineering and Technology
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• v.22 no.4
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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.

• The Korean Journal of Applied Statistics
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• v.30 no.3
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• pp.345-362
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• 2017

Various data visualization methods are utilized to analyze a huge amount of data. Among various methods, a three-dimensional image requires the rotation of the image to show a stereo image on a two-dimensional screen. This study discusses two methods of batch method and real-time method, which make it possible to construct of stereo images to improve the restriction of the three-dimensional image display with virtual reality. This investigation can be useful to better explore a three-dimensional data structure.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.2 s.179
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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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• v.14 no.1
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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.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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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.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.2
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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.

• Journal of the Korea Fashion and Costume Design Association
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• v.14 no.3
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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.

• Smart Media Journal
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• v.3 no.4
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• pp.22-27
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• 2014

Three-dimensional image reconstruction allows us to represent real objects in the virtual space and observe the objects at arbitrary view points. This technique can be used in various application areas such as education, culture, and art. In this paper, we propose an implementation method of the high-quality three-dimensional object using multiple Kinect cameras released from Microsoft. First, We acquire color and depth images from triple Kinect cameras; Kinect cameras are placed in front of the object as a convergence form. Because original depth image includes some areas where have no depth values, we employ joint bilateral filter to refine these areas. In addition to the depth image problem, there is an color mismatch problem in color images of multiview system. In order to solve it, we exploit an color correction method using three-dimensional geometry. Through the experimental results, we found that three-dimensional object which is used the proposed method is more naturally represented than the original three-dimensional object in terms of the color and shape.

• Journal of International Society for Simulation Surgery
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• v.1 no.1
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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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• 2001.12a
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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.