• ETRI Journal
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• 제31권1호
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• pp.10-20
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• 2009

In this paper, a video broadcasting system between a home-server-type device and a mobile device is proposed. The home-server-type device can automatically extract semantic information from video contents, such as news, a soccer match, and a baseball game. The indexing results are utilized to convert the original video contents to a digested or arranged format. From the mobile device, a user can make recording requests to the home-server-type devices and can then watch and navigate recorded video contents in a digested form. The novelty of this study is the actual implementation of the proposed system by combining the actual IT environment that is available with indexing algorithms. The implementation of the system is demonstrated along with experimental results of the automatic video indexing algorithms. The overall performance of the developed system is compared with existing state-of-the-art personal video recording products.

• ETRI Journal
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• 제26권2호
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• pp.122-135
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• 2004

Although frame-based MPEG-4 video services have been successfully deployed since 2000, MPEG-4 video coding is now facing great competition in becoming a dominant player in the market. Object-based coding is one of the key functionalities of MPEG-4 video coding. Real-time object-based video encoding is also important for multimedia broadcasting for the near future. Object-based video services using MPEG-4 have not yet made a successful debut due to several reasons. One of the critical problems is the coding complexity of object-based video coding over frame-based video coding. Since a video object is described with an arbitrary shape, the bitstream contains not only motion and texture data but also shape data. This has introduced additional complexity to the decoder side as well as to the encoder side. In this paper, we have analyzed the current MPEG-4 video encoding tools and proposed efficient coding technologies that reduce the complexity of the encoder. Using the proposed coding schemes, we have obtained a 56 percent reduction in shape-coding complexity over the MPEG-4 video reference software (Microsoft version, 2000 edition).

• 방송공학회논문지
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• 제13권2호
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• pp.179-187
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• 2008

본 논문에서는 영상 특성에 제약 없이 적용 가능한 SVC 기반 범용 품질 메트릭을 제안한다. 이종 환경에서의 비디오 콘텐츠 소비가 증가하면서 서비스 품질(Quality of Service, QoS)은 중요한 이슈 중 하나가 되었다. 또한 스케일러블 비디오 코딩(Scalable Video Coding, SVC)은 하나의 부호화된 비트스트림이 공간적, 시간적 그리고 품질적으로 다양한 확장이 가능하다는 장점을 이유로 이종 환경에서 적응성이 높은 영상 부호화 기술로 주목받고 있다. 제한된 환경에서의 서비스 품질 보장을 위해서는 서비스의 사용 주체인 사람이 느끼는 주관적 비디오 품질이 고려되어야 한다. 주관적 품질은 영상의 시간적, 공간적 특성 모두에 영향을 받기 때문에 영상의 특성에 대한 고려 역시 중요하다. 제안하는 방법의 효율성은 실험을 통해 측정된 주관적 품질 값과 제안된 품질 메트릭을 이용해 측정된 품질 지수 사이의 상관계수를 이용하여 검증하였으며 제안하는 품질 메트릭은 SVC의 품질 확장 결정 기준으로 사용될 수 있다.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.155-158
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• 2007

In this paper, we solved the underestimation problem of PSNR, which is caused by repeated frames, by easily synchronizing original and decoded frames using the proposed marks. Also we propose full-reference system which can be applied for measuring the quality of various kinds of video communication systems, e.g. wireless handsets, mobile phones and applications for PC. In addition, we propose a new video quality assessment metric using video communication parameters, i.e. frame rate and delay. According to the experiments, the proposed metric is not only appropriate for real-time video communication systems but also shows better correlation with the subjective video quality assessment than PSNR. The proposed measuring system and metric can be effectively used for measuring and standardizing the video quality of future communications.

• 한국통신학회논문지
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• 제33권1C호
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• pp.124-130
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• 2008

We present in this paper a method of digital watermarking for video data based on the discrete wavelet transform. In the proposed method, a watermark signal is inserted into the decompressed bitstream while detection is performed using the uncompressed video. This method allows detection if video has been manipulated or its format changed. We embed the watermark in the lowest frequency components of each frame in the un-coded video by using wavelet transform. The watermark can be extracted directly from the decoded video without access to the original video. Experimental results show that the proposed method gives the watermarked video of better quality and is robust against MPEG coding, down sampling and re-encoding to other type of video format such as MPEG4, H.264

• 한국통신학회논문지
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• 제39A권7호
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• pp.398-400
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• 2014

In this letter, we propose a cross-layer technique jointly considering modulation coding schemes (MCSs) of medium access control (MAC) layer, source significance information (SSI) and error concealment unit of application (APP) layer, and channel quality information (CQI) of physical (PHY) layer. We demonstrate the improved video quality by the proposed technique when H.264 videos are streamed over Rayleigh fading wireless channels.

• 한국멀티미디어학회:학술대회논문집
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• 한국멀티미디어학회 2012년도 춘계학술발표대회논문집
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• pp.430-430
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• 2012

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.584-587
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• 2008

In this paper, we propose a real time video codec adapter for enabling video communications with terminals having a codec which is different from each other. When multimedia services are playing with an office service phone such as a video phone or software phone which has video capability, each terminal is not being considered to have optimized video or voice codec. So when a video phone with only one type of video codec is used in the video streaming service which requires another type of codec, the streaming service is not successful without codec transformation. The real time codec adapter in this paper provides a real time code transformation which enables communication services such as video conferencing between terminals which have different codec.

• 한국인터넷방송통신학회논문지
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• 제12권5호
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• pp.67-74
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• 2012

현재 유료 동영상 콘텐츠는 보안 취약점을 이용하여 제 3자가 취득할 수 있는 문제점이 있다. 본 연구에서는 제3자의 위법적인 다운로드를 차단하기 위하여 상용화되어 사용 중인 동영상 암호화 방식을 분석하였다. 그리고 기존에 있던 방식인 주소 암호화 방식과 암호화 프로토콜을 사용하는 방식에 추가하여 프로그램 자체에서 암호화 및 복호화를 하여 송, 수신하는 방식을 제안하였다. 성능평가를 위해서 암호화를 통한 인코딩과 디코딩 지연시간을 최대한으로 줄이면서 보안 향상을 이룰 수 있는지를 가지고 기존의 방식과 비교 분석하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권11호
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• pp.4189-4202
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• 2014

In this paper, we propose a priority-based unequal error protection scheme of data partitioned H.264/AVC video with hierarchical quadrature amplitude modulation. In order to map data with higher priority onto the most significant bits of QAM constellation points, a priority sorting method categorizes different data partitions according to the unequal importance factor of encoded video data in one group of pictures by evaluated the average distortion. Then we propose a hierarchical quadrature amplitude modulation arrangement with adaptive constellation distances, which takes into account the unequal importance of encoded video data and the channel status. Simulation results show that the proposed scheme improves the received video quality by about 2 dB in PSNR comparing with the state-of-the-art unequal error protection scheme, and outperforms EEP scheme by up to 5 dB when the average channel SNR is low.