Geography Reference
In-Depth Information
Those attributes help to calculate distance, to find its location, to identify the user
who placed it and when it expires.
The location is a reference to the real geographical location and contains lati-
tude, longitude and altitude information. This information is stored together with
other object metadata. The recording of the position is achieved through the use of
industry standard Geographical Positioning System (GPS).
2.2 Presentation Modalities
To visualise the annotations or objects, we have developed and experimented with
two different modalities. We refer to them as map view or 2D map augmentation,
and camera view or camera augmentation.
2.2.1 2D Map Augmentation
2D map augmentation has two layers, a map view and an augmentation layer,
which can be used as a presentation layer to show where the virtual objects are in
the real world. The current user position is depicted as a dot on a map. For the map
display we use standard library support provided by the Google Android OS and a
map module. The display and management of the visual virtual artifacts is
manipulated by the system. The current orientation of the device can be reflected
by the appropriate map orientation. We use a number of overlays to manage the
complexity of the scene especially the case of multiple annotations. The pitch and
roll of the device can be used as a zoom and we are experimenting with a number
of User Interface concepts to make it easy and efficient for a user.
2.2.2 Augmented Camera View
To provide users with more immersive, contextual and a richer user experience we
have experimented with alternative user interface modalities. We provide users
with an Augmented Reality interface to the application, where virtual objects are
displayed directly on the video see-through. This approach behaves like a live
street view with an augmented layer on top of it. The camera provides a continuous
video stream in one layer and the other layer shows if there is a virtual object in the
field of view. We will provide more detail and the experimental setups of these
modalities in further sections of the chapter.
