• Journal of Broadcast Engineering
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• v.25 no.5
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• pp.709-722
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• 2020

Point Cloud which is a cluster of numerous points can express 3D object beyond the 2D plane. Each point contains 3D coordinate and color data basically, reflectance or etc. additionally. Point Cloud demand research and development much higher effective compression technology. Video-based Point Cloud Compression (V-PCC) technology in development and standardization based on the established video codec. Despite its high effective compression technology, point cloud service will be limited by terminal spec and network conditions. 2D video had the same problems. To remedy this kind of problem, 2D video is using Scalable High efficiency Video Coding (SHVC), Dynamic Adaptive Streaming over HTTP (DASH) or diverse technology. This paper proposed a density scalability method using SHVC codec in V-PCC.

• The Transactions of the Korea Information Processing Society
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• v.7 no.4
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• pp.1033-1043
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• 2000

Recently as the user request on NoD (News-on-Demand) is largely increasing, there are a lot of researches to fulfill it. However, because of short life-cycle of new video data and periodical change of video data depending on anchor, it is difficult to apply the conventional video storage techniques to NOD applications directly. For this, we design and implement low-level storage manager for efficient storage and retrieval of multimedia data in NOD Services. Our low-level storage manager not only efficiently sotres video stream dat of new video itself, but also handles its index information. It provides an inverted file method for efficient text-based retrieval and an X-tree index structure for high-dimensional feature vectors. In addition, our low-level storage manager provides some application program interfaces (APIs) for storing video objects itself and index information extracted from hierarchial new video and some APIs for retrieving video objects easily by using cursors. Finally, we implement our low-level storage manager based on SHORE (Scalable Heterogeneous Object REpository) storage system by sunig a standard C++ language under UNIX operating system.

• Journal of Broadcast Engineering
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• v.12 no.6
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• pp.585-595
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• 2007

Distributed video coding is a new video coding paradigm based on Slepian-Wolf and Wyner-Ziv's information theory Distributed video coding whose decoder exploits side information transfers its computational burden from encoder to decoder, so that encoding with light computational power can be realized. RD performance is superior than that of standard video coding without motion compensation process but still has a gap with that of coding with motion compensation process. This parer introduces basic theory of distributed video coding and its structure and then shows RD performances of DVCs whose coding style is different from each other and of a DVC as a spatial scalable video coder.

• Journal of Broadcast Engineering
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• v.16 no.6
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• pp.1073-1076
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• 2011

In this paper, we propose a scalable random access scheme in SVC based DASH service that enables random access support not only for base layer of SVC but also for enhancement layers. The proposed method includes extension of segment index box ('sidx') from DASH standard, as well as new RAP Synchronization Box ('raps'). Since the proposed scheme provides random access service for movie fragments with SVC encoded video layers, adaptive scalable random access service is possible.

• Journal of Broadcast Engineering
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• v.6 no.3
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• pp.225-233
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• 2001

Real-time video communication applications over Internet should be able to support such functionality as scalability because of the unpredictable and varying channel bandwidth between server and client. To accommodatethe wide variety of channel bitrates, a new scalable coding tool, namely the Fine Granular Scalability (FGS) coding tool has been reduce the adopted In the MPEG-4 video standard. This paper presentsa new FGS algorithm with matching Pursuit that can reduce the computational complexity of ordinal matching pursuit-based algorithm. The Proposed coding algorithm can make trade-off between Picture Quality and computationalcomplexity. Our simulation result shows that the proposed algorithm can reduce the computational cumplexity up to 1/5 compared to the conventional FGS method while retaining a similar picture quality.

• Broadcasting and Media Magazine
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• v.20 no.1
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• pp.31-42
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• 2015

근래의 무선망 및 인터넷의 초고속화에 따라 다양한 멀티미디어 서비스가 활성화되고 있으며, 특히 방송 통신 융합망의 등장으로 인해 압축 부호화 기술만을 개발하던 시기와 달리 멀티미디어의 생성, 전송 및 소비 환경의 다양한 조건들에서 QoS(Quality of Service)를 보장하기 위해 비디오 부호화의 스케일러빌러티를 제공하기 위한 연구가 활발히 진행되고 있다. 본 고에서는 스케일러블 비디오 부호화의 개요에 대해 설명하고, 차세대 압축 표준인 HEVC(High Efficiency Video Coding)를 기반으로 시간적, 공간적, 화질적 스케일러빌러티를 제공하는 SHVC(Scalable HEVC)의 표준화와 이를 이용한 기술 개발 동향을 소개한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.257-260
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• 2006

In Video streaming environment, we must consider terminal and network characteristics, such as display resolution, frame rate, computational resource, network bandwidth, etc. The JVT (Joint Video Team) by ISO/IEC MPEG and ITU-TVCEG is currently standardizing Scalable Video Coding (SVC). This can represent video bitstreams in different sealable layers for flexible adaptation to terminal and network characteristics. This characteristic is very useful in video streaming applications. One fully scalable video can be extracted with specific target spatial resolution, temporal frame rate and quality level to match the requirements of terminals and networks. Besides, the extraction process is fast and consumes little computational resource, so it is possible to extract the partial video bitstream online to accommodate with changing network conditions etc. With all the advantages of SVC, we design and implement a network-adaptive SVC streaming system with an SVC extractor and a streamer to extract appropriate amounts of bitstreams to meet the required target bitrates and spatial resolutions. The proposed SVC extraction is designed to allow for flexible switching from layer to layer in SVC bitstreams online to cope with the change in network bandwidth. The extraction is made in every GOP unit. We present the implementation of our SVC streaming system with experimental results.

• Journal of the Korea Society of Computer and Information
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• v.5 no.3
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• pp.29-32
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• 2000

Layered video coding schemes allow the video information to be transmitted in multiple video bitstreams to achieve scalability. they are attractive in theory for two reasons. First, they naturally allow for heterogeneity in networks and receivers in terms of client processing capability and network bandwidth. Second, they correspond to optimal utilization of available bandwidth when several video qualify levels are desired. In this paper we propose a scalable video codec architectures with motion estimation, which is suitable for real-time audio and video communication over packet networks. The coding algorithm is compatible with ITU-T recommendation H.263+ and includes various techniques to reduce complexity. Fast motion estimation is Performed at the H.263-compatible base layer and used at higher layers, and perceptual macroblock skipping is performed at all layers before motion estimation. Error propagation from packet loss is avoided by Periodically rebuilding a valid Predictor in Intra mode at each layer.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.278-281
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• 2000

Matching pursuit algorithm is a signal expansion technique whose efficiency for motion compensated residual image has already been demonstrated in the MPEG-4 framework. However, one of the practical concerns related to applying matching pursuit algorithm to real-time scalable video coding is its massive computation required for finding dictionary elements. In this respective, this paper proposes a fast algorithm, which is composed of three sub-methods. The first method utilizes the property of symmetry in 1-D dictionary element and the second uses mathematical elimination of inner product calculation in advance, and the last one uses frequency property of 2-D dictionary. Experimental results show that our algorithm needs about 30% computational load compared to the conventional fast algorithm using separable property of 2-D gabor dictionary with negligible quality degradation.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.1359-1362
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• 2008

SVC(Scalable Video Coding)는 다양한 장치와 변화하기 쉬운 대역폭을 가지는 네트워크 환경에서 만족할 수 있는 스트리밍 환경을 제공하기 위해서 디자인되었지만, 본 논문에서는 SVC를 간단하면서도 효율적으로 채널 변경시간을 감소시킬 수 있도록 IPTV시스템에 응용하였다. 제안하는 시스템에서는 IPTV 헤드엔드와 LHR(Last Hop Router)사이의 네트워크 대역폭 일부분에 SVC 기본 계층으로 압축된 채널들을 정적 채널에 할당한다. 따라서 사용자가 정적 채널에 속하는 채널을 선택하면 짧은 네트워크 지연 시간 이내에 기본 계층을 전송 받아 동영상을 볼 수 있으며, 곧바로 향상 계층을 전송 받아 사용자는 정상 품질의 영상을 시청할 수 있다.