The thesis discusses possibilities for using metadata and context information in annotating, sharing, and searching user-created content in the mobile domain. The first part of the thesis discusses metadata, ontologies, context information, and imaging. The latter part of the thesis describes a prototype system for classifying and annotating digital photographs and storing context information as metadata of the photographs in a mobile phone. Another role of the prototype system is to perform context- and ontology-based information retrieval using a mobile phone user interface.
The prototype system contains a limited RDF metadata engine and an ontology browser for mobile phones, as well as a server-side metadata and content repository. The implementation demonstrates that a part of the creation-time context, such as the location and temporal context, can be automatically gathered in a mobile phone, and stored as metadata for the content. In addition, the same parts of context information can be used for searching. The content and the metadata can be stored on a server and shared with other users. The prototype is built around a tourism scenario that works as an example of how these technologies can be used in a mobile phone.
