This project describes a vision based approach which allows a user to immersively navigate a real cultural environment through a lightweight web based system for the interactive walk-through and browsing of an ordered sequence of spherical panoramas.
A spherical panoramic image is created by warping the radially undistorted perspective images onto a unit sphere assuming one virtual optical center in which the user is supposed to watch at the panorama. Navigation within a single panorama is provided by two main actions: dragging and zooming; navigation among different panoramas is performed through a smooth transition with the replacement of the panoramic texture.
In order to support the navigation between panoramas the interaction design model uses a metaphor based on the zooming action of the user: the transition takes place only when the current zoom level exceeds a particular threshold. In order to minimise the gap in the transition between the two scenes, we studied and developed an algorithm that performs sub-scene matching.
The application can be configured in order to show interactive hotspots in the virtual walkthrough. Each hotspot can be activated by users and it provides several multimedia additional material about specific POIs. Hotspots are constituted by four graphic icons arranged in a circular menu. Each item represents one of the following multimedia categories: 1) gallery of images/videos, 2) PDF, 3) 3D object, 4) Indoor panorama (blue icon).
The research was conducted as part of a project developed by Andrea Ferracani and Pietro Pala in collaboration with F.A.S.T S.R.L. (Fine Art Science and Technology), which provided all the multimedia material, and funded by Regione Toscana.
The project will be presented at the 2015 IEEE International Conference on Multimedia and Expo (ICME 2015) in the Demo Session.