Digital photography has not only changed the nature of photography and the photographic process, but also the manner in which we share photographs and tell stories about them. Some traditional methods, such as the family photo album or passing around piles of recently developed snapshots, are lost to us without requiring the digital photos to be printed. The current, purely digital, methods of sharing do not provide the same experience as printed photographs, and they do not provide effective face-to-face social interaction around photographs, as experienced during storytelling. Research has found that people are often dissatisfied with sharing photographs in digital form.
The recent emergence of the tabletop interface as a viable multi-user direct-touch interactive large horizontal display has provided the hardware that has the potential to improve our collocated activities such as digital photograph sharing. However, while some software to communicate with various tabletop hardware technologies exists, software aspects of tabletop user interfaces are still at an early stage and require careful consideration in order to provide an effective, multi-user immersive interface that arbitrates the social interaction between users, without the necessary computer-human interaction interfering with the social dialogue.
This thesis presents PhoTable, a social interface allowing people to effectively share, and tell stories about, recently taken, unsorted digital photographs around an interactive tabletop. In addition, the computer-arbitrated digital interaction allows PhoTable to capture the stories told, and associate them as audio metadata to the appropriate photographs. By leveraging the tabletop interface and providing a highly usable and natural interaction we can enable users to become immersed in their social interaction, telling stories about their photographs, and allow the computer interaction to occur as a side-effect of the social interaction. Correlating the computer interaction with the corresponding audio allows PhoTable to annotate an automatically created digital photo album with audible stories, which may then be archived. These stories remain useful for future sharing -- both collocated sharing and remote (e.g. via the Internet) -- and also provide a personal memento both of the event depicted in the photograph (e.g. as a reminder) and of the enjoyable photo sharing experience at the tabletop.
To provide the necessary software to realise an interface such as PhoTable, this thesis explored the development of Cruiser: an efficient, extensible and reusable software framework for developing tabletop applications. Cruiser contributes a set of programming libraries and the necessary application framework to facilitate the rapid and highly flexible development of new tabletop applications. It uses a plugin architecture that encourages code reuse, stability and easy experimentation, and leverages the dedicated computer graphics hardware and multi-core processors of modern consumer-level systems to provide a responsive and immersive interactive tabletop user interface that is agnostic to the tabletop hardware and operating platform, using efficient, native cross-platform code. Cruiser's flexibility has allowed a variety of novel interactive tabletop applications to be explored by other researchers using the framework, in addition to PhoTable.
To evaluate Cruiser and PhoTable, this thesis follows recommended practices for systems evaluation. The design rationale is framed within the above scenario and vision which we explore further, and the resulting design is critically analysed based on user studies, heuristic evaluation and a reflection on how it evolved over time. The effectiveness of Cruiser was evaluated in terms of its ability to realise PhoTable, use of it by others to explore many new tabletop applications, and an analysis of performance and resource usage. Usability, learnability and effectiveness of PhoTable was assessed on three levels: careful usability evaluations of elements of the interface; informal observations of usability when Cruiser was available to the public in several exhibitions and demonstrations; and a final evaluation of PhoTable in use for storytelling, where this had the side effect of creating a digital photo album, consisting of the photographs users interacted with on the table and associated audio annotations which PhoTable automatically extracted from the interaction.
We conclude that our approach to design has resulted in an effective framework for creating new tabletop interfaces. The parallel goal of exploring the potential for tabletop interaction as a new way to share digital photographs was realised in PhoTable. It is able to support the envisaged goal of an effective interface for telling stories about one's photos. As a serendipitous side-effect, PhoTable was effective in the automatic capture of the stories about individual photographs for future reminiscence and sharing. This work provides foundations for future work in creating new ways to interact at a tabletop and to the ways to capture personal stories around digital photographs for sharing and long-term preservation.