“…Techniques and algorithms that can extract ''visual features'' from images are crucial in supporting content-based retrieval. Color histogram techniques have been widely used (Brunelli and Mich, 2001;Cinque et al, 2001;Gong et al, 1994;Lu et al, 1994;McDonald et al, 2001;Mehtre et al, 1995;Ng et al, 1995;Niblack et al, 1993;Phanendra Babu et al, 1995;Rickman and Stonham, 1996;Sawhney and Hafner, 1994;Stricker and Orengo, 1995;Swain and Ballard, 1991;Vellaikal and Kuo, 1995;Yoo et al, 2002). Essentially, color histogram is used to represent the color distribution of an image.…”