NATURAL INTERACTION AT WORK

T. M. Alisi MICC

Univ. of Florence Florence, Italy

alisi@micc.unifi.it

G. D’Amico MICC

Univ. of Florence Florence, Italy

damico@dsi.unifi.it

A. Del Bimbo MICC

Univ. of Florence Florence, Italy

delbimbo@dsi.unifi.it A. Ferracani

MICC Univ. of Florence

Florence, Italy andrea.ferracani@unifi.it

L. Landucci MICC

Univ. of Florence Florence, Italy

lea.landucci@gmail.com

N. Torpei MICC

Univ. of Florence Florence, Italy

nicola.torpei@unifi.it

This paper presents the media interaction systems implemented at the Mont'Alfonso Fortress, close to Castelnuovo Garfagnana (Lucca). The stronghold was built at the end of the 16th century and after being abandoned for decades it was recently submitted to a complete restoration. A multimedia environment, made of large projections, was developed in one of the buildings inside the fortress. Users can interact with natural body gestures: the multimedia contents of two tables are driven by user's hands, while projections on walls and floor are activated by motion detection. All the sensing is made using near-IR cameras. INTRODUCTION

The fortress of Mont'Alfonso in Castelnuovo Garfagnana is a cultural property of the Province of Lucca, purchased in 1980, in conditions of semi-abandonment. It was built between 1579 and 1586 on a project by Marc'Antonio Pasi from Carpi, as a last defensive stronghold of the Duchy of Ferrara to guard the border with the territory near Lucca. In 2000 the preliminary studies for the restoration of the Mont'Alfonso complex begun: named ‘Masterplan’, the plan was approved in 2001 for the urban and cultural revival of the fortress and the territory of Garfagnana and included the project of an interactive system that has to inform visitors about all the contents related to the fortress history, its restoration and the naturalistic environment surrounding the fortress itself. INTERACTIVE SYSTEMS AND SENSING ARCHITECTURE

The natural interactive environment installed at the Mont’Alfonso Fortress is composed of two systems: a system for interactive walls/floor and a system for interactive tables. Computer vision modules drive both systems. Users can interact with these systems through gestures and simple body motion, according to the Natural Human-Computer Interaction principle. Interactive Walls/Floor

Two large interactive walls are located in two opposite corners of the multimedia room. A floor projection welcomes visitors entering the room. Three ceiling mounted video projectors are used to display contents on the walls’ surface and floor. Ceiling mounted cameras provide video input for each of the motion detection modules. Computer vision modules trigger each video content in the video-streaming server; all the video projectors are connected to this server. The computer vision module analyzes the

motion inside the room and understands which part of the beheld zone is triggered. The system thus sends a play command to the video server, choosing the projection that has to be activated.

Interactive Tables

The Media Integration and Communication Center unveiled his natural interaction bookshop inside Palazzo Medici Riccardi in Florence during 2008. The Mont’Alfonso interactive tables represent a technology and design enhancement. A more compact design has been studied to fit the multimedia environment of Mont’Alfonso Fortress, designed to be easy to use, especially for children. The sensing architecture is made of a camera that captures screen surface from behind the table: hand gestures are easily detected thanks to the infrared diffuse illumination. This setup is also simple to implement because of the use of infrared illumination parallel to the table’s surface instead of the FTIR setup [HAN2005]. The sensing module inside the table exploit simple computer vision techniques: for each frame of video (captured at 30fps at a resolution of 320x240 pixels) just simple image processing operations are performed. The sequence adopted is made of: background subtraction, luminance threshold, noise removal (erode and dilate) then the processed image is finally connected to a components analysis module. The processed information is translated in a TCP packet describing blob positions and tracking, then sent to the interface so as to perform interaction commands and feedback. All the communication between the sensing module and the interface is made using Open Sound Control protocol.

NATURAL HUMAN-COMPUTER INTERACTION

As said, the computer vision modules send information to interfaces and triggers with the goal of creating an interactive environment comfortable for users: for this reason, the aim of Natural Human-Computer Interaction (NHCI) research is to create new interactive frameworks that integrate human language and behavior into tech applications, focusing on the way people live, work, play and interact with each other. Such frameworks have to be easy to use, intuitive, entertaining and non-intrusive. The design of natural interaction

systems is focused on recognizing innate and instinctive human expressions in relation to some object, and return the user a corresponding feedback that has the characteristics of being both expected and inspiring. The techniques proposed to perform such recognition are often referred as multi-modal interaction, focusing on how machines can understand commands coming from different channels of human communication [1].

Natural Interaction system can be modelled as the sum of different modules: the sensing subsystem, which gathers sensor data about user expressions and behaviour, and the presentation module, which realizes the dialogue with the user, orchestrating the output of different kind of actuators (graphics display, audio, haptics). All of the technology and the intelligence are built inside the digital artefacts and the user is not asked to use external devices, wear anything, or learn any commands or procedure. An interesting challenge for NHCI is therefore to make systems self-explanatory by working on their ‘affordance’ and introducing simple and intuitive interaction languages. The human expressions that can be utilized are those considered innate, meaning that they don’t have to be learned. This includes vocal expressions and all the gestures used by humans to explore the nearby space or the immediate surroundings with their bodies, like: touching, pointing and stepping into zones. These direct actions express a clear sign of interest and necessitate of a sudden reaction from the system.

Museums and exhibitions are often just a collection of objects, standing deaf in front of visitors. In many cases, objects are accompanied by textual descriptions, usually too short or long to be useful for the visitor. In the last decade, progress in multimedia has allowed for new, experimental forms of communication (using computer technologies) in public spaces [2]. With our system we try to make the fruition of information intuitive and attractive. We exploit computer vision analysis in order to recognize and analyze user’s behaviors: bare hand gestures on interactive tabletops and body motion close to interactive walls. Users can interact with an interactive tabletop just by using their hands for touching, pointing and selecting digital contents (videos and pictures). Similarly, when users approach to an Interactive wall, the system makes it react through the activation of multimedia contents.

USER INTERFACES The interfaces developed aim to show the contents of the database filled with information regarding the restoration of the fortress and its neighbourhood. The two systems are: an interface for an interactive table and an application of interactive video projection, both located in the multimedia room of the Villino Liberty within the fortress. Interactive Tables The interface for the interactive table was developed in Actionscript 3.0 using Adobe Flash CS3. It looks like a carousel of multimedia cards that illustrate and summarize the contents of the database available at the Mediateca of the fortress. A simple and usable interface design was chosen, so that the user can navigate easily between content, and can easily find the information he needs, without the necessity to ask too many questions on the operations of the interface. The focus is on the user, with his needs and his capabilities.

On the table there are thirteen cards of content and an active area for the language choice (Italian and English). The user can scroll through the cards and rotate the carousel in either direction, depending on the area of the screen where he puts his hand: each card will rotate inside the carousel along with the others towards the centre of the table, taking the leading position. The user can choose whether to select the card in the foreground, holding the hand above for a short period of time, or choose a different card to make the rotation start again. If the user chooses the centre card, it enlarges and approaches to be found. The cards are divided into two main types: cards with audio and video contributions, and cards containing a picture gallery. The tabs are closed automatically at the end of the consultation of their content (end of the video or picture gallery), but they still respond to the will of the user, who can just touch to rearrange the carousel and continue the interaction. The interface is not designed as a multi-touch, but only reacts to a ‘stimulus’ (blob) at a time.

Interactive Walls/Floor The interactive system of video projection allows projecting the videos on two vertical displays at the corners of the multimedia room and on the floor. A video server handles requests for playback and pause of the videos. Whenever a user is taken from the cameras, the system detects his presence and starts one of the video projections. The contents available in the interactive environment have been developed by a communication and marketing agency for the recovery and revitalization of the fortress of Mont'Alfonso, undertaken by the Province of Lucca. The materials, mainly video and images, present to users, besides upgrading and restructuring of the architectural heritage of the fortress and development, within it, of teaching activities and services, the analysis and explanation of the aspects characterizing the territory of the Garfagnana, its history, and the typical products and traditions. Particular attention is given to archaeological issues, the mycology, energy resources and cartography. RESULTS The design of the systems installed in the fortress was clearly made with the intention of maximizing the User Experience. User experience design, most often abbreviated UX, but sometimes UE, is a term used to describe the overarching experience a person has as a result of their interactions with a particular product or service, its delivery, and related artefacts, according to their design. As with its related term, User Interface Design, prefixing "User" associates it primarily (though not exclusively) with digital media, especially interactive software. The system is currently up and running at the fortress, and the inauguration is forthcoming at the time this paper is written. Only time and usage will confirm that all the premises of the project were-well formed and the system is truly an interactive natural experience.

As a measurable result, the multimedia room at the fortress is actually an interactive environment developed with the effort of different partners: MICC – University of Florence for the interactive systems, Studi Uniti – Firenze for the communication project, Provincia di Lucca for the funding and location and many others for all the content shown in the multimedia installations. The installed systems clearly show the hard work of integration between different skills and competences with the common goal of realizing a project that is both a system thought for people interacting with multimedia systems and an effective tool for the strengthening of the local governance. The system shows how public investments, through the realization of a space thought for people and filled with state of the art technology and contents, can reduce the gap between people and institutions.

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