• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.697-700
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• 1998

스테레오 영상으로부터 3차원 거리 정보를 추출하는 일은 수학적으로 불량 설정 문제(ill-posed problem)이다. 본 논문은 스테레오 정합을 정칙화(regularization)와 최소화(minimization) 문제로 설정하여 변이 (disparity)를 구한다. 최소화할 에너지 함수로 기울기 벡터(gradient vector)를 사용하여 촤우 카메라의 차이에 대응하고, 영상에 존재하는 깊이 불연속점(depth discontinuties)을 찾아내어 이를 보존하면서 정칙화를 실행하는 스테레오 정합 알고리즘을 제시한다. 다양한 스테레오 영상에 대한 실험 결과를 함께 나타내었다.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.129.1-129
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• 2001

In this paper, we present an approach for matching images from finding interesting points and applying new image interpolation algorithm. New algorithms are developed that automatically align the input images match them and reconstruct 3-D surfaces. The interpolation algorithm is designed to cope with simple shapes. The proposed image interpolation algorithm generate a rotation image about vertical axes by an any angle from 4 base images. Each base image that was obtained from CCD camera has an angle difference of 90$^{\circ}$ The proposed image interpolation algorithm use the geometric analysis of image and depth information.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.209-210
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• 2007

Obtained disparity map from the stereo camera by using the several stereo matching algorithms carries lots of noise because of various causes. In our approach, mode filtering and noise elimination technique using the histogram and projection-based region merging methods are adopted for improving the quality of disparity map and image segmentation. The proposed algorithms are implemented in VHDL and the real-time experimentation shows the accurately divided objects.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.9
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• pp.83-90
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• 2009

In this paper, a method for reduction of error ratio by external light noise is proposed, which separates error moving component caused by external light noise from moving component of an object, using depth information of stereo image. If measured depth information change of extracted moving component is insignificant, the moving component is considered as external light noise, which concludes that there is no moving object. Experimental results assert the usefulness of the proposed method which makes error ratios by external light noise and by false image as shadow diminish.

• Journal of Internet Computing and Services
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• v.11 no.1
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• pp.59-69
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• 2010

With the growing number of web services, there arise issues of finding suitable services. But, the traditional keyword search method is insufficient for two reasons: (1) this does not capture the underlying semantics of web services. (2) this does not suffice for accurately specifying users' information needs. In order to overcome limitations of this keyword search method, we propose a novel syntactic analysis and ontology learning method. The syntactic analysis method gives us a breadth of coverage for common terms, while the ontology learning method gives a depth of coverage by providing relationships. By combining these two methods, we hope to improve both the recall and the precision. We describe an experimental study on a collection of 508 web services that shows the high recall and precision of our method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.6A
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• pp.458-463
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• 2012

In this paper, we propose a direct depth map acquisition method for the convergence camera array as well as the parallel camera array. The conventional methods perform image rectification to reduce complexity and improve accuarcy. However, image rectification may lead to unwanted consequences for the convergence camera array. Thus, the proposed method excludes image rectification and directly extracts depth values using the epipolar constraint. In order to acquire a more accurate depth map, occlusion detection and handling processes are added. Reasonable depth values are assigned to the obtained occlusion region by the distance and color differences from neighboring pixels. Experimental results show that the proposed method has fewer limitations than the conventional methods and generates more accurate depth maps stably.

• Journal of Korea Multimedia Society
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• v.17 no.6
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• pp.733-740
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• 2014

With the development and spread of 3D display, users can easily experience an augmented reality with 3D features. Therefore, the demand for content of an augmented reality is exponentially growing in various fields. A traditional augmented reality environment was generally created by CG(Computer Graphics) modelling production tools. However, this method takes too much time and efforts to create an augmented environment. To create an augmented environment similar to the real world, everything in the real world should be measured, gone through modeling, and located in an augmented environment. But the time and efforts spent in the creation don't produce the same environment as the real world, making it hard for users to feel the sense of reality. In this study, multi-scale 3D panorama content augmented system is suggested by using a depth-map. By finding matching features from images to add 3D features to an augmented environment, a depth-map is derived and embodied as panorama, producing high-quality augmented content system with a sense of reality. With this study, limits of 2D panorama technologies will be overcome and a sense of reality and immersion will be provided to users with a natural navigation.

• Journal of Korea Multimedia Society
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• v.25 no.8
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• pp.1038-1048
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• 2022

Ultrasound is one of the effective methods for skin treatment. The skin penetration depth of the ultrasound depends on the ultrasonic frequency, that is, when the ultrasonic frequency is high, the depth is shallow. We have developed a transducer which can generate effectively 3 different ultrasonic frequencies removing interference between 3 types of frequencies according to impedance matching technology. The generated powers of transducer are 40.67W at 3.MHz, 17.46W at 11.7 MHz, and 14.79W at 21.5 MHz. The signal interference between the three frequencies is designed so that they do not interfere with each other by separating the signals using the SPDT (Single Pole, Double Throw) switch. The developed hybrid ultrasound transducer can be applied in skin care or skin treatment and beauty therapy.

• Smart Media Journal
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• v.2 no.4
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• pp.27-33
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• 2013

Multi-view video system provides both realistic 3D feelings and free-view navigation. But it is hard to transmit too huge data, so we send only two or three view images and generate intermediate view image using depth information. In this paper, we propose high quality multi-view image generation method from stereoscopic images. Since the stereo matching method does not provide accurate disparity values for all the pixels, especially at the occlusion area, we propose an occlusion handling method using the background pixels at first. We also apply a joint bilateral filtering to enhance the disparity map at the object boundary since it can affect the quality of synthesized images significantly. Finally, we can generate virtual view images at intermediate view positions using confidence map to reduce bad pixel and hole's error. Experimental results show the proposed method performs better than the conventional method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.12
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• pp.2146-2152
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• 2008

In In this paper, we proposed a new JPEG2000 codec using multiresolution-based rendering (MRBR) technique for video compression of 3-dimensional digital cinema. We introduced discrete wavelet transform (DWT) for stereoscopic image and stereo matching technique in the wavelet domain. The disparity was extracted using stereo matching and transmitted with the reference (left) image. Since the generated right image was degraded by the occlusion lesion, the residual image which is generated from difference between the original right image and the generated one was transmitted at the same tine. The disparity data was extracted using the dynamic programming method in the disparity domain. There is high correlation between the higher and lower subbands. Therefore we decreased the calculation amount and enhanced accuracy by restricting the search window and applying the disparity information generated from higher subband.