Named Entity Recognition for User-Generated Tags

Content Based Multimedia Retrieval on nontextual documents is often constrained by available metadata. User-generated tags constitute an important source of information about a resource. To enable search scenarios exceeding traditional text-based search, such as exploratory and semantic search, this textual information must be complemented with semantic entities. Due to tag ambiguities and creative neologisms automatic semantic annotation based on user tags represents a major challenge. In this work, we show how to adopt context information and ontological knowledge to automatically assign semantic entities to user-generated tags for video data. Thus, a sophisticated semantic search on semantic entities is enabled. The algorithm combines co-occurence and link graph analysis using Linked Data. Also, a definition of context reliability in audio-visual content is described.