Image mosaicing is stirring up a lot of interests in the re- search community for both its scientific significance and potential spin- off in real world applications. Being able to perform automatic image alignment in a common tonal and spatial reference can trigger a wide range of higher level image processing tasks such as panoramic image construction, scene depth computation, resolution enhancement, motion detection and tracking using non stationary camera. In this work we propose a fully automated real time on-line mosaicing algorithm able to build high quality seam-free panoramic images. Moreover, the whole approach does not exploit any a priori information regarding scene ge- ometry, acquisition device properties or feedback signals, thus resulting in a fully image based solution. Extensive experiments have been accom- plished to assess the quality of the attained mosaics by using them as the background to perform motion detection and tracking with a Pan Tilt Zoom camera.