169 research outputs found
Advanced content-based semantic scene analysis and information retrieval: the SCHEMA project
No full textThe aim of the SCHEMA Network of Excellence is to bring together a critical mass of universities, research centers, industrial partners and end users, in order to design a reference system for content-based semantic scene analysis, interpretation and understanding. Relevant research areas include: content-based multimedia analysis and automatic annotation of semantic multimedia content, combined textual and multimedia information retrieval, semantic -web, MPEG-7 and MPEG-21 standards, user interfaces and human factors. In this paper, recent advances in content-based analysis, indexing and retrieval of digital media within the SCHEMA Network are presented. These advances will be integrated in the SCHEMA module-based, expandable reference system
Fast watermarking of MPEG-1/2 streams using compressed-domain perceptual embedding and a generalized correlator detector
No full textA novel technique is proposed for watermarking of MPEG-1 and MPEG-2 compressed video streams. The proposed scheme is applied directly in the domain of MPEG-1 system streams and MPEG-2 program streams (multiplexed streams). Perceptual models are used during the embedding process in order to avoid degradation of the video quality. The watermark is detected without the use of the original video sequence. A modified correlation-based detector is introduced that applies nonlinear preprocessing before correlation. Experimental evaluation demonstrates that the proposed scheme is able to withstand several common attacks. The resulting watermarking system is very fast and therefore suitable for copyright protection of compressed video
Strintzis.” Wireless transmission of images using JPEG2000
No full textA novel scheme is proposed for the transmission of JPEG2000 image streams over wireless channels. The proposed scheme exploits the block-based coding structure of the JPEG2000 streams and employs optimized product codes consisting of Turbo codes and Reed-Solomon codes in order to deal effectively with burst errors. The optimization is based on information extracted directly from the compressed JPEG2000 streams. Experimental evaluation demonstrates that the proposed scheme outperform other recent algorithms for the wireless transmission of images. 1
An animated virtual drummer
No full textWe describe a system for the automatic generation of a 3D animation of a drummer playing along with a given piece of music. The input, consisting of a sound wave, is analysed to determine which drums are struck at what moments. The Standard MIDI File format is used to store the recognised notes. From this higher-level description of the music, the animation is generated. The system is implemented in Java and uses the Java3D API for visualisation
Generating a 3D Simulation of a Car Accident from a Formal Description : the CarSim System
No full textThe problem of generating a 3D simulation of a car accident from a written description can be divided into two subtasks: the linguistic analysis and the virtual scene generation. As a means of communication between these two system parts, we designed a template formalism to represent a written accident report. The CarSim system processes template formal descriptions and creates corresponding 3D simulations. A planning component models the trajectories and temporal values of every vehicle that is involved in the accident
Natural Language Navigation Support in Virtual Reality
No full textWe describe our work on designing a natural language accessible navigation agent for a virtual reality (VR) environment. The agent is part of an agent framework, which means that it can communicate with other agents. Its navigation task consists of guiding the visitors in the environment and to answer questions about this environment (a theatre building). Visitors are invited to explore this building, ask questions and get advice from the navigation agent. A 2D map has been added to the environment so that visitors can make references to the locations and objects on this map, both in natural language and by clicking with the mouse, making it a multimodal system with cross-modality references
Fast compressed domain watermarking of MPEG multiplexed streams
No full textIn this paper, a new technique for watermarking of
MPEG compressed video streams is proposed. The watermarking scheme operates directly in the domain of MPEG multiplexed streams. Perceptual models are used during the embedding process in order to preserve the quality of the video. The watermark is embedded in the compressed domain and is detected without the use of the original video sequence. Experimental evaluation demonstrates that the proposed scheme is able to withstand a variety of attacks. The resulting watermarking system is very fast and reliable, and is suitable for copyright protection and real-time content authentication applications
A polygonal mesh partitioning algorithm based on protrusion conquest for perceptual 3D shape description
No full textInternational audienceThis paper introduces a novel partitioning algorithm for 3D polygonal meshes. The proposed approach is based on protrusion conquest which, for a given model, takes into account both the computed protrusion and the connectivity. The only constraint on the input mesh is that it must consist of one connected component. Our algorithm provides a good way to decompose the mesh into preceptually significant parts. The parts are further modeled by ellipsoids and a connectivity graph between them. This semantic representation is compliant to the perceptual shape description defined by the emergent standard MPEG-7
- …
