Indexing images in Oracle8i

Content-based retrieval of images is the ability to retrieve images that ar e similar to a query image. Oracle8i Visual Information Retrieval provides this facility based on technology licensed from Virage, Inc. This product i s built on top of Oracle8i interMedia which enables storage, retrieval and management of images, audios and videos Images are matched using attributes such as color, texture and structure and efficient content-based retrieval is provided using indexes of an image index type. The design of the index type is based on a multi-level filtering algorithm. The filters reduce the search space so that the expensive comparison algorithm operates on a small subset of the data. Bitmap indexes are used to evaluate the first filter r esulting in a design which performs well and is scalable. The image index t ype is built using Oracle8i extensible indexing technology, allowing users to create, use, and drop instances of this index type as they would any oth er standard index. In this paper we present an overview of the product, the design of the image index type, and some performance results of our produc t.