Error Propagation In Transmission Research Articles

Efficient Adaptive Intra Refresh Error Resilience for 3D Video Communication

3D video wireless communication is being repeatedly called upon to play a greater role in the quest for economic and political stability, peace and understanding in the world. However, excessive error propagation in compressed 3D video can dramatically decrease perceived quality of experience (QoE). Recent error control strategies suggested that using adaptive intra refresh (AIR) tool is a good candidate for fulfilling quality of service (QoS) requirements for 3D video transmission over wireless networks. We propose multi-view video AIR (MVV-AIR) based on H.264/advance video coding (AVC) to mitigate transmission error propagation in a two-way communication system. With the MVV-AIR, both high active macroblocks and channel bit error rate (BER)are computed to generate MVV-AIR refresh map. The generated map is used to periodically insert a cyclic intra-refresh line macroblock to suppress spatiotemporal error propagation. Experimental results show that MVV-AIR outperforms traditional refresh scheme in error prone transmission environment with improved objective and subjective visual quality.

Efficient Adaptive Intra Refresh Error Resilience for 3D Video Communication

3D video wireless communication is being repeatedly called upon to play a greater role in the quest for economic and political stability, peace and understanding in the world. However, excessive error propagation in compressed 3D video can dramatically decrease perceived quality of experience (QoE). Recent error control strategies suggested that using adaptive intra refresh (AIR) tool is a good candidate for fulfilling quality of service (QoS) requirements for 3D video transmission over wireless networks. We propose multi-view video AIR (MVV-AIR) based on H.264/advance video coding (AVC) to mitigate transmission error propagation in a two-way communication system. With the MVV-AIR, both high active macroblocks and channel bit error rate (BER)are computed to generate MVV-AIR refresh map. The generated map is used to periodically insert a cyclic intra-refresh line macroblock to suppress spatiotemporal error propagation. Experimental results show that MVV-AIR outperforms traditional refresh scheme in error prone transmission environment with improved objective and subjective visual quality.

Robust Adaptive Intra Refresh for Multiview Video

Transmission error propagation in wireless multimedia communication systems has become a recurring problem. This persistent problem has led to grave consequences on the visual quality of the decoded video. It is against this backdrop that, we present an adaptive intra refresh (AIR) error -resilient coding tool to mitigate the effect of transmission error propagation in 3D video communications. This work utilizes periodic insertion of intra macroblocks in badly error -infected frames temporally as well as related frames in the multi view video scheme. Our objective is to maxim ize the transmission efficiency while ensuring the transmission robustness of the coded bitstream. The selection of periodic macroblocks is based on areas with high motion above a pre-set threshold. The coding modes of the macroblocks are based on the distortion expectation due to transmission errors. Extensive simulation results show significant improvement in both objective and subjective video quality at different intra refresh rates.

Robust Adaptive Intra Refresh for Multiview Video

Transmission error propagation in wireless multimedia communication systems has become a recurring problem. This persistent problem has led to grave consequences on the visual quality of the decoded video. It is against this backdrop that, we present an adaptive intra refresh (AIR) error-resilient coding tool to mitigate the effect of transmission error propagation in 3D video communications. This work utilizes periodic insertion of intra macroblocks in badly error-infected frames temporally as well as related frames in the multi view video scheme. Our objective is to maximize the transmission efficiency while ensuring the transmission robustness of the coded bitstream. The selection of periodic macroblocks is based on areas with high motion above a pre-set threshold. The coding modes of the macroblocks are based on the distortion expectation due to transmission errors. Extensive simulation results show significant improvement in both objective and subjective video quality at different intra refresh rates.

Efficient Rate–Distortion Optimal Packetization of Embedded Bitstreams Into Independent Source Packets

This paper addresses the rate-distortion (R-D) optimal packetization (RDOP) of embedded bitstreams into independent source packets, in order to limit error propagation in transmission of images over packet noisy channels. The input embedded stream is assumed to be an interleaving of K independently decodable basic streams. To form independent source packets, the set of basic streams is partitioned into N groups. The streams within each group are then interleaved to generate a source packet. Error/erasure protection may be further applied along/across source packets, to produce the channel packets to be transmitted. The RDOP problem previously formulated by Wu et at. has the goal of finding the partitioning that minimizes the distortion when all source packets are decoded. We extend the problem formulation such that to also include the minimization of the expected distortion for general transmission scenarios that may apply uneven erasure/ error protection. Further, we show that the dynamic programming (DP) algorithm of Wu et al. can be extended to solve the general RDOP problem. The main contribution of this paper is a fast divide-and-conquer algorithm (D&C) to find the globally optimal solution, under the assumption that all basic streams have convex R-D curves. Instrumental in obtaining the fast solution is our result which proves that the problem can be formulated as a series of matrix search problems in totally monotone matrices. The proposed D&C reduces the running time from O(K(2)LN) where L is the size of each packet achieved by the DP solution to O(NKL log K). Experiments on SPIHT coded images demonstrate that the speedup is significant in practice.

A novel unequal loss protection approach for scalable video streaming over wireless networks

This paper presents an adaptive unequal loss protection (ULP) scheme for robust transmission of scalable video streaming over wireless networks. By jointly exploiting the temporal dependency between frames in a group of pictures (GOP) and the quality dependency between the scalable layers in each frame, the proposed scheme adoptively assigns unequal amount of forward error correction (FEC) codes across packets to each layer and adjusts the sending rate by dynamically selecting the number of layers to transmit, according to the available network bandwidth and the packet loss rate. To prevent the video transmission error propagation, an algorithm is developed to achieve efficient FEC assignment for the base layers in a GOP in the sense of minimizing the decoder distortion. The simulation results show that the proposed adaptive ULP scheme can provide better video quality under varying network conditions and can achieve more graceful degradation as packet loss increasing and available bandwidth decreasing.

Median structures for image sequence prediction

Principles of constructing predictors are discussed and two approaches to constructing multilevel structures are presented. Simulation results on coding gain, prediction signal entropy and transmission error propagation are presented and compared to an adaptive linear predictor. The results show that median structures can be used to build predictors that give comparable performance with linear ones. Robustness to transmission errors is gained by using median methods. Also, the design methods are intuitively easy and simple. >

Channel error propagation in adaptive tv coders

DPCM coders with adaptive predictors are used and compared with nonadaptive DPCM coders for processing composite color television signals. The transmission error propagation for different predictors both adaptive and fixed is investigated. Propagation of transmission noise is dependent on the type of prediction and on the location of noise, i.e., whether in a uniform region or in an active region. By introducing leak in predictor output and/or predictor function, it is shown that error propagation can be significantly reduced. The leaky predictors not only attenuate and/or terminate the channel error propagation but also improve the predictor performance based on quantitative evaluation such as peak value and mean-square-error. In order to protect the high picture quality from error propagation, an error-correcting code is needed. Der Einsatz von DPCM-Codierverfahren mit adaptivem Prädiktor bei der Verarbeitung zusammengesetzter Videosignale wird untersucht; diese Verfahren werden mit adaptiven DPCM-Codierverfahren verglichen. Insbesondere wird für verschiedene—adaptive wie nichtadaptive—Prädiktoren die Fehlerfortpflanzung bei Übertragungsstörungen untersucht. Die Fortpflanzung rauschartiger Übertragungsstörungen hängt von der Art des Prädiktors ab; auβerdem besteht eine Abhängigkeit von der Stelle, an der das Rauschen auftritt, d.h., davon, ob das Bild an dieser Stelle wenig oder stark strukturiert ist. Wie gezeigt wird, kann die Fehlerfortpflanzung durch die Einfügung einer künstlichen Dämpfung in das Ausgangssignal des Prädiktors und/oder die zur Übertragung anstehende Prädiktionsfunktion erheblich reduziert werden. Prädiktoren dieser Art dämpfen bzw. beenden nicht nur die Fortpflanzung von Übertragungsfehlern, sie verbessern darüber hinaus auch das Verhalten des Gesamtsystems, wie sich durch quantitative Messungen mit Hilfe des Kriteriums der maximalen Abweichung oder des mittleren quadratischen Fehlers nachweisen läβt. Um die hochwertige Bildqualität vor Übertragungsfehlern zu schützen, ist allerdings ein fehlerkorrigierender Code bei der Übertragung notwendig. Les codeurs MICD avec des prédicteurs adaptatifs sont utilisés et comparés avec les codeurs non adaptatifs MICD pour traiter les signaux composites de télévision couleur. La propagation de l'erreur de transmission pour les différents prédicteurs, adaptatifs et non adaptatifs, sont investigués. La propagation du bruit de transmission est dépendant du type de prédiction et de la position du bruit, c'est-à-dire si le bruit se trouve dans une région uniforme ou une région active. Il est montré que la propagation des erreurs peuvent être réduite considérablement en introduisant une distribution à la sortie du prédicteur et/ou à la fonction de prédiction. Les prédicteurs distributifs non seulement attenuent et/ou arrètent la propagation des erreurs de voie mais améliorent aussi les performances des prédicteurs basées sur des évaluations quantitatives telles que valeur de pic et erreur quadratique moyenne. Pour protéger la haute qualité des images de la propagation d'erreur un code correcteur d'erreur est nécessaire.

Reduction of Transmission Error Propagation in Adaptively Predicted, DPCM Encoded Pictures

A new technique for reducing transmission error propagation in adaptively predicted, dpcm-encoded pictures is described. The basis for the technique is a generalization of the notion of predictor output attenuation, described by Graham, to include attenuation of the adaptive prediction junction. Simulation results are presented that show that application of the technique to Graham's codec results in significant reduction in error propagation without degradation of picture quality. The technique requires no increase in transmission rate.