Energy-efficient bandwidth allocation for multiuser scalable video streaming over WLAN

We consider the problem of packet scheduling for the transmission of multiple video streams over a wireless local area network (WLAN). A cross-layer optimization framework is proposed to minimize the wireless transceiver energy consumption while meeting the user required visual quality constraints. The framework relies on the IEEE 802.11 standard and on the embedded bitstream structure of the scalable video coding scheme. It integrates an application-level video quality metric as QoS constraint (instead of a communication layer quality metric) with energy consumption optimization through link layer scaling and sleeping. Both energy minimization and min-max energy optimization strategies are discussed. Simulation results demonstrate significant energy gains compared to the state-of-the-art approaches

A weighted distortion measure for vector quantization in transform domain

Dans cet article, une technique de compression des images couleurs, combinant la transformée en ondelette et la quantification vectorielle (VQ) est présentée. Les coefficients de la transformée en ondelette sont codés en utilisant un dictionnaire basé sur la fréquence et possédant une structure multirésolution. De plus, les corrélations intra et inter bandes sont exploitées grâce à la vectorisation. Une mesure de distorsion pondérée pour chaque sous-bande est utilisée dans le dictionnaire de manière à prendre en compte l'importance variable des bruits de quantification. Ainsi, les mots-codes obtenus reflètent l'importance relative des coefficients transformés, ce qui permet d'améliorer les performances du codeur

Motion-compensated generic coding of video based on a multiresolution data structure

We present a generic video codec, which is able to compress image sequences efficiently regardless of their input formats. In addition, this codec supports a wide range of bit rates, without significant changes in its main architecture. A multiresolution representation of the data is generated by a Gabor-like wavelet transform. The motion estimation is performed by a locally adaptive multigrid block-matching technique. This codec can handle both interlaced and progressive input sequences, the temporal redundancies being exploited by interframe/interfield coding. A perceptual quantization of the resulting coefficients is then performed, followed by adaptive entropy coding. Simulations using different test sequences demonstrate a reconstructed signal of good quality for a wide range of bit rates. Thereby demonstrating that this codec can perform generic coding with reduced complexity and high efficiency

Energy-Efficient Bandwidth Allocation for Multiuser Scalable Video Streaming over WLAN

<p>Abstract</p> <p>We consider the problem of packet scheduling for the transmission of multiple video streams over a wireless local area network (WLAN). A cross-layer optimization framework is proposed to minimize the wireless transceiver energy consumption while meeting the user required visual quality constraints. The framework relies on the IEEE 802.11 standard and on the embedded bitstream structure of the scalable video coding scheme. It integrates an application-level video quality metric as QoS constraint (instead of a communication layer quality metric) with energy consumption optimization through link layer scaling and sleeping. Both energy minimization and min-max energy optimization strategies are discussed. Simulation results demonstrate significant energy gains compared to the state-of-the-art approaches.</p