• Proceedings of the IEEK Conference
• /
• 2002.06d
• /
• pp.33-36
• /
• 2002

Multiple Description Coding(MDC) is a technique used to obtain two or more (often correlated) descriptions of a source, which are transmitted over different channels to receiver. Two descriptions of the source support two levels of reconstruction quality. When all the descriptions are received and used in the reconstruction, the source should be reconstructed with acceptable quality. In this work, we consider Multiple Description Scalar Quantizer(MDSQ) to wavelet transform domain. Conventional MDSQ schemes in wavelet domain considered description with equal weights at each sub-bands after quantization. But each sub-bands is unequal contribution to whole image quality. Therefore, we experiment the multiple description with unequal weight in each sub-bands.

• Journal of KIISE
• /
• v.43 no.2
• /
• pp.246-255
• /
• 2016

The orthogonal frequency-division multiple access (OFDMA) systems are well suited to multi-rate multicast transmission, as they allow flexible resource allocation across both frequency and time, and provide adaptive modulation and coding schemes. Unlike layered video coding, the multiple description coding (MDC) enables flexible decomposition of the raw video stream into two or more substreams. The quality of the video stream is expected to be roughly proportional to data rate sustained by the receiver. This paper describes a mathematical model of resource allocation and throughput in the multi-rate video multicast for the OFDMA wireless and mobile networks. The impact on mean opinion score (MOS), as a measurement of user-perceived quality (by employing a variety of scheduling disciplines) is discussed in terms of utility maximization and proportional fairness. We propose a pruning algorithm to ensure a minimum video quality even for a subset of users at the resource limitation, and show the optimal number of substreams and their rates can sustain.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.8
• /
• pp.3935-3949
• /
• 2017

In this paper, a novel multiple description image coding (MDC) scheme is proposed, which is based on the characteristics of the human visual model. Due to the inherent characteristics of human vision, the human eye can only perceive the change of the specific thresholds, that is, the just noticeable difference (JND) thresholds. Therefore, JND model is applied to improve MDC syetem. This paper calculates the DCT coefficients firstly, and then they are compared with the JND thresholds. The data that is less than the JND thresholds can be neglected, which will improve the coding efficiency. Compared with other existing methods, the experimental results of the proposed method are superior.

• Proceedings of the IEEK Conference
• /
• 2002.07a
• /
• pp.281-284
• /
• 2002

Error resilience for image coding is an important component of multimedia communication system. Error resilience schemes address loss recovery from the compression perspective. Multiple description coding (MDC) is one of the error resilience techniques promising for robust video transmission. It is the way to achieve tradeoff description such as scalar quantization, correlating transform and the quantized frame expansion. In this paper, we consider Multiple Description Scalar Quantization (MDSQ) to wavelet domain. Conventional MDSQ schemes considered description with equal weights in each sub-bands. But, we can see that the each sub-bands is unequal contribution to whole image quality. Therefore, we experiment the multiple design MDSQ table to make probability of zero index high, which gives high efficiency in arithmetic symbol coder. We also compare our proposed method with the conventional methods and show improved performance in terms of redundancy-rate-distortion.

• Proceedings of the Korean Information Science Society Conference
• /
• 2006.10d
• /
• pp.312-315
• /
• 2006

현재의 인터넷은 고품질의 스트리밍 서비스와 늘어나는 가입자를 모두 수용할 수 없다. 이러한 문제를 해결하기 위하여 Multi Path와 Multiple Description Coding (MDC) 를 사용하는 스트리밍 기법이 제안되었다. 그러나 MDC는 전체 네트워크에서 추가적인 대역폭 요구가 발생한다. 이 논문에서는 소스 노드에서 MDC 인코딩을 하는 것이 아니라 혼잡이 예상되는 지점에서 MDC로 트랜스코딩을 함으로써 대역폭이 낭비되는 문제를 해결한다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.9C
• /
• pp.840-848
• /
• 2007

A multiple description coding (MDC) scheme for 3-D Data is presented. First, a plane-based 3-D data is split into two descriptions, each of which has identical contribution in 3-D surface reconstruction. In order to maximize the visual quality of reconstructed 3-D data, then, plane parameters are modified according to channel error condition. Finally, these descriptions are compressed and transmitted over distinct channels. In decoder, if two descriptions are available, we reconstruct a high quality 3-D data. If only one description is transmitted, however, 3-D surface recovery scheme reduces artifacts on erroneous 3-D surface, yielding a smooth 3-D surface. Therefore, the proposed algorithm guarantees acceptable quality reconstruction of 3-D data even though one channel is totally lost.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.14 no.4
• /
• pp.1689-1703
• /
• 2020

When data is transmitted over an unreliable channel, the error of the data packet may result in serious degradation. The multiple description coding (MDC) can solve this problem and save transmission costs. In this paper, we propose a deep multiple description coding network (MDCN) to realize efficient image compression. Firstly, our network framework is based on convolutional auto-encoder (CAE), which include multiple description encoder network (MDEN) and multiple description decoder network (MDDN). Secondly, in order to obtain high-quality reconstructed images at low bit rates, the encoding network and decoding network are integrated into an end-to-end compression framework. Thirdly, the multiple description decoder network includes side decoder network and central decoder network. When the decoder receives only one of the two multiple description code streams, side decoder network is used to obtain side reconstructed image of acceptable quality. When two descriptions are received, the high quality reconstructed image is obtained. In addition, instead of quantization with additive uniform noise, and SSIM loss and distance loss combine to train multiple description encoder networks to ensure that they can share structural information. Experimental results show that the proposed framework performs better than traditional multiple description coding methods.

• Proceedings of the Korean Information Science Society Conference
• /
• 2006.06d
• /
• pp.289-291
• /
• 2006

최근 인터넷 접속 환경의 발달과 시스템 및 네트워크 성능 향상의 영향으로 단순한 정보의 전달뿐만 아니라 오디오, 비디오와 같은 미디어 콘텐츠(contents)의 정보 전달을 효율적으로 제공하는 방안이 연구되고 있다. 미디어 콘텐츠를 스트리밍 하는 것은 인터넷 트래픽의 아주 큰 부분을 차지하기 때문에 이러한 콘텐츠를 효율적으로 분산하기 위하여 우리는 P2P(Peer-to-Peer) 오버레이 네트워크를 이용한다. 본 논문은 Tapestry[1]를 미디어 콘텐츠 스트리밍 환경에 맞게 변형하며, 노드와 네트워크의 부하를 균등하게 분산시키기 위해 MDC(multiple description coding)[2]를 이용하여 하나의 콘텐트를 다중 트리에 분산한다. 제안된 메커니즘으로 사용자에게 보다 강화된 서비스를 제공한다.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.44 no.6
• /
• pp.100-110
• /
• 2007

When compressed video data is transmitted over error-prone network such as wireless channel, data is likely to be lost, so the quality of reconstructed picture is severely decreased. It is specially so in case that important information such as motion vector or macroblock mode is lost. H.264/AVC standard includes DP as error resilient technique for protecting important information from error in which data is labeled according to its relative importance. But DP technique requires a network that supports different reliabilities of transmitted data. In general, the benefits of UEP is sought by sending multiple times of same packets corresponding to important information. In this paper, we propose MDC technique based on data partitioning technique. The proposed method encodes motion vector of H.264/AVC standard into multiple parts using MDC and transmits each part as independent packet. Even if partial packet is lost, the proposed scheme can decode the compressed bitstream by using estimated motion vector with partial packets correctly transmitted, so that achieving improved performance of error concealment with minimal effect of channel error. Also in decoding process, the proposed multiple description matching increases the accuracy of estimated lost motion vector and quality of reconstructed video.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.4 no.4
• /
• pp.491-508
• /
• 2010

In peer-to-peer (P2P) on-demand streaming networks, the alleviation of server load depends on reciprocal stream sharing among peers. In general, on-demand video services enable clients to watch videos from beginning to end. As long as clients are able to buffer the initial part of the video they are watching, on-demand service can provide access to the video to the next clients who request to watch it. Therefore, the key challenge is how to keep the initial part of a video in a peer's buffer for as long as possible, and thus maximize the availability of a video for stream relay. In addition, to address the issues of delivering data on lossy network and providing scalable quality of services for clients, the adoption of multiple description coding (MDC) has been proven as a feasible resolution by much research work. In this paper, we propose a novel caching scheme for P2P on-demand streaming, called Dynamic Buffering. The proposed Dynamic Buffering relies on the feature of MDC to gradually reduce the number of cached descriptions held in a client's buffers, once the buffer is full. Preserving as many initial parts of descriptions in the buffer as possible, instead of losing them all at one time, effectively extends peers’ service time. In addition, this study proposes a description distribution balancing scheme to further improve the use of resources. Simulation experiments show that Dynamic Buffering can make efficient use of cache space, reduce server bandwidth consumption, and increase the number of peers being served.