Database Reference
In-Depth Information
either by the developers of these applications or by third parties (including the
communities of users).
These applications identify the objects using Global Positioning System (GPS)
integrated into the mobile [
61
] in conjunction with other sensors such as compass,
allowing, at all times, to determine the location of the user and what he is watching.
There are two basic techniques for recognizing the object the user is looking at: the
detection of tags placed on objects to recognize, or image recognition [
40
], which
requires more computational load but results in greater flexibility to recognize
objects. With all this, the user can “see” a digital image on the screen of the mobile
phone composed by the actual image captured by the camera of the handset and the
overlapping images or content from other sources. Usually, Augmented Reality
applications have been oriented to multimedia applications, overlapping 3D objects
to captured images, but actually more applications are adding to the final image
information of interest to the user, such as the description of a painting in a
museum, of a building, monument, in videogames, etc.
There exist numerous augmented reality-based applications for mobile phones,
such as media authoring [
26
], cultural heritage [
16
], archeological fieldwork assis-
tance [
41
], e-learning [
22
], industrial applications [
66
], and location-based applica-
tions [
62
]. But many of the most used augmented reality enhanced applications in
mobile phones are related to social networks or community-built databases. As an
example, Google has recently released Google Shopper, a mobile application that
enhances the reality captured by a phone camera by adding additional information
such as description of the products captured, reviews, ratings. As another example,
Layar
4
is an augmented reality browser based on a set of information layers that can
be added to augment the reality captured by a mobile phone. Some of those layers
allow users to access user-generated content in social networks such as YouTube,
Twitter, FourSquare, or UnLike.
11.5.2 Mobile Phones as Databases
There has been an extensive research on mobile databases [
9
], addressing several
possible situations (see Figs.
11.4
and
11.5
):
l
Mobile client-fixed host. This is the most typical mobile application involving
databases and where most research has been conducted. Examples involve
traveling employees accessing corporate databases [
14
], mobile users accessing
personal data such as their bank accounts [
49
] or agenda, and servers broadcasting
information (weather, traffic, etc.) [
15
,
46
] to a large set of users or specific
mobile applications for accessing social networks such as Twitter or Facebook
[
17
].
4
http://www.layar.com
Search WWH ::
Custom Search