• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.9
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• pp.746-752
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• 2012

SVC layered video is consists of a Base Layer (BL) and Enhancement Layer (EL). Without the base layer decoding, the higher EL layer can not be decoded. Therefore, successful transfer of the BL is important factor for improving the SVC video data. In this paper, we propose a network coding of layered video to improve success decoding probability with the importance order of the video data over a multi-relay system. We shows that formula analysis and experimental results of the proposed network coding scheme. In addition, we shows performance of video quality according to the number of relays.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.119-126
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• 2013

Achieve real-time encryption and video data transcoding, current video encryption methods usually integrate encryption algorithm with video compression course. This paper is devoted to discussing the video encryption technology, by encrypting to avoid unauthorized person getting video data. This paper studied the H.264 entropy coding and proposed of CAVLC video encryption scheme which is combined with the process of entropy coding of H.264 CAVLC encryption scheme. Three encryption levels are proposed. In addition, a scrambling method is also proposed which makes the encrypted frames more robust in anti crack. This method showed more robust video data encryption function and compressive rate.

• The KIPS Transactions:PartA
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• v.12A no.3 s.93
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• pp.197-204
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• 2005

In this paper, we consider the transmission or variable bit rate (VBR) stored video for the distributed video streaming service over Internet. In streaming service, users often suffer from the discontinuity in playback due to the decrease in bandwidth during transmission according to bandwidth renegotiation protocol. We propose a novel transmission technique to overcome this problem for stored variable bit rate video. This scheme uses a priori information of stored VBR video to continue streaming without playback discontinuity. In addition, an approximation scheme for the buffer-bandwidth relation is proposed in order to facilitate the admission control under the proposed scheme.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• fall
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• pp.225-228
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• 2021

최근 모바일 비디오 스트리밍 서비스의 이용자 수가 증가하고 있다. 이에 따라 모바일 환경에 적합한 DASH 비디오 스트리밍 메커니즘이 연구되었고, 이것을 DQN 기법에 의해 개선한 알고리즘은 모바일 네트워크 환경에서 적절한 비디오 품질 선택을 통해 버퍼링을 크게 줄일 수 있었다. 그러나 이는 모바일 요금제로 비디오 스트리밍 서비스를 이용하는 사용자들에게 안정적인 서비스를 제공하기 어렵다. 이에 본 논문은 기존의 DQN 기법에 의한 알고리즘을 발전시켜 사용자의 모바일 요금제에 적합한 비디오 품질을 선택하는 알고리즘을 연구하고 성능 실험 결과를 분석한다. 또한 이 알고리즘을 전체 모바일 비디오 스트리밍 시스템과 통합하여 이용하도록 제안한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.2A
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• pp.114-126
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• 2011

Video streaming over wireless multi-hop networks(WMNs) contains the following challenges from channel fading and variable bandwidth of wireless channel, and it cause degradation of video streaming performance. To overcome the challenges, currently, WMNs can use Forward Error Correction (FEC) mechanism. In WMNs, traditional FEC schemes, E2E-FEC and HbH-FEC, for video streaming are applied, but it has long transmission delay, high computational complexity and inefficient usage of resource. Also, to distinguish network status in streaming path, it has limitation. In this paper, we propose monitoring-based coordination of network-adaptive hop-to-end(H2E) FEC scheme. To enable proposed scheme, we apply a centralized coordinator. The coordinator has observing overall monitoring information and coordinating H2E-FEC mechanism. Main points of H2E-FEC is distinguishing operation range as well as selecting FEC starting node and redundancy from monitored results in coordination. To verify the proposed scheme, we perform extensive experiment over the OMF(Orbit Measurement Framework) and IEEE 802.1la-based multi-hop WMN testbed, and we carry out performance improvement, 17%, from performance comparison by existing FEC scheme.

• Journal of Korea Multimedia Society
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• v.9 no.7
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• pp.864-871
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• 2006

With the advancement of the digital broadcasting and popularity of Internet, there is an increasing demand for digital data. Recently, several studies have been made on the digital watermarking for copyright protection of digital data. We propose a blind video watermarking using minimum modification of motion vectors. Conventional methods based on motion vectors do watermarking using modification of motion vectors. However, change of motion vectors results in the degradation of video quality. Thus, our proposed algorithm minimizes modification of the original motion vectors to avoid degradation of video quality using simple embedded conditions. Besides, our scheme guarantees the amount of embedded watermark data using the adaptive threshold considering the human visual characteristic. In addition, this is compatible with current video compression standards without changing the bitstream. Experimental result shows that the proposed scheme obtains better video quality than other previous algorithms by about $0.5{\sim}1.0\;dB$.

• Journal of Satellite, Information and Communications
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• v.11 no.3
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• pp.37-42
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• 2016

In this paper, in today's highly complex video and broadcast operations, broadcasters are constantly challenged to reliably deliver low-latency, high-quality video to multiscreen audiences on-air and online. The Adaptive Bit Rate (ABR) protocols enable internet video to a wide range of multiscreen devices. However, video quality is often marginal and would prove unacceptable for valued linear broadcast content delivered to the Big Screen today. The Media information processing technology advances in ABR enables service providers to take control and offer quality managed linear video services to ALL screens in the home, including the Big Screen, with a single unified IP Video infrastructure. The New Multiscreen-Assisted ABR (MSA-ABR) delivery management system proposed using Cloud based multicast-assisted ABR for a broadcast facility that performs routing of contribution content and online publishing services within a virtual, centralized cloud infrastructure.

• The Journal of the Korea Contents Association
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• v.7 no.2
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• pp.40-50
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• 2007

In this paper, we propose an efficient method for detecting and tracking multiple moving objects based on morphological region merging from real-time video sequences. The proposed approach consists of adaptive threshold extraction, morphological region merging and detecting and tracking of objects. Firstly, input frame is separated into moving regions and static regions using the difference of images between two consecutive frames. Secondly, objects are segmented with a reference background image and adaptive threshold values, then, the segmentation result is refined by morphological region merge algorithm. Lastly, each object segmented in a previous step is assigned a consistent identification over time, based on its spatio-temporal information. The experimental results show that a proposed method is efficient and useful in terms of real-time multiple objects detecting and tracking.

• Journal of Broadcast Engineering
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• v.11 no.4 s.33
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• pp.407-419
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• 2006

In this paper, an adaptive illumination change compensation method is proposed for multi-view video coding. In multi-view video, an illumination change can occur due to physically imperfect camera calibration, each different camera position and direction, and so on. These characteristics can cause a performance decrease in the multi-view video coding that uses an inter-view prediction by referring to the pictures obtained from the neighboring views. By using the proposed method, a compression ratio of the proposed method in the multi-view video coding is increased, and finally $0.1{\sim}0.6dB$ PSNR(Peak Signal-to-Noise Ratio) improvement was obtained compared with the case of not using the proposed method.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.105-112
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• 2011

We propose an adaptive load balancing scheme to transport real-time video streams efficiently in this paper. The playback buffer level of a video requesting client is high or low temporarily in mobile environment. This scheme attempts to allocate more network bandwidth to serve a video request with the lower buffer level preferentially. In this scheme, the amount of network bandwidth is dynamically allocated to the requesting clients according to their playback buffer levels in a distributed mobile system. In order to improve the quality of service and real-time performance of individual video playback, the proposed load balancing scheme tries to maximize the number of frames that are transported successfully to the client prior to their playback times. Fair services can also be provided to all the concurrent clients by making their playback situation more adaptive. The performance of this load balancing scheme is compared with that of other static load balancing scheme through extensive simulation experiments, resulting in the higher ratio of frames transmitted successfully within given deadlines.