This paper proposes a new image representation scheme for database indexing. The application domain is \image-based" indexing as opposed to \content-based" indexing. In other words, given a database of images and associated data, we want to search the database for a known image so as to retrieve the data associated with the image. A concrete example is to search a database of aerial images so as to retrieve the GPS coordinates of a known scene. Our representation is based on a hierarchy of color histograms and o ers a compromise between methods based on a global histogram and methods based on multiple histograms corresponding to segmented regions. Our method retains positional information better than the above schemes and naturally leads to a multi-level comparison strategywhere mismatches are quickly discarded at higher levels. Our method o ers a simple, easily implementable solution to the speci c problem of image-based indexing.