II. RELATED WORK
A. Mobile Augmented Reality
Augmented reality (AR) at first branched from virtual
reality by overlaying a virtual computer image on top of the
real-world image [1]. In its early days, augmented reality
used head-mounted display (HMD) or hardware devices
attached with various sensors. As mobile devices have
evolved quickly in recent years, augmented reality has been
adopted in the mobile environment. Unlike the previous
generation of AR of which the focus was primarily rendering
three-dimensional graphic objects on real-time videos, AR in
the mobile environment seeks to provide enhanced user
experience by combining location data from the sensors
along with regional data retrieved from the Internet [8, 16].
Fig. 1 is a screenshot of a popular mobile AR service app,
Layar. Users can retrieve information on shops, tourist
attractions, movie theaters, etc. via this mobile AR service
app.