With the growth of mobile devices and associated techonologies, creativity is the only limitation to develop interesting applications. Mobille Tagging is also a concept that’s already implemented in Japan and would certainly succeed all over the world, as already happens throughout European countries like Switzerland or Germany. In such context, MusIM is a mobile application meant to be used in museums, allowing users to browse through information regarding displayed objects. In order to achieve that, the visitor photographs an identification symbol (datamatrix code) associated to an object. Immediatly after the image decoding process, the information is shown on the mobile device.

1. MusIM: Mobile Object Browsing for Museums
José André Coelho Teixeira Marta Lopes Figueiredo
Departamento de Engenharia Informática, Faculdade de
Ciências e Tecnologia, Universidade de Coimbra
coelho@student.dei.uc.pt, martal@student.dei.uc.pt
Abstract:
With the growth of mobile devices and associated techonologies, creativity is the only limitation to
develop interesting applications. Mobille Tagging is also a concept that’s already implemented in Japan and
would certainly succeed all over the world, as already happens throughout European countries like
Switzerland or Germany. In such context, MusIM is a mobile application meant to be used in museums,
allowing users to browse through information regarding displayed objects. In order to achieve that, the visitor
photographs an identification symbol (datamatrix code) associated to an object. Immediatly after the image
decoding process, the information is shown on the mobile device.
Keywords: Ubiquitous Systems, Mobile Tagging, Mobile Devices, DataMatrix Barcode
Introduction Developing this application required a wide
initial analysis on the identification symbols
When visiting museums, exhibitions or similar available. Therefore, this paper relies on the
events, having detailed information about a study of different code types and related existing
specific item can become very useful at some works. After that, the application architecture
point. MusIM was developed to fulfill such and functionality will be presented. Finally,
need, allowing users to obtain information in a conclusions and some future work ideas will be
very simple way, just by taking a picture of a shared.
symbol associated to an item. Information
regarding that item comprises author name, Barcodes
style, date of creation and other details. There is
also the possibility of browsing through items In a general way, these symbols are images that
belonging to the same author or that share the combine black and white color, creating high
same style. Author and style details are available and low reflections that allow the conversion of
as well. To complement these features, visitors the information into binary code (0s and 1s).
can vote or comment an item being also This information can be encoded in several
possible to retrieve its location on the museum shapes such as vertical lines, points or squares
floor plan. Using votes and comments left by for example. These codes are usually decoded
visitors and the number of requests per item, with laser or optical scanners, allowing easy and
statistical information can be created and quick object identification.
become available to the exhibition organizers.

2. There are three barcode types: numeric, two perpendicular lines of ones. These can be
alphanumeric and two dimensional. As the name found on the left and bottom margins and are
points, numeric codes only use numbers in their used to align the code so that it's not necessary
character set, while alphanumeric can use both to read the code from any particular angle.
letters and numbers. Both numeric and There are also the syncs, two lines positioned
alphanumeric codes encode their information in at the most right and top margins which are
vertical lines. On the other hand, a 2D barcode made of alternated black and white cells. Syncs
provides a lot more flexibility, encoding more are used to correctly sample the cells. If the
information on smaller physical space. These matrix dimension grows, more finder patterns and
symbols also use highly qualified error syncs are added up to 8 both vertically and
correction algorithms, so that even partially horizontally. Besides all, datamatrix codes use
damaged symbols can be correctly decoded. error correction algorithms such as Reed-Solomon
while encoding data, allowing the encoded
Barcodes have been present in our lives for information to be correctly extracted from up to
a long time, but now, a new era has arrived, an 60% of partially damaged codes.
era where these are not just used to label All these characteristics combined
product prices. Barcodes are now used as small together make this code significantly fault
databases, containing all the information that tolerant during the decoding process. This was
needs to travel with the objects. the main reason why datamatrix was chosen for
this project.
Datamatrix Mobile Tagging
A Datamatrix is a two dimensional barcode Mobile Tagging is such a recent concept, that its
consisting of an even vertical and horizontal definition is not yet clear. The idea behind such
number of black and white cells, arranged in a concept relies over the connection between the
square or rectangular pattern. Each of those physical/real world to the digital world through
cells represent a bit, white for 0 and black for 1, the use of special symbols.
and all together encode either raw or text data.
Fig. 2 – QR-Code
Fig. 1 - Datamatrix codes These are just simple barcodes (typically 2D),
being QR-Code the most used one. Its practical
application is only limited by human creativity.
These codes can store up to 2 kilobytes and Japan has been the pioneer country on the use
depending on how much information is stored, of these symbols, and one can see its application
the symbol dimension may vary from 8×8 to at the least expected places. Places like train
144×144. In order to achieve a good alignment stations, outdoors, bus stops, sculptures or
and to correctly sample the cells, there are some others contain associated symbols spread all
special characteristics needed such as finder over. Its use can also be found on web sites or
patterns, also known as handles, which consist of magazines. The concept behind consists mainly

3. on getting detailed information over something.
For example, just by taking a picture at a certain
outdoor, one can add to its mobile device
"favorites" the address of the website of the
promoted product. The same happens to
sculptures or other public objects, so that
tourists can obtain more information, the same
as with MusIM. In magazines or newspapers it is
also used to complement publicity.
One curious application for these symbols
was found in a case where a car had a stick with
a barcode containing an encoded URL to the
well known auction website eBay, where it was Fig.4 – Client main menu and object info screens
for sale.
Regarding the server, there are several
Application distinct services running such as a database
server, and a HTTP server, which also serves
The system is divided in two sub-projects, the web services. To complete, there is also a server
server and the client side. In order for these to application that besides decoding the image sent
communicate, they need both to be connected by the client application, allows the
to the same network, using mainly Web Services administrators to manage the database contents,
to exchange data. print labels and access formatted statistical data.
Conclusions
While testing the system several challenges
appeared, specially related to the camera capture
module. Accessing the camera in devices
equipped with Windows Mobile 2003 is
challenging due to the fact that such task varies
from manufacturer to manufacturer, being
necessary to recode the camera capture module
for different devices. Despite this not being a
Fig. 3 – System Architecture problem in Windows Mobile 2005 devices, a
limitation related to the camera was also found,
The client application, after taking a picture especially particularly regarding the device's
of a datamatrix code sends it to the server so camera quality. If the quality is not good
that it can be decoded, in order to obtain the enough, the image captured may not be
object id. After receiving the corresponding id, correctly decoded, mainly due to factors such as
the client application is redirected to a URL lighting or distance to the picture. In good light
containing the information. From this moment, and distance conditions, no shadows and at
the client can also comment, vote or get the approximately 30cm (1 feet), the system works
location of the object. All these actions are correctly.
recorded in the main server database.
Once the system is designed to work inside
museums, lighting problems should not be an
issue. Besides, the number of devices with

4. integrated camera and its quality are increasing. 5. http://mobile.kaywa.com/qr-code-
For these reasons, MusIM can be considered a data-matrix
really good choice, not only for visitors, who
can access more information about what they 6. http://mobilecodes.nokia.com/
are seeing, but also for the exhibition
administrators, that receive more feedback from 7. http://www.technoriversoft.com/barco
visitors, non existing otherwise. de.html
Future work
Although the system is usable, there is always
space for improvement, especially in what
matters to the statistics functionality. Using
extra information stored in the database, a lot of
new reports could be generated in order to
support administrators to better manage the
exhibition. For instance, that information can be
used to see which areas are more visited at
certain period of the day or even how much
time is spent in each object or room.
As the system is now implemented it needs
constant connection to a server. However, it
would be interesting to be able to do all the
tasks without such constant connection,
allowing the system to be used in wider areas, as
zoos, natural parks, or others, being the data
synchronized periodically when a connection is
available. Adapting this system to Symbian OS
capable devices should also be interesting.
References
1. https://developer.berlios.de/projects/d
atamatrixdec
2. http://mobile.kaywa.com/qr-code-
data-matrix
3. http://tmenguy.free.fr/TechBlog/?p=1
39
4. http://www.barcodemobile.com/