This paper reports on the design and implementation of BeThereNow, a public interactive information system where users are depicted immersed in various sceneries. The work is focused on the domain of info-tainment in public spaces using large displays and aims on short-time usage. The implemented system employs a mixed reality application through which users are informed about different sceneries and also create personalized digital postcards. This process is accomplished using computer vision algorithms in order to depict users and objects, while removing the background of the scene. Finally, the lessons learned from the long-term deployment of the system out-in-the-wild are presented, providing an insight on the users’ actions and reactions and feedback on future research directions.

This work regards fingertip contact detection and localization upon planar surfaces to provide interactivity in augmented displays implemented upon these surfaces, by projector-camera systems. In contrast to the widely employed approach where user hands are observed from above, lateral camera placement avails increased sensitivity to touch detection. An algorithmic approach for the treatment of the laterally acquired visual input is proposed and is comparatively evaluated against the conventional.

Today, many forms of art are influenced by the emergence of interactive technologies, including the mixing of physical media with digital technology for forming new hybrid works of art and the usage of mobile phones to create art projected on public spaces. Many artists and painters use digital technology to augment their work technically and creatively. In the same context many believe that the time of transition from traditional analogue art to postmodern digital art, that is, to an art grounded in codes rather than images has arrived. The research work described in this paper contributes towards supporting, through the use of Ambient Intelligence technologies, traditional painters’ creativity, as well as methods and techniques of art masters. The paper presents the design and implementation of an intelligent environment and its software infrastructure, to form a digitally augmented Art Workshop. Its practical exploitation was conducted in an Ambient Intelligence (AmI) simulation space and four feasibility studies were conducted. In each of these studies an oil painting was created following an alternative, yet accredited by artists, approach.

Model-driven engineering entails various modeling, abstraction and specialization levels for user-interface development. We focus on model-driven tools generating user-interface code, either entire or partial, providing a tangible basis for programmers to introduce custom refinements and extensions. The latter introduces two maintenance issues: (i) once the generated code is modified the source-to-model extraction path, if supported, is broken; and (ii) if the model is updated, code regeneration overwrites custom changes. To address these issues we proposed an alternative path: (i) instead of directly generating code, the model driven tool generates source fragments in the form of abstract syntax trees (ASTs) as XML files; (ii) the application deploys compile-time metaprogramming to manipulate, generate and insert code on-demand from such ASTs, using calls similar to macro invocations. The latter leads to improved separation of concerns: (a) the application programmer controls when and where interface source is generated and integrated in the application source; and (b) interface regeneration overwrites no source code as it only produces ASTs that are manipulated (input) via generator macros.

Presently it is very hard (or even impossible) to allow multiple players with highly diverse characteristics (including age, skills, and preferences) to collaboratively share and play a single jigsaw puzzle. Towards this end, the work presented in this paper aims to expand the capabilities of digital jigsaw puzzles in 3 directions: (a) multiplayability by a large number of players; (b) accessibility by people with handmotor and visual impairments; and (c) concurrent playability by people with highly diverse characteristics. In this context, we present an electronic puzzle game which supports single player as well as distributed multiplayer sessions by people with diverse characteristics. The paper introduces the background against which the work is based and describes the key design features of the resulting game's user interface and gameplay.

Body-based interaction constitutes a very intuitive way for humans to communicate with their environment but also among themselves. Nowadays, various technological solutions allow for fast and robust, noninstrumented body tracking at various levels of granularity and sophistication. This chapter studies three distinct cases showcasing different representative approaches of employing body-based interaction for the creation of public systems, in two application domains: culture and marketing. The first case is a room-sized exhibit at an archaeological museum, where multiple visitors concurrently interact with a large wall projection through their position in space, as well as through the path they follow. The second example is an ‘‘advergame’’ used as a means of enhancing the outdoor advertising campaign of a food company. In this case, players interact with the wall-projected game world through a virtual, two-dimensional shadow of their body. Finally, the third case presents a public system for exploring timelines in both two and three dimensions that supports detailed body tracking in combination with single-hand, two-hands, and leg gestures. Design considerations are provided for each case, including related benefits and shortcomings. Additionally, findings stemming from user-based evaluations and field observations on the actual use of these systems are presented, along with pointers to potential improvements and upcoming challenges.

A recognition method for simple gestures is proposed and evaluated. Such gestures are of interest as they are the primitive elements of more complex gestures utilized in natural communication and human computer interaction. The input to the recognition method is obtained from a head tracker that is based on images acquired from a depth camera. Candidate gestures are detected within continuous head motion and recognized, acknowledging that head pose estimates might be inaccurate. The proposed method is evaluated within the context of human-computer dialog.The reported results show that the proposed approach yields competitive recognition results to state of-the-art approaches.