A scalable algorithm for image retrieval by color

To deal with large databases, we present a clustering based indexing technique, where the images in the database are grouped into clusters of images with similar color content using a hierarchical clustering algorithm. At search time the query image is not compared with all the images in the database, but only with a small subset. Thus the retrieval is scalable to large databases. Experiments show that this clustering based approach offers a superior response time without sacrificing the retrieval accuracy, which is crucial for large databases.