The venue versatility of Conference GRETSI became a central element of the life of the community of Signal and Image processing, just like the " rendez-vous of Nice " of the first 16 conferences was, during 3 decades, the meeting point and major exchange opportunity of this community, and one of its undeniable cements.

This new nomad feature of the GRETSI fits particularly well with the mobile atmosphere of the new Information and Communication Society. It has been welcome by our community thanks to the remarkable work of the organizers of the 16th and 17th versions. The 18th edition which opens now devote all its efforts to keep abreast of this tradition of success.

The Midi-Pyrenees area is the uncontested center of the French space and aeronautical activity which, through its public and industrial actors is a constant support of research in Signal and Image processing. This support, which has been constant for several decades, has been instrumental in the existence in Toulouse of an academic and industrial research in our disciplines, recognized at the national and international levels. According to this evidence, the organization of the conference has been carried out by the French Space Agency of Toulouse (CNES), and supported by the whole of the local actors referred to above: CNES, Alcatel Space Industries, Rockwell Collins France, Airbus France, Astrium, Service Technique de la Navigation Aérienne (STNA), and the CERT-ONERA, together with Regional and General Councils, and the Town hall of Toulouse. At the national level, the Ministry for Research and Technology and the GDR-PRC Isis of CNRS brought a significant financial support.

The Program Committee, heir to the preceding conferences, has been the warranty of the continuity of the scientific requirement in the selection of innovating work which is the main feature of the GRETSI.

The topics which have been selected, by their wide opening and diversity, show the dynamism of our disciplines:

• Representations and models: Signal and image representations, Mono- and multi-dimensional models, identification Nonstationary signals , Nongaussian signals and higher-order statistics , Nonlinear systems and chaos, Fractals in signal and image , Deformable dynamic models, Cognitive models and perception
• Communication and coding: Information theory , Coding and compression: image and video, Coding and compression: speech and audio, Channel and joint source-channel coding, Turbo-coding, turbo-detection, turbo-equalization, Spread spectrum, multi-users detection, Space-time diversity, Communication systems, Cryptography, watermarking.
• Processing and analysis: Filtering and adaptive filtering, Spectrum analysis, time-frequency analysis, Wavelets, multiresolution, Array processing, Inverse problems, deconvolution, Sources separation , Restoration, reconstruction, denoising, Sequence analysis (motion, multimodal).
• Decision and interpretation: Statistical detection and estimation, Segmentation and change detection, Simulation techniques, Pattern recognition, Fusion in signal and image, Indexation, Neural networks, fuzzy techniques, non probabilistic theories.
• Hardware and software architectures: Algorithm architecture mapping, Languages and development tools, New technologies for integrated circuits, Embedded real-time systems.

The Application domains are in the stream of this diversity:

• Radar and Sonar, Speech, Music, Bio-engineering and life sciences, Physics and Geophysics, Remote Sensing and Space, Multimedia, Non-destructive testing, Monitoring , etc.

The corner stone of the success of the conference are in very first the authors of 414 submitted papers, among which 293 were selected after a 3-expert review procedure, experts belonging to a review committee of 185 members.

All deserve our warmest thanks, the former for the scientific value of their contributions, and the later for their efficient and rigorous selection work.

The members of the program and the organizing committees are the framework, the muscles and the brain of a great conference like the GRETSI: let them find here, on behalf of the whole Signal and Image Processing community the expression of our gratitude for their irreplaceable work.