An efficient color representation for image retrieval

A compact color descriptor and an efficient indexing method for this descri ptor are presented. The target application is similarity retrieval in large image databases using color, Colors in a given region are clustered into a small number of representative colors, The feature descriptor consists of the representative colors and their percentages in the region. A similarity measure similar to the quadratic color histogram distance measure is defin ed for this descriptor. The representative colors can be indexed in the thr ee-dimensional (3-D) color space thus avoiding the high-dimensional indexin g problems: associated with the traditional color histogram. For similarity retrieval, each representative color in the query image or region is used independently to find regions containing that color. The matches from all o f the query colors are then combined to obtain the final retrievals, An eff icient indexing scheme for fast retrieval is presented. Experimental result s show that this compact descriptor is effective and compares favorably wit h the traditional color histogram in terms of overall computational complex ity.