Image retrieval based on 2-D histogram of fractal parameters

An image can be characterized by its fractal parameters, and hence, the fractal parameters can be used as the image signature to retrieve the images. In this paper, based on the principle that fractal transform is completely determined by luminance offset and contrast scaling, we first propose histogram of luminance offset as a statistical index, and we further propose three composite indices by combining individual histograms to enhance retrieval rate and reduce computational complexity. Experimental results on a database of 416 texture images indicate that the proposed indices significantly improve the retrieval rate, compared to other retrieval methods.