• The KIPS Transactions:PartB
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• 제12B권6호
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• pp.637-646
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• 2005

Most of the multimedia contents for DBM services art provided as MPEG-2 bit streams. However, they have to be transcoded to H.264 bit streams for practical services because the standard video codec for DMB is H.264. The existing transcoder architecture is Cascaded Pixel-Domain Transcoding Architecture, which consists of the MPEG-2 dacoding phase and the H.264 encoding phase. This architecture can be easily implemented using MPEG-2 decoder and H.264 encoder without source modifying. However. It has disadvantages in transcoding time and DCT-mismatch problem. In this paper, we propose two kinds of transcoder architecture, DCT-OPEN and DCT-CLOSED, to complement the CPDT architecture. Although DCT-OPEN has lower PSNR than CPDT due to drift problem, it is efficient for real-time transcoding. On the contrary, the DCT-CLOSED architecture has the advantage of PSNR over CPDT at the cost of transcoding time.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제19권4호
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• pp.825-840
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• 2015

Adaptive bitrate (ABR) streaming technology has become an important and prevalent feature in many multimedia delivery systems, with content providers such as Netflix and Amazon using ABR streaming to increase bandwidth efficiency and provide the maximum user experience when channel conditions are not ideal. Where such systems could see improvement is in the delivery of live video with a closed loop cognitive control of video encoding. In this paper, we present streaming camera system which provides spatially and temporally adaptive video streams, learning the user's preferences in order to make intelligent scaling decisions. The system employs a hardware based H.264/AVC encoder for video compression. The encoding parameters can be configured by the user or by the cognitive system on behalf of the user when the bandwidth changes. A cognitive video client developed in this study learns the user's preferences(i.e. video size over frame rate) over time and intelligently adapts encoding parameters when the channel conditions change. It has been demonstrated that the cognitive decision system developed has the ability to control video bandwidth by altering the spatial and temporal resolution, as well as the ability to make scaling decisions.

• Journal of the Institute of Electronics and Information Engineers
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• 제52권5호
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• pp.147-154
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• 2015

In this paper, we employed a model which defines the sensitivity according to the background luminance, so called JND (Just Noticeable Difference), and applied to the video coding. The proposed method finds out the maximum possible quantization parameter for the current unit based on the threshold of JND model and reduce the bitrate with similar perceptual quality. It selects the higher quantization parameter and reduce the bitrate when the reconstructed signal which is coded with higher quantization parameter is in a range of allowance based on the JND threshold, i.e. the signal has the similar perceptual quality compared to that is coded with the initial quantization parameter. The proposed algorithm was implemented on HM16.0, which is a reference software of the latest video coding standard HEVC (High Efficiency Video Coding) and the coding performance was evaluated. Compared to HM16.0, the proposed algorithm achieved maximum 20.21% and 6.18% of average bitrate reduction with the similar perceptual quality.

• Proceedings of the Korean Information Science Society Conference
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• 한국정보과학회 2003년도 가을 학술발표논문집 Vol.30 No.2 (3)
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• pp.316-318
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• 2003

JPEG 2000표준을 이용하여 계산상 효율적이면서도 DSP에 적합한 영상 압축 알고리즘을 개발한다. 개발될 기법이 갖는 가장 큰 장점은 비교적 복잡한 연산량을 필요로 하여 실시간 동영상 부호화기에 사용되지 못하고 있는 JPEG 2000 알고리즘을 DSP에 맞게 구현함으로써 고화질의 동영상을 실시간으로 처리할 수 있게 한다. 또한 사용자의 요구 및 사양에 맞추어 보다 효과적으로 컨텐츠를 제공하기 위해, 시, 공간적 스케일러비티를 지원하는 코덱을 개발하여 사용자의 요구와 필요 서비스에 따라 적절한 품질의 비디오를 제공함으로써 더 많은 응용에 쉽게 적용시킬 수 있는 방법들을 제시한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제5권3호
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• pp.405-417
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• 2001

In this paper, since we currently using surveillance system of analog type bring about waste of resource and efficiency deterioration problems, we describe new solution that design and implementation to the digital surveillance system of new type applying compression techniques and encoding techniques of image data using MPEG-2 international standard. Also, we proposed fast motion estimation algorithm requires much less than the convectional digital surveillance camera system. In this paper a fast motion estimation algorithm is proposed the MPEG-2 video encoding. This algorithm is based on a hybrid use of the block matching technique and gradient technique. Also, we describe a method of moving object extraction directly using MPEG-2 video data. Since proposed method is very simple and requires much less computational power than the conventional object detection methods. In this paper we don't use specific H/W and this system is possible only software encoding, decoding and transmission real-time for image data.

• Journal of the Institute of Electronics and Information Engineers
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• 제52권12호
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• pp.167-173
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• 2015

This paper presents a study on the Full-HD HEVC(High Efficiency Video Coding) encoder IP(Intellectual Property) design. The designed IP is for HEVC main profile 4.1, and performs encoding with a speed of 60 fps of full high definition. Before hardware and software design, overall reference model was developed with C language, and we proposed a parallel processing architecture for low-power consumption. And also we coded firmware and driver programs relating IP. The platform for verification of developed IP was developed, and we verified function and performance for various pictures under several encoding conditions by implementing designed IP to FPGA board. Compared to HM-13.0, about 35% decrease in bit-rate under same PSNR was achieved, and about 25% decrease in power consumption under low-power mode was performed.

• Broadcasting and Media Magazine
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• 제15권1호
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• pp.24-36
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• 2010

Nowadays, digital broadcasting providers have plan to extend their service area to 3D broadcasting without exchanging conventional system and equipments. The maintenance of backward compatibility to conventional 2D broadcasting system is very importance issue on digital broadcasting. To satisfy the requirement, highly-optimized MPEG-2 video encoder is essential for coding left-view and new video coding techniques having higher performance than MPEG-4 AVC/H.264 is needed for right-view since terrestrial broadcasting system has very limited and fixed bandwidth. In this paper, conventional video coding algorithms and new video coding algorithms are analyzed to present a capable solution for the best quality stereoscopic 3D broadcasting keeping backward compatibility within the bandwidth.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제17권7호
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• pp.1633-1638
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• 2013

The mobile phone has now evolved into an effective multimedia devices to watch video content with your PC in addition to the calling features. Thus, the effectiveness of the video content streaming services smartphone will be available. And content should be able to deliver effectively. Be provided with textbook images and video of the speaker means that the effective content delivery. In this paper, we propose a integrated video management system that can be real-time VOD services on the Internet as input Multi-Source of audio-video, video content encoding system to meet the requirements of the above two.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.830-832
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• 2013

The mobile phone has now evolved into an effective multimedia devices to watch video content with your PC in addition to the calling features. Thus, the effectiveness of the video content streaming services smartphone will be available. And content should be able to deliver effectively. Be provided with textbook images and video of the speaker means that the effective content delivery. In this paper, we propose a integrated video management system that can be real-time VOD services on the Internet as input Multi-Source of audio-video, video content encoding system to meet the requirements of the above two.

• Journal of Broadcast Engineering
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• 제8권3호
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• pp.306-316
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• 2003

When a cinema being composed of 24 frames/sec is converted to NTSC video or TV program, several fields we repeated to have 60 fields/sec, which is called the telecine or 3:2 pull-down. Hence, when encoding the telecine NTSC video into MPEG format, if we convert it into the original 24 frames/sec Progressive cinema, then we can save 20% of bits compared to the case of encoding all the 60 fields. In this Paper, we propose an algorithm for performing the inverse telecine by using the properties of the frames. Specifically, the algorithm exploits the fact that there Is much Inconsistency between the even and odd fields in the case of telecine frame, which results in high magnitude at the Nyquist frequency In the vertical direction. The experiment shows that the proposed algorithm performs very well regardless of the quality of video with a very few computations, whereas the conventional motion based method requires much computational complexity and its performance is degraded when the video is of low (eg. VHS) quality.