Search

A zerotree image-coding scheme is introduced that effectively exploits the inter-scale self-similarities found in the octave decomposition by a wavelet transform. A zerotree is usuful for efficiently coding wavelet coefficients ; its efficiency was proved by Shapiro's EZW. In the EZW coder, wavelet coefficients are sympolized, then entropy-coded for further compression. In this paper, we analyze the symbols produced by the EZW coder and discuss the entropy for a symbol. We modify the procedure used for symbol-stream generation to produce lower entropy. First, we modify the fixed relation between a parent and children used in the EZW coder to raise the propability that a significant parent has significant children. The modified relation is flexibly modified again based on the observation that a significant coefficient is more likely to have significant coefficients in its neighborhood. The three relations are compared in terms of the number of symbols they produce.

International audience; Motivated by recent trends in technologies development related to multi-sensorial experience together with the democratization of virtual worlds MPEG started a new standard called Media Context and Control and abbreviated MPEG-V. The new standard is composed of four parts-Architecture, Control Information, Sensory Information, Avatar Information. In order to address the specific application of multi-sensorial experience, we implemented the RoSE (representation of sensory effects) framework that provides sensory effects to users by associating multimedia of various sensory devices. The framework contains four work items: SE (Sensory Effects), USP (User Sensory Preferences), SDC (Sensory Device Capabilities), and SDCom (Sensory Device Commands). These items are standardized in part 2 and part 3 of MPEG-V In this paper we review the MPEG-V activities and describe the RoSE framework.