• Journal of Information Processing Systems
• /
• 제7권1호
• /
• pp.103-110
• /
• 2011

In this paper, an adaptive motion vector smoothing scheme based on weighted vector median filtering is proposed in order to eliminate the motion outliers more effectively for improving the quality of side information in frame-based distributed video coding. We use a simple motion vector outlier reliability measure for each block in a motion compensated interpolated frame and apply weighted vector median filtering only to the blocks with unreliable motion vectors. Simulation results show that the proposed adaptive motion vector smoothing algorithm improves the quality of the side information significantly while maintaining low complexity at the encoder in frame-based distributed video coding.

• ETRI Journal
• /
• 제26권4호
• /
• pp.332-343
• /
• 2004

One of the recent and most significant technical properties can be expressed as "digital convergence," which is helping lead the technical paradigm into a ubiquitous environment. As an initial trial of realizing a ubiquitous environment, the convergence between broadcasting and telecommunication fields is now on the way, where it is required to develop a scalable video coding scheme for one-source and multi-use media. Traditional scalable video coding schemes have, however, limitations for higher stable picture quality especially on the region of interest. Therefore, this paper introduces an adaptive scanning method especially designed for a higher regional-stable picture quality under a ubiquitous video coding environment, which can improve the subjective quality of the decoded video by most-preferentially encoding, transmitting, and decoding the top-priority image information of the region of interest. Thus, the video can be more clearly visible to users. From various simulation results, the proposed scanning method in this paper can achieve an improved subjective picture quality far better than the widely used raster scan order in conventional video coding schemes, especially on the region of interest, and without a significant loss of quality in the left-over region.

• 대한임베디드공학회논문지
• /
• 제3권4호
• /
• pp.175-181
• /
• 2008

This paper describes the SVC-based media adaptation system which can adapt video contents optimally to various consumption environments in an IP-based transmission scenario. As key technologies, we will present scalable video coding, SVC-based adaptive media transmission, and SVC-based adaptation signaling technology.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
• /
• pp.133-136
• /
• 2003

In this paper, we propose a low bit-rate embedded video coding scheme with 3-D block partition in the wavelet domain. The proposed video coding scheme includes multi-level three dimensional dyadic wavelet decomposition, raster scanning within each subband, partitioning of blocks, and adaptive arithmetic entropy coding. Although the proposed video coding scheme is quite simple, it produces bit-streams with good features, including SNR scalability from the embedded nature. Experimental results demonstrate that the proposed video coding scheme is quite competitive to other good wavelet-based video coders in the literature.

• ETRI Journal
• /
• 제31권2호
• /
• pp.151-161
• /
• 2009

In this paper, we propose an adaptive multiview video coding scheme based on spatiotemporal correlation analyses using hierarchical B picture (AMVC-HBP) for the integrative encoding performances, including high compression efficiency, low complexity, fast random access, and view scalability, by integrating multiple prediction structures. We also propose an in-coding mode-switching algorithm that enables AMVC-HBP to adaptively select a better prediction structure in the encoding process without any additional complexity. Experimental results show that AMVC-HBP outperforms the previous multiview video coding scheme based on H.264/MPEG-4 AVC using the hierarchical B picture (MVC-HBP) on low complexity for 21.5%, on fast random access for about 20%, and on view scalability for 11% to 15% on average. In addition, distinct coding gain can be achieved by AMVC-HBP for dense and fast-moving sequences compared with MVC-HBP.

• 조명전기설비학회논문지
• /
• 제22권7호
• /
• pp.37-42
• /
• 2008

In this paper, a real-time multiview video coding system using fast disparity estimation is proposed. In the multiview encoder, adaptive disparity-motion estimation (DME) for an effective 3-dimensional (3D) processing are proposed. That is, by adaptively predicting the mutual correlation between stereo images in the key-frame using the proposed algorithm, the bandwidth of stereo input images can be compressed to the level of a conventional 2D image and a predicted image also can be effectively reconstructed using a reference image and adaptive disparity vectors. Also, in multiview decoder, intermediate view reconstruction (IVR) using adaptive disparity search algorithm (DSA) for real-time multiview video processing is proposed. The proposed IVR can reduce a processing time of disparity estimation by selecting adaptively disparity search range. Accordingly, the proposed multiview video coding system is able to increase the efficiency of the coding rate and improve the resolution.

• 방송공학회논문지
• /
• 제18권2호
• /
• pp.261-270
• /
• 2013

스테레오스코픽(stereoscopic) 3D 비디오 서비스는 기존 2D와의 호환성을 유지하면서 새로운 3D 비디오 서비스를 제공할 수 있다. 전송 대역이 제한된 지상파 방송의 경우 높은 부호화 효율을 갖는 스테레오스코픽 비디오 코덱이 요구된다. 따라서 기준영상은 기존 2D 비디오 서비스와의 호환성을 위해 MPEG-2로 부호화하는 반면 3D를 위한 부가영상 부호화를 위해 부호화 효율이 높은 H.264/AVC, HEVC(High Efficiency Video Coding) 등을 고려하고 있으며, 또한 부가영상을 비실시간으로 전송하는 NRT(Non-Real Time) 3D 서비스도 고려되고 있다. 본 논문에서는 NRT 3D 서비스를 위한 스테레오스코픽 비디오 부호화에 있어서, HEVC에서 고려되었던 적응루프필터(ALF: Adaptive Loop Filter)를 전/후처리 필터로 적용하는 기법을 제시한다. 특히, 부가영상의 후처리에 ALF를 적용하기 위하여 부호화 과정에 결정되는 CU(Coding Unit) 구조를 이용하는 HEVC와 달리 MVC(Multiview Video Coding)로 부호화한 부가영상의 매크로블록(MB) 부호화 모드 및 참조영상 인덱스 등의 MB 부호화 정보를 이용한 ALF 적용 기법을 제안한다. 부가 영상 부호화에 있어서 제안한 기법으로 전처리 및 후처리 과정으로 ALF를 적용함으로써 최대 약 24.9%의 비트율 감소를 확인하였다.

• 방송공학회논문지
• /
• 제13권1호
• /
• pp.119-127
• /
• 2008

Transmission of video over Internet or wireless network requires coded stream capable of adapting to dynamic network conditions instantly. To meet this requirement, various scalable video coding schemes have been developed, among which the Scalable Video Coding (SVC) extension of the H.264/AVC is the most recent one. In comparison with the scalable profiles of previous video coding standards, the SVC achieves significant improvement on coding efficiency performance. For adapting to dynamic network bandwidth, the SVC employs inter-layer switching between different temporal, spatial or/and fidelity layers, which is currently supported with instantaneous decoding refresh (IDR) access unit. However, for real-time adaptability, the SVC has to frequently employ the IDR picture, which dramatically decreases the coding efficiency. Therefore, an extension of SP picture from the AVC to the SVC for an efficient inter-layer switching is investigated and presented in this paper. Simulations regarding the adaptability to dynamic network bandwidth are implemented. Results of experiment show that the SP picture added SVC provides an average 1.2 dB PSNR enhancement over the current SVC while providing similar adaptive functionality.

• ETRI Journal
• /
• 제43권2호
• /
• pp.313-323
• /
• 2021

The Joint Video Exploration Team (JVET) has studied future video coding (FVC) technologies with a potential compression capacity that significantly exceeds that of the high-efficiency video coding (HEVC) standard. The joint exploration test model (JEM), a common platform for the exploration of FVC technologies in the JVET, employs quadtree plus binary tree block partitioning, which enhances the flexibility of coding unit partitioning. Despite significant improvement in coding efficiency for chrominance achieved by separating luminance and chrominance tree structures in I slices, this approach has intrinsic drawbacks that result in the redundancy of block partitioning data. In this paper, an adaptive tree structure correlating luminance and chrominance of single and dual trees is presented. Our proposed method resulted in an average reduction of -0.24% in the Y Bjontegaard Delta rate relative to the intracoding of JEM 6.0 common test conditions.

• ETRI Journal
• /
• 제34권5호
• /
• pp.666-673
• /
• 2012

Non-real-time delivery of stereoscopic video has been considered as a service scenario for 3DTV to overcome the limited bandwidth in the terrestrial digital television system. A hybrid codec combining MPEG-2 and H.264/AVC has been suggested for the compression of stereoscopic video for 3DTV. In this paper, we propose a stereoscopic video coding scheme using adaptive pre-/post-filters (APPF) to improve the quality of 3D video while retaining compatibility with legacy video coding standards. The APPF are applied adaptively to blocks of various sizes determined by the macroblock coding mode and reference frame index. Experiment results show that the proposed method achieves up to 24.86% bit rate savings relative to a hybrid codec of MPEG-2 and H.264/AVC including the inter-view prediction.