Quicklook(2): An integrated multimedia system

The need to retrieve visual information from large image collections is sha red by many application domains. This paper describes the main features of the multimedia information retrieval engine of Quicklook(2). Quicklook(2) a llows the user to query image and multimedia databases with the aid of samp le images, or an impromptu sketch and/or textual descriptions, and progress ively refine the system's response by indicating the relevance, or non-rele vance of the retrieved items. The major innovation of the system is its rel evance feedback mechanism that performs a statistical analysis of both the image and textual feature distributions of the retrieved items the user has judged relevant, or not relevant to identify what features the user has ta ken into account (and to what extent) in formulating this judgement, and th en weigh their influence in the overall evaluation of similarity, as well a s in the formulation of a new, single query that better expresses the user' s multimedia information needs. Another important contribution is the desig n and integration with the relevance feedback mechanism of an indexing sche me based on triangle inequality to improve retrieval efficiency. The perfor mance of the system is illustrated with examples from various application d omains and for different types of queries (target search as well as similar ity search). (C) 2001 Academic Press.