Abstract: In this paper, we reflect on two observations. The first one is that sharing artifacts such as photographs is a powerful and emotionally-rich form of social interaction. The second one is that we all associate emotions to the places that we visit. For these reasons, we are interested to explore new tools for capturing the ambience of neighborhoods and cities. We are also interested to develop ways for people to share these ambiences both online and in augmented physical places. We introduce our ideas in this domain and illustrate them with two ongoing projects: AmbiGrabber and Boxes and Lenses. With these systems, our goal is to create a basic set of technologies that will allow us to build and experiment with social applications in urban environments.

1. Sharing Emotions about the Neighborhood and
through the Neighborhood
Olivier Liechti, Thomas Pham
IICT / HEIG-VD
University of Applied
Sciences of Western Switzerland
1401 Yverdon-les-Bains, Switzerland
Email: olivier.liechti@heig-vd.ch
Pitoyo Hartono
School of Information Science and Technology
Dept. of Mechanics and Information Technology
Toyota-shi, Japan
Email: hartono@sist.chukyo-u.ac.jp
Alain Lala, Florian Broennimann
Future University Hakodate
Hakodate, Japan
IICT / HEIG-VD
1401 Yverdon-les-Bains, Switzerland
Abstract—In this paper, we reflect on two observations. The
first one is that sharing artifacts such as photographs is a
powerful and emotionally-rich form of social interaction. The
second one is that we all associate emotions to the places that we
visit. For these reasons, we are interested to explore new tools for
capturing the ambience of neighborhoods and cities. We are also
interested to develop ways for people to share these ambiences
both on-line and in augmented physical places. We introduce
our ideas in this domain and illustrate them with two ongoing
projects: AmbiGrabber and Boxes and Lenses. With these systems,
our goal is to create a basic set of technologies that will allow
us to build and experiment with social applications in urban
environments.
Index Terms—Memories, emotions, affective awareness, mobile
computing, ubiquitous computing, digital photography, public
displays, augmented communities.
I. INTRODUCTION
There is something quite peculiar about Japan, which we
have repeatedly observed over time. This observation has
inspired many of the ideas presented in this paper and has
been one of the motivations for our work in this area. It
relates to the impressions that people feel when visiting urban
environments, it relates to the memories that they keep about
cities, neighborhoods and buildings. Even more interestingly,
it relates to the feelings that people have in common about
these places, even when they do not know each other.
As the authors of this paper, we have collectively spent
several years in Japan and have kept fond memories of this
country. We have met many other foreigners, who have either
traveled or lived there and thus have had opportunities to
talk about our personal experiences. Of course, a common
practice in this context is to share photographs about visited
places. We have noticed something that may seem anecdotal,
but which in our opinion reveals a very powerful idea: in
almost every photo collection related to Japan, one will find
a snapshot of a vending machine and a snapshot of a narrow
street with a messy arrangement of electric cables. At first
glance, the reality depicted in these snapshots is not aesthetic
at all. As a matter of fact, many people looking at the pictures
will find it surprising that one could even thinking about
taking such a snapshot in the first place. Nevertheless, if
the people looking at the photographs have visited Japan in
the past, they will instantly feel something and remember
positive impressions about their stay. Photographs are not
simply artifacts that capture reality. They are artifacts that have
an emotional impact on the the people who look at them. This
is of course true for pictures depicting people (think of family
portraits), but also for pictures depicting places. Some previous
work have proposed the notion of affective awareness [1] to
capture lightweight and non explicit communication patterns.
Systems that make it easier for people to share photographs are
well suited to support affective awareness. This is particularly
true if they provide mechanisms to capture the emotional
reaction of the users watching the pictures. We have previously
focused on the use of such systems in domestic settings, with
the goal to enhance communication within families. In this
paper, we expand the scope to larger and more diffuse social
networks. We look at ways to create connections between
people, based on the places they visit. We look at ways to
collect, but also to distribute and disseminate, user generated
content in augmented physical spaces. This is a vast topic
and to explore it, our approach is to develop a core set of
tools and frameworks that we will then use to support various
application scenarios. We intend to explore new forms of social
interactions grounded in physical environments, at different
scales (e.g. at the scale of a museum, at the scale of a city).
In this paper, we first go through a number of design issues,
which we believe are important for the design of urban social
applications. While we are interested to come up with original
application scenarios, we are equally interested to build and
deploy these applications in real-world settings. This approach
is reflected in some of the issues that we consider and which
are very practical. In the second part of the paper, we present
the design of two systems respectively named AmbiGrabber
and Boxes and Lenses. The first system seeks to provide
new means to capture ambiences when visiting a particular
neighborhood. The tool aims to make it easy to create and
share visual snapshots, but also audio snippets. The second
system seeks to provide a generic model for distributing digital
artifacts in augmented physical environments, as well as for
interacting with these artifacts in different types of applica-
tions. The implementation of these systems is in progress and
we intend to have demonstrators at the workshop.

2. Fig. 1. Typical street view in Tokyo: does it bring back nice memories?
II. URBAN SOCIAL APPLICATIONS
In this section, propose two definitions for what we call
urban social applications. Firstly, we argue that urban envi-
ronments provide a very interesting context to support and
stimulate interpersonal communication. Secondly, we argue
that urban environments offer opportunities to use existing
digital assets in original ways.
A. Interacting through the city
As we mentioned before, people have impressions and feel-
ings when they live, work and visit cities. Some neighborhoods
are stressful, others are boring. Some buildings are amazingly
beautiful, others are scary. Most often, the impressions felt
by people stay personal. They exist solely in their memories
and are somewhat ephemeral. But sometimes, people use these
memories as a context for social interactions. This is what
happens when people talk about the places they have visited,
what they have seen, etc. Of course, what happens in face-to-
face communication can also happen in computer-mediated
communication. Hence, we would like to propose a first
definition: a urban social application is a system that promotes
the creation of content grounded in a physical environment and
that fosters interpersonal communication around this content.
Tools that combine multimedia capture, instant and lightweight
communication, geo-location certainly fit in this category.
B. Interacting with the city
We are interested by the design of interactive systems that
connect content-centric applications to physical places. In
urban spaces, there is already an flow of information, but it is
still mostly unidirectional (think of advertisements, billboards,
speakers). Our goal is to allow city inhabitants and visitors to
interact with the environment in richer ways. Street art, such
as graffiti, is a form of urban cultural expression. We seek
to develop non-obtrusive and non-destructive ways that allow
people to personalize and decorate public places, based on
their personal digital assets. Based on this, we would like to
propose a second definition: a urban social application is a
system through which users can interact with and alter the
physical environment and which creates new forms of social
interactions.
III. DESIGN CONSIDERATIONS
A. The quasi ubiquitous network
Many ubiquitous computing applications assume the avail-
ability of a high-bandwidth, continuous and free (or at least
affordable) network connection. This is true to a certain extent,
but there are still situations where the hypothesis does not
hold. The applications that we have in mind will be appealing
to people traveling abroad. The costs currently associated with
data roaming are still prohibitive. Therefore, we believe that a
key requirement for urban social applications is to integrate

3. an offline mode (and to support periodic synchronization,
typically when users get access to WiFi hotspots).
B. Critical mass
We are interested to create new opportunities for people to
discover each other, for people to communicate by exchanging
artifacts and impressions about these artifacts. For these social
features to make sense, a critical mass of users must be
reached. This is always a challenge, and we argue that a key
design principle for urban social applications is to include a
set of features that bring value to individual users, before they
start interacting with other users.
C. Moderation
We are interested to offer ways for people to create and
share content based on the places they visit. We are interested
by scenarios where the sharing is not done exclusively on-
line, but is done in augmented physical environments. One
of the ideas that springs to mind is for a user to be able to
publish a personal photograph onto a public display (typically
using his mobile phone as a kind of remote controller). The
idea of broadcasting user generated content in public spaces
is interesting, but raises sensitive issues. In particular, it raises
the question of how to define what content is appropriate
for publication and based on this how to setup an effective
moderation process. This is not trivial, because different forces
need to be balanced. From a user experience point of view,
it is important for public interactive systems to give rapid
feedback to users. A system that allows users to send personal
photographs and that displays the photographs on a public
display after a couple of days is interesting. But it is not be
as engaging as a system that displays the photograph almost
instantly. On the other hand, a realtime moderation process
through which submitted photographs can immediately been
accepted or rejected, is only realistic for events and not for
extended period of times.
An interesting question to investigate, is how the moder-
ation process can be distributed and how responsibility can
be delegated within the community of users. Nevertheless,
the owner of the public display sometimes needs to have a
complete control on the approval process. In this case, we
argue for the decoupling of two processes. The first process
consists in submitting personal content to the system (without
the need for immediate feedback), the second process consists
in using previously approved content when interacting with the
augmented environment. This means that users both have the
possibility to contribute with their own content and to interact
with highly reactive systems. Reflecting on these ideas, we
believe that there are very different application settings, with
varying needs for moderation and access management. One
objective of Boxes and Lenses, described later, is to offer a
relatively simple set of abstractions that can be combined and
configured to accomodate these varying needs.
IV. AMBIGRABBER
The first system that we are working on is named Ambi-
Grabber. It fits in the first category of urban social applica-
tions, as described in Paragraph II-A. As its name suggests,
it is a tool that people will use to grab ambiences when
they explore cities. The tool allows people to take visual and
auditory snapshots, but also to express their current state of
mind and impressions. This last element is one of the most
interesting investigation areas.
A. System overview
AmbiGrabber consists of two main components. The first
component of the system is a mobile application, which
people use to record snapshots. It is very similar to the
camera applications that run on mobile phones. In addition
to photographs, the tool also makes it possible to record
audio snippets. We believe that recording the ambient sound
is important to capture the atmosphere of a neighborhood.
Looking at the particular case of Japan once again, hearing
the noise of a Pachinko hall or the sound of a cicada will
instantly bring back memories to people having visited Japan.
The second component of the system is a portal, allowing
users to explore the captured artifacts and to give their own
feedback. We plan to investigate original navigation methods
in the content.
B. Impromptu recordings
One of the key design requirements for AmbiGrabber is that
the capture of ambiences should be easy, quick and pleasant.
This important to entice users to use the tool regularly, hence
to drive the creation and the sharing of content. For this reason,
the user interface of AmbiGrabber is very simple. On the main
screen, push buttons allow the user to take visual, respectively
auditory snapshots. In the latter case, we have decided to limit
the maximum recording time to 20 seconds to convey the
idea that AmbiGrabber is not meant to record lengthy vocal
descriptions.
C. Network connectivity
As we explained before, the cost of data roaming is still
very expensive. Even tough it would be possible to upload
snapshots on the fly, we believe that a key requirement for the
tool is to implement an offline mode, using a local buffer and
a synchronization mechanism that can be triggered when the
user switches to a WiFi connection.
D. Gathering user impressions
In addition to the capture of snapshots, AmbiGrabber seeks
to gather the subjective feedback of the authors. Instead of
asking the user to enter a textual description, we aim to explore
original ways [2], [3] to capture a state of mind, an impression.
As shown in Figure 2, one idea is to ask the user to express
what ”color“ he currently feels. We are very interested to
analyze how such abstract annotation mechanisms would be
used.

4. Grab photo
Attach location
Grab audio
Grab both
AmbiGrabber What color do
you feel now?
What rythm do
you feel now?
Fig. 2. Mockup of the AmbiGrabber user interface: gathering user impression informally
V. BOXES AND LENSES
In Boxes and Lenses, we are interested to study interactive
systems grounded in urban environments. We are looking at
ways to capture and disseminate user generated content within
the city. Our approach is based on a simple model, with two
key abstractions. The decoupling between these abstractions
and the ability to define different types of policies makes the
model very flexible and enables the creation of very different
application scenarios.
The first abstraction, the Box, is a virtual container of digital
artifacts. A Box can be attached to a physical location. Rules
specify who has the right to put and get content from a Box.
The second abstraction, the Lens, is a software controller that
allows the user to view and interact with the content of a
Box. Lenses can for example be embodied in mobile devices
and in public displays. In the former case, the user has a
personal Lens that it can use to look at the Boxes he finds
when exploring the city. In the latter case, the content dropped
into a Box can be projected on a public space. Both Boxes
and Lenses are accessible through a RESTful API, which
makes the connectivity between the components very easy
and facilitates the creation of social applications on top of the
generic framework. This is an approach that has been used in
other application domains [2], [4], [5].
A. Looking at Boxes through Lenses
The sketches in Figure 3 illustrate a typical social applica-
tion built on top of the Boxes and Lenses framework. In this
example, we use two different types of boxes. The first type
is a personal box, that is used to store a personal archive of
artifacts. This box that is not attached to any location and is
meant to be accessed only by its own. The second type is
a public box. This box is attached to a location and has a
policy that specifies whether anybody can drop content into
the box, whether people have to physically close to the box
in order to drop content into the box, whether the box has a
limited capacity, etc. In the example, one lens is embodied into
a mobile application. Through this lens, the user can interact
both with his personal box (at the top of the screen) and with
public boxes (at the bottom of the screen). The user interface
allows the user to drag and drop pictures from one box to the
other. Of course, other lenses can be used at the same time. An
application controlling a public display [6] could very well be
connected to the public box, into which the user has dropped
content. We are thinking about different ways for the user to
connect a lens to a box. One idea is to attach QRcodes to
physical locations (bus stop, school, sports arena, etc.) and to
associate each QRCode to a specific box. Users would scan
the code in order to connect the lens to a box.
VI. CONCLUSION
In this paper, we have presented two ongoing projects,
AmbiGrabber and Boxes and Lenses. They are examples of
urban social applications, based on two definitions that we
have proposed for this concept. AmbiGrabber seeks to offer
new ways for people to capture ambiences when they explore

5. <<Lens>>
Mobile App
<<Box>>
User-owned
(personal
collection)
<<Box>>
Location-bound
The lens is configured so that the
user has access to his personal
collection of photos (there should
be a cache?)
When the user scans a QRCode, he views
the content of the associated "box"
through his "lens".
scan
The user can drag and drop a
vignette into the "Look" zone to see
the shot in a bigger format. He also
gets metadata about the photo + the
possibility to give his feedback
Look Look
info feedback
The user can drag and drop a
vignette from one box to the other.
The effect depends on the box
configuration and/or user choice (is
it a transfer, is it a swap, is it a
copy?)
After the transfer, we gather user
feedback (what does it think about
the photo he received and/or the
photo he sent)
QRCode Here...
The user can find other "boxes"
either by scanning a QRCode or by
using the current geo coordinates
(GPS)
All activities of the user
(encountering boxes, manipulating
photos, doing transfers) is recorded
and made visible on the web site. The
user can see the "travel history" of
photos, the comments, etc.
Fig. 3. Building a social application on top of Boxes and Lenses
cities. The artifacts recorded with the tool are shared and
used to stimulate interactions between people. From this point
of view, the city is conversation topic, a vector for social
interactions. Boxes and Lenses, on the other hand, proposes a
flexible platform for building applications, where photographs
and other artifacts are disseminated in augmented physical
environments. Boxes are virtual containers of artifacts. Lenses
are software controllers that allow users to interact with the
content of Boxes. The decoupling between the boxes and
the lenses, both accessible through a RESTful API, and the
ability to configure access policies for the boxes gives a lot
of flexibility to application developers. In this case, because
Boxes can be attached to locations, the city provides a physical
context for social interactions.
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