• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.07a
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• pp.43-45
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• 2015

본 논문은 최근 관심이 높아지고 있는 UHD 콘텐츠 제작과 관련하여 8K UHD 비디오 렌더링 시스템을 제안한다. 현재 시장은 4K UHD 비디오를 중심으로 편집되고 있는 실정을 감안하여, 기존의 상용 UHD 편집 S/W 기반에서 4K UHD 단위의 편집은 유지한 상태로 8K UHD 를 편집하는 환경을 제안하고, 이를 비디오 렌더링 시스템으로 설계하고 구현하였다. 본 비디오 렌더링 시스템은 상용 편집 S/W 기반에서 동작 가능하고, 특히 압축된 비디오 스트림의 디코딩과 비디오 렌더링(합성)을 GPU 기반으로 구현하여 시스템 성능을 효율적으로 사용하였다. 향후 8K UHD 가 시장에 보급되고 시스템 자원이 함께 발전하기 전까지 4K UHD 와 8K UHD 를 잇는 중간 관점에서 활용될 수 있으며, 아울러 4 채널의 4K UHD 비디오를 동시에 편집/모니터링 하는 용도로도 활용이 가능하다.

• Broadcasting and Media Magazine
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• v.19 no.2
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• pp.46-56
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• 2014

UHD(Ultra High Definition) 관련기술이 성숙되면서 최근 UHD 방송은 HD(High Definition) 방송 이후 차세대 실감 방송 서비스로 확고하게 자리를 잡아 가고 있다. 이러한 영향으로 UHDTV를 중심으로 UHD 방송장비의 상용화가 점차 확대되고 있고, 국내외 여러 방송사업자들은 서비스 상용화 준비를 서두르고 있다. CJ헬로비전을 포함한 국내 케이블 방송사들은 유일하게 UHD 방송 표준화를 조기에 완료하였고 이를 기반으로 상용 서비스를 준비해 왔기에 세계최초로 2014년 4월에 4K-UHD 방송을 상용화한다. 케이블 방송에서 UHD 방송의 조기 상용화와 표준화는 전송방식의 변경이나 네트워크에 대한 대규모 투자가 없이 UHD 방송을 쉽게 제공할 수 있는 구조이기 때문에 가능했다. UHD 방송은 방송산업 가치사슬의 전 부분에 걸쳐 영향을 주기 때문에 케이블의 4K-UHD 방송 상용화를 계기로 국내 방송산업의 활성화에 기여할 것이다. 본 고에서는 세계최초로 상용화 하는 CJ헬로비전의 케이블 4K-UHD 방송 서비스와 케이블 UHD 방송 표준에 대해서 알아본다.

• Journal of Broadcast Engineering
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• v.15 no.4
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• pp.563-581
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• 2010

In this paper, we perform subjective visual quality assessments on UHD video for UHD TV services and analyze the assessment results. Demands for video services have been increased with availabilities of DTV, Internet and personal media equipments. With this trend, the demands for high definition video have also been increasing. Currently, 2K-HD ($1920{\times}1080$) video have been widely consumed over DTV, DVD, digital camcoders, security cameras and other multimedia terminals in various types, and recently digital cinema contents of 4K-UHD($3840{\times}2160$) have been popularly produced and the cameras, beam projects, display panels that support for 4K-UHD video start to come out into multimedia markets. Also it is expected that 4K-UHD service will appear soon in broadcasting and telecommunications environments. Therefore, in this paper, subjective assessments of visual quality on resolutions, color formats, frame rates and compression rates have been carried to provide basis information for standardization of signal specification of UHD video and viewing environments for future UHDTV. As the analysis on the assessments, UHD video exhibits better subjective visual quality than HD by the evaluators. Also, the 4K-UHD test sequences in YUV444 shows better subjective visual quality than the 4K-UHD test sequences in YUV422 and YUV420, but there is little perceptual difference on 4K-UHD test sequences between YUV422 and YUV420 formats. For the comparison between different frame rates, 4K-UHD test sequences of 60fps gives better subjective visual quality than those of 30fps. For bit-depth comparison, HD test sequences in 10-bit depth were little differentiated from those in 8-bit depth in subject visual quality assessment. Lastly, the larger the PSNR values of the reconstructed 4K-UHD test sequences are, the higher the subjective visual quality is. Against the viewing distances, the differences among encoded 4K-UHD test sequences were less distinguished in longer distances from the display.

• Journal of Digital Convergence
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• v.12 no.8
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• pp.271-282
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• 2014

The recent flow of broadcasting technology, HDTV and 3DTV are being followed to develop UHDTV. UHDTV has established itself as the new paradigm. In Korea, the 4K-UHDTV experimental terrestrial broadcasting and cable and satellite TV services are being carried out in the present. 4K-UHD content creation workflow to enable a systematic formulation is needed. In this study, Through expert opinion 4K-UHD production workflow to derive the important topics and Hierarchical analysis methods (AHP, Analytic Hierarchy Process) is applied to 4K-UHD content creation is important to consider the items were compared to each other. The upper layer has a content creation workflow planning side, the media file management side and operational aspects of the selection and production equipment were classified. In the lower layer, UHD STAFF roles between production and training, media management, selection and operation of the storage device was evaluated in a relatively important. In addition, real-time 4K-UHD suggested workflow for production.

• Journal of Broadcast Engineering
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• v.24 no.1
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• pp.118-131
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• 2019

In order to provide 8K UHD contents of terrestrial broadcasting with a large capacity, the terrestrial broadcasting system has various problems such as limited bandwidth and so on. To solve these problems, UHD contents transmission technology has been actively studied, and an 8K UHD broadcasting system using terrestrial broadcasting network and communication network has been proposed. The proposed technique is to solve the limited bandwidth problem of terrestrial broadcasting network by segmenting 8K UHD contents and transmitting them to heterogeneous networks through hierarchical separation. Through the terrestrial broadcasting network, the base layer corresponding to FHD and the additional enhancement layer data for 4K UHD are transmitted, and the additional enhancement layer data corresponding to 8K UHD is transmitted through the communication network. When 8K UHD contents are provided in such a way, user can receive up to 4K UHD broadcasting by terrestrial channels, and also can receive up to 8K UHD additional communication networks. However, in order to transmit the 4K UHD contents within the allocated bit rate of the domestic terrestrial UHD broadcasting, the compression rate is increased, so a certain level of image deterioration occurs inevitably. Due to the nature of UHD contents, video quality should be considered as a top priority over other factors, so that video quality should be guaranteed even within a limited bit rate. This requires packet scheduling of content generators in the broadcasting system. Since the multiplexer sends out the packets received from the content generator in order, it is very important to make the transmission time and the transmission rate of the process from the content generator to the multiplexer constant and accurate. Therefore, we propose a variable transmission scheduler between the content generator and the multiplexer to guarantee the image quality of a certain level of UHD contents in this paper.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.11a
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• pp.203-205
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• 2014

UHD 영상 콘텐츠는 FHD 영상에 비해 생생하고 더 좋은 고화질의 영상을 제공하지만 영상정보의 데이터 양은 4K UHD 경우 4 배 이상이다. 이러한 초대용량의 UHD 영상을 기존의 병렬/분산 처리를 이용하여 비디오 코딩 한다면 UHD 의 초대용량 특성으로 인하여 연산량 부하가 발생하게 된다. 따라서 UHD 영상은 기존의 분산처리 방식이 아닌 초대용량 데이터를 빠르게 처리 할 수 있는 새로운 분산 처리기술이 필요하다. 본 논문은 UHD 콘텐츠를 빠르게 트랜스코딩 할 수 있는 클라우드 기반 UHD 영상 트랜스코딩 시스템을 제안한다. 본 논문에서 제안하는 UHD 영상 트랜스코딩 시스템은 다음 3 가지 패킷 분석기, 분산 트랜스코더, 스트림 합성기로 구성된다. 패킷 분석기는 입력 영상을 분석하여 오디오와 비디오 스트림을 분할하고 비디오 스트림은 분산처리를 할 수 있도록 영상 패킷을 분할한다. 분산 트랜스코더는 클라우드 환경을 이용하여 분할된 영상 패킷들을 분산 디코드 및 인코드 처리한다. 스트림 합성기는 트랜스코딩이 완료된 비디오 스트림과 패킷 분석기에서 획득하였던 오디오 스트림을 합성하는 기능을 한다. 제시하는 방안을 적용하여 클라우드 기반 영상 트랜스 코딩 시스템을 구현하였으며, 구현된 시스템은 대용량의 UHD 영상을 빠른 속도로 트랜스코딩이 가능하다.

• Journal of Broadcast Engineering
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• v.25 no.5
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• pp.789-797
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• 2020

In this paper, we propose a protocol structure of a portable 4K Ultra High Definition (UHD) broadcast relay device that utilizes a 5G mobile communication network as a transport channel, and construct a prototype to conduct a broadcast relay performance test through a 5G mobile communication network. The test shows that the encoding time of the 4K UHD encoder is from a minimum of 86.28ms to a maximum of 88.41ms, the relay delay time in the 5G mobile communication network is 13.645ms on average, the delay variation is 17.49ms, and the glass-to-glass delay time is 289.90 on average, the delay variation is 27.63ms. Using the developed prototype, a relay test between Seoul and Anseong is conducted, and the possibility of 4K UHD broadcasting through a 5G mobile communication network is confirmed.

• Journal of Broadcast Engineering
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• v.27 no.6
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• pp.914-922
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• 2022

In this paper, we construct a commercial 4K UHD(Ultra High Definition) streaming device that utilizes a 5G mobile communication network as a transport channel and conduct a streaming performance test. It uses RTP(Realtime Transport Protocol) which has transmission quality monitoring capability as a transmission protocol to apply adaptive streaming. In addition, it provides the function to adjust the encoding rate of the video signal so that encoding can be optimized for the change in the bandwidth of the transmission channel. Through the performance test, it is confirmed that the H.265 encoding rate for 4K UHD signal is 48.69Mbps, the average glass-to-glass delay time is 293.60ms, and the average time difference between video and audio for lip sync is 120ms. With the result of performance test, it is shown that the streaming device is applied to 4K UHD Streaming device over 5G mobile communication network.

• Journal of Digital Contents Society
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• v.16 no.2
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• pp.227-234
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• 2015

Recently, there is more and more demand on broadcasting display environment that provides a sense of realism basically with high quality and high definition as in UHDTV, so various kinds of 4K cameras have been released. Super 35mm sensor 4K/UHD cameras being generally used can be usefully applied to the single camera-based system such as advertisements, dramas, nature documentaries, and culture programs. However, in the multicamera-based system such as entertaining programs, sports, and concerts, relay broadcasting may face limitations as there are restrictions of close-up or tight shots according to the distance. Besides, 4K lenses are not enough compared with the previous HD lenses' group, so there are limitations in camera photographing shots that have been realized in HD filming. Therefore, to complement this, the use of 2/3 inch sensor 4K/UHD cameras is being demanded, and it is also needed to use various lenses' groups to produce UHD image contents. Accordingly, this study used Grass Valley's LDX 4K/UHD camera to analyze its applicability based on the picture quality test at the use of HD lenses in 2/3 sensors and also the possibility of its efficient application.

• Journal of IKEEE
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• v.19 no.1
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• pp.1-9
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• 2015

This paper proposes the design of sub-pixel interpolation circuit for real-time multi-decoder supporting 4K-UHD video images. The proposed sub-pixel interpolation circuit supports H.264, MPEG-4, VC-1 and new video compression standard HEVC. The common part of the interpolation algorithm used in each video compression standard is shared to reduce the circuit size. An intermediate buffer is effectively used to reduce the circuit size and optimize the performance. The proposed sub-pixel interpolation circuit was synthesised by using 130nm standard cell library. The synthesized gate-level circuit consists of 122,564 gates and processes 35~86 image frames per second for 4K-UHD video at the maximum operation frequency of 200MHz. Therefore, the proposed circuit can process 4K-UHD video in real time.