The International Gesture Workshop is an interdisciplinary event where researchers working on human gesture-based communication present advanced research currently inprogressandexchangeideasongestureacrossmultidisciplinaryscienti?cdisciplines. This workshop encompasses all fundamental aspects of gestural studies in the ?eld of human-computer interaction and simulation, including all multifaceted issues of m- elling, analysis and synthesis of human gesture, encompassing hand and body gestures andfacial expressions. A focusof these eventsis a sharedinterest in usinggesturein the contextofsign languageanalysis, understandingandsynthesis. Anotherstreamof int- est is the user-centric approach of considering gesture in multimodal human-computer interaction, in the framework of the integration of such interaction into the natural - vironment of users. In addition to welcoming submission of work by established - searchers, it is the tradition of the GW series of workshops to encourage submission of student work at various stages of completion, enabling a broader dissemination of ?nished or on-going novel work and the exchangeof experiences in a multidisciplinary environment. Gesture Workshop 2007 (GW 2007) was the 7th European Gesture Workshop in the GW series initiated in 1996. Since that date, the Gesture Workshops have been held roughly every second year, with fully reviewed proceedings typically published by Springer. GW 2007 was organized by ADETTI at ISCTE-Lisbon University - stitute, during May 23-25, 2007. In GW 2007, from the 53 contributions that were received, 15 high-quality full papers were accepted, along with 16 short papers and 10 posters and demos, showing on-going promising gesture research. Two brilliant keynote speakers honored the event with their presentations.

A variety of application areas can be attained in the fields of human-computer interaction for augmented and mixed reality, object tracking and gesture recognition. By combining the areas of 3D computer graphics, computer vision and programming, we have developed a fast, yet robust and accurate image feature detector and matcher to solve common problems that arise in the mentioned research areas. In this thesis, frequent computer vision and augmented reality problems related to camera calibration, object recognition/tracking, image stitching and gesture recognition, are shown to be solved in real-time using our novel feature detection and matching technique. Our method is referred to as FIRST - Fast Invariant to Rotation and Scale Transform. We have also generalized our texture tracking algorithm to a near model base tracking method, using pre-calibrated static planar structures. Our results are compared and discussed with other state of the art works in the areas of invariant feature descriptors and vision based augmented reality, both in accuracy and performance.