• Information and Communications Magazine
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• v.24 no.4
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• pp.15-26
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• 2007

멀티미디어 기술이 빠르게 발전함에 따라 보다 사실감 있는 콘텐츠의 수요가 급증하고 있다. 특히 2차원의 단방향 방송시스템에서 사용자의 요구에 따라 콘텐츠의 내용이 바뀌는 상호작용이 가능한 시스템이 활발히 연구되고 있다. 이러한 기술 중에 다시점 비디오는 여러 대의 카메라로 한 장면을 동시에 촬영한 영상으로, 사용자의 요구에 따라 시청 시점을 자유로이 선택할 수 있는 차세대 방송기술이다. 그러나 데이터의 양이 방대하여 다양한 서비스에 적용이 쉽지 않다. 이에 따라 MPEG(moving picture experts group)과 JVT (joint video team) 그룹은 다시점 비디오 부호화(multi-view video coding)의 국제 표준화 작업을 진행하고 있다. 2001년 12월에 시작하여 2007년 1월 국제회의까지 다시점 비디오 부호화의 요구사항, 부호화 조건, 테스트영상 선정, 세부 기술 제안 및 선정 등 국제 기술의 표준화를 위한 활동이 진행되었다. 그리고 향후 2008년까지 최종 국제 규격안이 제정될 예정이다.

• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.1-9
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• 2007

Cellular operators develop high speed mobile internet and multi-function cellular phones to activate new business model based on mobile internet services. Domestic cellular operators evolve their mobile networks from cdma2000-1x and EvDo to HSDPA to activate high speed mobile internet services. They also develop mobile internet platforms such as WIPI, BREW, and J2ME on multi-function cellular phones having multimedia solutions such as camera, MP3, MPEG, 3D game engine, DMB, PAN such as bluetooth, IrDA, W-LAN, and location information using GPS. But, content providers have problems of redevelopment of the same mobile internet application on different mobile internet platforms provided by cellular operators. In this paper, we develop conversion solutions for interoperability of mobile internet applications on WIPI and BREW using an one-pass compiler. We confirm the performance the proposed conversion solutions for the API conversion rate, the converted file size, and the full conversion time using the popular mobile games which are the killer applications on WiPI and BREW.

• Journal of Korea Multimedia Society
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• v.12 no.5
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• pp.664-676
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• 2009

As data broadcasting has become available, diverse contents can now be provided through digital TV, IPTV and DMB; yet it is true in the current situation that killer contents are insufficient that can satisfy users. On the contrary, in case of the web, with the advent of web 2.0 aiming at user-centered services, the contents market has grown greatly. The ideas and technologies of Web 2.0, if gratified into data broadcasting, are expected to make a contribution to the vitalization of contents. This paper proposes a method of using RSS, as a concrete example of applying web 2.0 to data broadcasting. Accordingly, we have developed a system for producing data services for the ground wave DMB data broadcasting, by using RSS at the stage of authoring news and the like, for which provision of the latest information is important. And for IPTV, we have developed a data broadcasting application so that users can select the RSS they want, as well as a creation system for using RSS at the authoring stage. It is anticipated that the application of RSS by means of the system will simplify the authoring process, making easy the provision of the latest information through the web, and thereby making possible the provision of diverse services to users.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.4
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• pp.777-781
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• 2005

It is issued that protecting and managing a copyright are very important to a digitization of multimedia content. All of these techniques are for developing solution about protection and management of the copyright and media service. These have been at the head of the growth of the whole media service, but cause problems such as a illegal copy and distribution. To solve these problems, researchers are performing many projects. We analyze the trend of a multimedia service IPMP(Intellectual Property Management and Protection), DMP(Digital Media Project), ENTHRONE(End-to-end Qos through Integrated Management of Content, Networks and Terminals), and DRM(Digital Rights Management).

• The Journal of the Korea Contents Association
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• v.17 no.5
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• pp.1-7
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• 2017

Joint Collaborative Team on Video Coding (JCT-VC) of ISO/IEC MPEG and ITU-T developed the HEVC Screen Content Coding (HEVC SCC) standard as the HEVC extension for the screen content video coding. The Intra Block Copy (IBC) is the most effective tool adopted in HEVC SCC and predicts current block from already reconstructed neighboring blocks in the same picture. To reduce the amount of data in BV (Block Vector) to be transmitted, a BV predictor (BVP) is used to generate the BV differences in the IBC BV coding. In this paper, we analyze the current BV prediction process using HEVC reference software SCM-2.0 and SCM-4.0. Based on the analysis results, we propose an improved BVP candidate selection algorithm by adding a search process for adjacent BVs in addition to the existing spatial BVP candidates. Experimental results show that the BD-rate reduction of our proposed improvements ranges from 0.2% to 1%.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.1
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• pp.29-38
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• 2012

Due to the rapid development of network environment and wireless communication technology, the distribution of digital video has made easily and the importance of the protection for digital video has been increased. This paper proposes the digital video encryption system based on multiple chaos maps for MPEG-2 video encoding process. The proposed method generates secret hash key of having 128-bit characteristics from hash chain using Tent map as a basic block and generates $8{\times}8$ lattice cipher by applying this hash key to Logistic map and Henon map. The method can reduce the encryption overhead by doing selective XOR operations between $8{\times}8$ lattice cipher and some coefficient of low frequency in DCT block and it provides simple and randomness characteristic because it uses the architecture of combining chaos maps. Experimental results show that PSNR of the proposed method is less than or equal to 12 dB with respect to encrypted video, the time change ratio, compression ratio of the proposed method are 2%, 0.4%, respectively so that it provides good performance in visual security and can be applied in real time.

• International Journal of Contents
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• v.4 no.2
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• pp.24-28
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• 2008

In this paper, we propose a new approach for content-based video retrieval using non-parametric based motion classification in the shot-based video indexing structure. Our system proposed in this paper has supported the real-time video retrieval using spatio-temporal feature comparison by measuring the similarity between visual features and between motion features, respectively, after extracting representative frame and non-parametric motion information from shot-based video clips segmented by scene change detection method. The extraction of non-parametric based motion features, after the normalized motion vectors are created from an MPEG-compressed stream, is effectively fulfilled by discretizing each normalized motion vector into various angle bins, and by considering the mean, variance, and direction of motion vectors in these bins. To obtain visual feature in representative frame, we use the edge-based spatial descriptor. Experimental results show that our approach is superior to conventional methods with regard to the performance for video indexing and retrieval.

• Journal of Broadcast Engineering
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• v.14 no.4
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• pp.488-500
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• 2009

In this paper, we study on making a use of value-added services using DTV closed caption data. Note that Closed-Captioning service helps to bridge "digital divide" through extending broadcasting accessibility of a neglected class such as hearing-impaired person and foreigner. In Korea, DTV Closed Captioning standard was developed in June 2007, and Closed Captioning service should be provided by an enforcing law in all broadcasting services in April 2008. Here, we describe the method of extracting a caption data from MPEG-2 Transport Stream of ATSC-based digital TV signal and generating a caption file using the extracted caption data and time information. In addition, we present the segmentation method of broadcasting content using caption file. Experimental results show that implemented S/W tool provides the feasibility of the proposed methods and the usability of closed caption for a variety of data application service.

• Journal of Broadcast Engineering
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• v.8 no.4
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• pp.465-472
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• 2003

In this paper we propose the structure of MPEG-4 multimedia player platform for Terrestrial Digital Multimedia Broadcasting (DMB) Service. Korea will launch DMB service at next 2004 you based on Eureka-147 Digital Audio Broadcasting (DAB) Service System. This new mobile multimedia broadcasting services provide not only high quality digital audio broadcasting services, but also various multimedia data broadcasting services including high quality video. For the sake of MPEG-4 Systems technologies, it will provide an interactive service to users in the near future. Therefore it terminal shall have various functionalities as well as playing audio-visual contents. However there is no precedence standard for such mobile interactive multimedia broadcasting system. Therefore it is very import to provide the multimedia player platform of DMB service for accelerating the development process of commercial terminal and providing a direction of next DMB terminal structure.

• Broadcasting and Media Magazine
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• v.16 no.4
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• pp.59-71
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• 2011

오디오와 음성 압축 기술적 근간은 서로 다르지만, 최근의 모바일 멀티미디어 기기 시장의 컨버전스 현상에 따라 압축하고자 하는 신호가 혼용되고 있으며, 비슷한 목표 전송률과 음질로 수렴하고 있다. 현재는 동일 기기에서 서로 다른 압축 기술을 적용하고 있으나, 음성과 음악이 동시에 서비스 되는 멀티미디어 기기에서는 단일 압축 방식으로 처리하고자 하는 이슈가 부각되고 있다. 특히, 스마트 폰 및 음악 콘텐츠 포탈 서비스의 대중화를 고려할 때, 음성 및 음악 신호 모두를 효율적으로 압축하는 음악 및 음성 신호의 융합 압축 기술이 더욱 필요해 보인다. 본 고에서는 MPEG 오디오 그룹에서 가장 최근 진행한 Unified Speech and Audio Coding(USAC)의 탄생 배경 및 표준화 현황을 소개한다. USAC는 64kbps 이하에서 기술적으로 최고 성능을 지닌 AMR-WB+ 및 HE-AAC v2보다도 우월한 음질을 보이며, 높은 비트율에서도 동등한 음질을 보장한다. 이런 우수한 음질에 기여한 USAC의 스위칭 구조와 더불어 기술적으로 향상된 주요 모듈인 파라미터 기반 스테레오 및 고주파 압축, 그리고 엔트로피 코딩 방식에 대해서 살펴 본다. 향후, 다양한 오디오 신호를 효율적으로 압축하는 USAC는 디지털 라디오, 모바일 TV, 그리고 오디오 북과 같은 사용자 시나리오에서 사용될 확률이 높아 보인다. 또한, USAC는 배경 잡음이나 배경 음악이 있는 경우에도 성능이 우수하기 때문에 YouTube 및 podcast 등과 같이 사용자가 콘텐츠를 생성할 때도 유용하게 사용 될 수 있다.