• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.220-221
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• 2011

본 논문에서는 스마트폰의 카메라와 플래시를 이용한 능동적 3차원 형상 취득 시스템을 제시한다. 두 대의 스마트폰을 이용하여 한 대의 스마트폰은 광원 역할과 광원 위치 추정을 위한 영상 취득을 하고 다른 스마트폰으로 고정된 위치에서 광원의 위치 변화에 따른 영상을 취득을 한다. 각 스마트폰에서 취득된 영상을 마커 기반에서 광원의 위치를 추정하고 카메라의 반응 함수에 의한 비선형적 왜곡과 렌즈의 왜곡을 보정한다. 광원의 방향 벡터와 보정된 영상의 밝기 값을 이용하여 photometric stereo 기법으로 3차원 형상을 취득한다.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.2
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• pp.67-72
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• 2020

AR service using the client-server method and existing physical markers(eg, OR Codes, etc.) causes a delay in the playback time of the contents because the contents download is executed after the marker recognition. In the case of the one-time installation method rather than the client-server method, proactive download of high-capacity contents for playback may cause an inefficiency of the storage space of the device(eg, smartphone, etc.). Therefore, in AR contents playback based on beacon's RSSI to secure the efficiency of the playback device storage space and to quickly play AR contents. The technique for high-speed playback in this study can be applied to various fields such as MICE exhibition using beacon signal.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3B
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• pp.339-348
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• 2004

Packet classification is an important factor to support various services such as QoS guarantee and VPN for users in Internet. Packet classification is a searching process for best matching rule on rule tables by employing multi-field such as source address, protocol, and port number as well as destination address in If header. In this paper, we propose hardware based packet classification algorithm by employing tree bitmap of multi-bit trio. We divided prefixes of searching fields and rule into multi-bit stride, and perform a rule searching with multi-bit of fixed size. The proposed scheme can reduce the access times taking for rule search by employing indexing key in a fixed size of upper bits of rule prefixes. We also employ a marker prefixes in order to remove backtracking during searching a rule. In this paper, we generate two dimensional random rule set of source address and destination address using routing tables provided by IPMA Project, and compare its memory usages and performance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.141-146
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• 2012

This paper introduces development of multi-rotor system and vision based autonomous landing system. Multi-rotor platform is modeled by rigid body motion with Newton Euler concept. Also Multi-rotor platform is simulated and tuned by LQR control algorithm. Vision based Autonomous Landing system uses a single camera that is mounted Multi-rotor system. Augmented reality algorithm is used as marker detection algorithm and autonomous landing code is test with GCS for the precision landing.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.6
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• pp.43-50
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• 2007

In this paper we propose a method that identifies users at H.264 streaming using watermarking with fingerprints. The watermark can efficiently reduce the potential danger of forgery or alteration. Especially a biometric watermark has various advantages. Among entire biometric characteristics, the fingerprint is the most convenient and economical. In this paper we propose a novel fingerprint-based watermarking technique that can survive under very low bit-rate compression. The proposed algorithm consists of enhancement of a fingerprint image, the watermark generation using the extracted feature coordinates, watermark insertion using discrete wavelet transform, and authentication. The proposed algorithm can achieve robust watermark extraction against 0.264 compressed videos.

• Journal of Digital Contents Society
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• v.1 no.1
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• pp.53-64
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• 2000

This paper is related to color image segmentation scheme which makes it possible to achieve the excellent segmented results by block-based segmentation using Y/C bit-plane summation image. First, normalized chrominance summation image is obtained by normalizing the image which is summed up the absolutes of color-differential values between R, G, B images. Secondly, upper 2 bits of the luminance image and upper 6bits of and the normalized chrominance summation image are bitwise operated by the pixel to generate the Y/C bit-plane summation image. Next, the Y/C bit-plane summation image divided into predetermined block size, is classified into monotone blocks, texture blocks and edge blocks, and then each classified block is merged to the regions including one more blocks in the individual block type, and each region is selectively allocated to unique marker according to predetermined marker allocation rules. Finally, fine segmented results are obtained by applying the watershed algorithm to each pixel in the unmarked blocks. As shown in computer simulation, the main advantage of the proposed method is that it suppresses the over-segmentation in the texture regions and reduces computational load. Furthermore, it is able to apply global parameters to various images with different pixel distribution properties because they are nonsensitive for pixel distribution. Especially, the proposed method offers reasonable segmentation results in edge areas with lower contrast owing to the regional characteristics of the color components reflected in the Y/C bit-plane summation image.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.722-723
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• 2015

스마트 기기의 확산으로 인해, 보다 다양한 애플리케이션이 개발되고 있다. 증강현실 기법 역시 이미지를 마커로 활용할 수 있게 발전됨에 따라, 광고나 전시 등에서 많이 활용되고 있다. 구현된 포토시스템은 이미지 인식 기반으로 하여, 3D모델과 함께 사진을 찍을 수 있다. 세종문화회관에서 개최된 콘텐츠 전시회에서는 로고 이미지를 이동이 용이한 폼에 부착하여 활용함으로서 브랜드 광고효과도 볼 수 있었다. 본 연구는 스마트 기기를 이용하여, 전시장에서 색다른 포토존 서비스를 제공함으로서, 증강현실 콘텐츠의 새로운 활용 사례를 제시하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1567-1570
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• 2013

최근 혼합현실 기반의 다양한 콘텐츠의 생산이 활성화 되고 있다. 이러한 콘텐츠는 실세계의 촬영 영상과 가상의 영상을 합성하는 기법으로 이를 위해서는 실세계의 촬영 영상과 마커 또는 생체 정보등의 객체를 이용하여 영상 합성을 통하여 구현되는 것이 일반적이다. 본 논문에서는 이러한 혼합영상에서의 가상영상 합성을 위해 스테레오 카메라를 이용, 영상의 객체 깊이를 측정하는 시스템을 구현한다.

• The KIPS Transactions:PartB
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• v.12B no.3 s.99
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• pp.239-246
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• 2005

Biologist must have to do 2DGE biological experiment for Protein Search and Analysis. This experiment coming into being 2 dimensional image. 2DGE (2D Gel Electrophoresis : two dimensional gel electrophoresis) image is the most widely used method for isolating of the objective protein by comparative analysis of the protein spot pattern in the gel plane. The process of protein spot analysis, firstly segment protein spots that are spread in 2D gel plane by image processing and can find important protein spots through comparative analysis with protein pattern of contrast group. In the algorithm which detect protein spots, previous 2DGE image analysis is applies gaussian fitting, however recently Watersheds region based segmentation algorithm, which is based on morphological segmentation is applied. Watersheds has the benefit that segment rapidly needed field in big sized image, however has under-segmentation and over-segmentation of spot area when gray level is continuous. The drawback was somewhat solved by marker point institution, but needs the split and merge process. This paper introduces a novel marker search of protein spots by watersheds-based hierarchical threshold, which can resolve the problem of marker-driven watersheds.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.12
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• pp.1209-1216
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• 2009

This paper presents the pose estimation of a small UAV utilizing visual information from low cost cameras installed indoor. To overcome the limitation of the outside flight experiment, the indoor flight test environment based on multi-camera systems is proposed. Computer vision algorithms for the proposed system include camera calibration, color marker detection, and pose estimation. The well-known extended Kalman filter is used to obtain an accurate position and pose estimation for the small UAV. This paper finishes with several experiment results illustrating the performance and properties of the proposed vision-based indoor flight test environment.