• The Journal of the Korea Contents Association
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• v.17 no.3
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• pp.329-336
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• 2017

In video compression, Motion Estimation(ME) limits the performance of image quality and generated bit rates. However, it requires much complexity in the encoder part. Multi-view video uses many cameras at different positions. Multi-view video coding needs huge computational complexity in proportion to the number of the cameras. To reduce computational complexity and maintain the image quality, an effective motion estimation method is proposed in this paper. The proposed method exploiting the characteristics of motion vector distribution and the motion of video. The proposed is a kind of a hierarchical search strategy. This strategy consists of multi-grid rhombus pattern, diagonal pattern, rectangle pattern, and refinement pattern. Experiment results show that the complexity reduction of the proposed method over TZ search method and PBS (Pel Block Search) on JMVC (Joint Multiview Video Coding) can be up to 40~75% and 98% respectively while maintaining similar video image quality and generated bit rates.

• Korean Journal of Heritage: History & Science
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• v.47 no.1
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• pp.164-179
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• 2014

The Buddhas of the Three Words in a form of arranging Bhaiṣajyaguru and $Amit{\bar{a}}bha$ at its side based on ${\acute{S}}{\bar{a}}kyamuni$ at the center is enshrined in Daeungbojeon Hall of Daeheungsa Temple located at Haenam. So far, this Buddhas of the Three Words has been known as a wooden Buddha statue. However, as a result of X-ray screening, in left/right Buddha statues excepting main Buddha, wood and molding clay layer were observed at the same time. Therefore, this study intended to observe its internal structure, grafting method and to clarify making technique of Buddha statue during Joseon era based on image information being obtained through X-ray screening of The Buddhas of the Three Words of Daeheungsa Temple. As its result, it was revealed that form of ${\acute{S}}{\bar{a}}kyamuni$ was completed by mainly grafting 5 pieces of timber and this statue shows a typical wood grafted Buddha statue during Joseon era. Form of Bhaiṣajyaguru and $Amit{\bar{a}}bha$ were completed based on molding technique by applying clay on sculpture similar to its appearance after sculpturing more than 10 pieces of timber through its grafting. In other words, internal timber is considered to play a role of its core and grafting method of timber is more close to a technique of molding Buddha statue than to that of wooden Buddha statue during Joseon era. However, clay was directly applied on timber thinly, not applying clay thickly on it after winding straw rope on wooden core and its characteristic is that its facial area was completely composed of wooden construction only. Therefore, it is hard to rule out a possibility that the original sculpturing intention of an artist might be a wooden Buddha statue but in view of the fact that a word, 'molding' was used in a record of relics buried in statue, it could be seen that this Buddha statue might have been recognized as a molding statue at the time when creation of this statue was completed. It is considered that number of case of making statue based on this technique would be more increased when more results of X-ray screening should be accumulated and if more data should be collected, it would provide a significant evidence for identifying chronological, regional aspects of making technique of Buddha statue.

• Journal of Korea Multimedia Society
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• v.17 no.3
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• pp.333-341
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• 2014

Multi-view video is obtained by capturing one three-dimensional scene with many cameras at different positions. Multi-view video coding requires high computational complexity. To reduce computational complexity and maintain the image quality, an effective early termination motion estimation method is proposed in this paper. The proposed method exploiting the characteristic of motion vector distribution uses a hierarchical search strategy. This strategy method consists of multi-grid square search pattern, modified diamond search pattern, small diamond search pattern and raster search pattern. Experiment results show that the speedup improvement of the proposed method over TZ search method and FS(Full Search) method JMVC (Joint Multiview Video Coding) can be up to 1.7~4.5 times and 90 times faster respectively while maintaining similar video quality and bit rates.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.11a
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• pp.191-194
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• 2009

본 논문에서는 효율적인 다시점 비디오 부호화를 위해 히스토그램(histogram)을 이용한 다시점 비디오의 휘도(luminance)와 색차(chrominance)성분 보상 기법을 제안한다. 다시점 비디오는 카메라의 기하학적인 위치 차이와 여러 대의 카메라가 동일한 특성을 가지도록 완벽히 조정되지 못함으로 인해 동일한 시간대에 촬영된 인접한 시점 영상 간에 휘도와 색상의 차이가 발생할 수 있다. 이러한 특성은 인접한 카메라로부터 획득된 영상을 참조하여 시점간 움직임 예측 시에 오정합의 원인이 되어 부호화 효율을 떨어뜨리게 된다. 본 논문에서는 효율적인 다시점 비디오 부호화를 위해 시점간의 히스토그램을 비교하여 정합하는 휘도 및 색차 보상 기법을 수행한다. 일정한 시간 대역(time interval)에서 다시점 비디오의 평균 누적 히스토그램을 이용하여 참조 영상을 생성하고 각 시점별로 정합 함수를 통해 다시점 영상 간의 휘도와 색상의 불일치성을 보상한다. 제안하는 조명 보상 기법을 통하여 다시점 비디오 부호화 효율을 높일 수 있었다.

• Journal of Game and Entertainment
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• v.2 no.1
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• pp.35-44
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• 2006

Objective of this study is to develop a 3D car navigation system that shows the driving direction to a destination through real-time 3-D panoramic views of the route. For the purpose, a new searching process was established to find the optimal driving direction based on the driver's current location and the real-time traffic situation and the TIP (tour into the picture) method was extended to implement a wide virtual environment. A virtual environment was built up by applying the extended TIP method to the panoramic images taken at a constant distance from a real road, and then, displayed 3-D navigation as clear as the real images. The car navigation system developed in this study provides the optimal driving direction and real-time traffic situation using 2-D navigation module and 3D navigation module.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.6
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• pp.1383-1388
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• 2013

Even though a dual lens stereoscopic camera allows for convenient stereoscopic photography, the necessity for the research comes up, since the dual lens stereoscopic camera can cause visual discomfort during zoom-in due to the fixed convergence point. We propose a method based on which a convergence point can be adjusted to prevent visual discomfort during zoom-in for a dual lens stereoscopic camera. First, the relational model is classified into nine kinds and defined, depending on locations of focus, object, and convergence point. And then, the method to minimize visual discomfort is suggested by adjusting convergence point on the given model. We also implement the suggested methods with anaglyph computer graphic and demonstrate the superiority of them.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.5
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• pp.191-199
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• 1993

Investigation is given to the detailed procedure of a computer assisted automatic technique for ortho-image generation from digital stereo image data of close-range photographs scanned by the CCD camera scanner. After rectification of geometric scanning errors, the bundle adjustment technique was used to determine the exterior orientation parameters of terrestrial camera. An automatic correlation matching technique was applied to search for the conjugate pixels in digital stereo pairs. And the 3-dimensional coordinates of the corresponding pixels were calculated by the space intersection method. For the generation of ortho-image from the calculated coordinates and right image data values, inverse-weighted-distance average method was used. And the accuracy of the resulting ortho-image was checked by comparing its image coordinates with there corresponding ground coordinates for the check points.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.456-459
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• 2013

Even though a dual lens stereoscopic camera allows for convenient stereoscopic photography, the necessity for the research comes up, since the dual lens stereoscopic camera can cause visual discomfort during zoom-in due to the fixed convergence point. We propose a method based on which a convergence point can be adjusted to prevent visual discomfort during zoom-in for a dual lens stereoscopic camera. First, the relational model is classified into nine kinds and defined, depending on locations of focus, object, and convergence point. And then, the method to minimize visual discomfort is suggested by adjusting convergence point on the given model. We also implement the suggested methods with anaglyph computer graphic and demonstrate the superiority of them.

• Journal of Biomedical Engineering Research
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• v.25 no.2
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• pp.103-109
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• 2004

A virtual arthroscopy is a simulation of optical arthroscopy that reconstructs anatomical structures from tomographic images in joint region such as a knee, a shoulder and a wrist. In this paper, we propose a virtual arthroscopy based on isosurface raycasting, which is a kind of volume rendering methods for generating 3D images within a short time. Our method exploits a spatial data structure called min-max map to produce high-quality images in near real-time. Also we devise a physically-based camera control model using potential field. So a virtual camera can fly through in articular cavity without restriction. Using the high-speed rendering method and realistic camera control model, we developed a virtual arthroscopy system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.427-429
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• 2017

본 논문에서는 실시간으로 주행 중인 차량의 영상을 대상으로 ROI 영역을 추출하고 추출된 ROI 영역에 Warping 기법과 RANSAC 알고리즘을 적용하여 곡선 차선을 검출하는 방법을 제안한다. 제안된 방법은 실시간 영상에서 관심 영역을 ROI 영역으로 설정하고 영상의 원근감을 제거하기 위하여 Warping을 적용한다. Warping이 적용된 영상에서 차선의 밝기는 도로의 밝기보다 높다는 특징을 이용하여 노란색과 흰색 차선의 영역을 추출한다. 추출된 차선의 영역에서 곡선을 검출하기 위하여 RANSAC 알고리즘을 적용하여 곡선을 검출하기 위한 기준점을 설정한 후, 스플라인 기법을 적용하여 곡선을 검출한다. 실시간적으로 주행 중인 차량에서 촬영한 동영상을 대상으로 실험한 결과, 곡선 차선이 효과적으로 검출되었다. 따라서 제안된 방법이 자율 주행에 효율적으로 적용될 수 있는 가능성을 확인하였다.