ABSTRACT
We describe approaches and techniques for indexing and retrieving still images from multimedia databases. We specifically emphasize content-based image retrieval (CBIR), a class of techniques where the user composes queries that specify the content of the desired images. After a brief overview of digital image formats, we analyze different approaches to content specification: in terms of low-level visual features, of objects, and of metadata. We then describe a general progressive framework that combines these approaches. We finally conclude the entry with an overview of common applications of image repositories and digital libraries, such as medical imaging, remote-sensing imaging, and data for the oil industry.
