Dominant color extraction in DCT domain

An algorithm of dominant color extraction in DCT domain is described in this paper, which proposes an efficient and fast method to extract the dominant color feature from the compressed bit streams. As a part of the algorithm, a method for automatic determination of threshold is also proposed. The proposed algorithm is based on JPEG standard and some statistical parameters of DCT coefficients. Experimental results show that the proposed algorithm is effective and fast in dominant color extraction, which is also benchmarked by the existing MPEG-7 descriptors in pixel domain. A target application is similar retrieval in compressed image database or internet via this proposed algorithm.