An architecture for and query processing in distributed content-based image retrieval

Images are being generated at an ever increasing rate by diverse military and civilian sources. A content-based image retrieval system is required to utilize information from the image repositories effectively. Content-based retrieval is characterized by several generic query classes. With the existence of the information superhighway, image repositories are evolving in a decentralized fashion on the Internet. This necessitates network transparent distributed access in addition to the content-based retrieval capability. Images stored in low-level formats such as vector and raster are referred to as physical images. Constructing interactive responses to user queries using physical images is not practical and robust. To overcome this problem, we introduce the notion of logical features and describe various features to enable content-based query processing in a distributed environment. We describe a tool named SemCap for extracting the logical features semi-automatically, We also propose an architecture and an application level communication protocol for distributed content-based retrieval. We describe the prototype implementation of the architecture and demonstrate its versatility on two distributed image collections. (C) 1996 Academic Press Limited