Integrating color and spatial information for content-based image retrieval in large image database

Color histograms are widely used for content-based image retrieval because they are trivial and effective to compute, not sensitive to size and orientation, and robustly tolerate movement of objects in the image and changes in camera viewpoint. However, a color histogram only records an image's overall color compositions and no any spatial information is included, and also retrieval precision is limited. In this paper, a color-spatial histogram, which incorporates spatial information with color compositions without sacrificing the robustness of color histograms, is proposed. The purpose is considering the representation role of color compositions and spatial information in the meantime. Each entry in a color-spatial histogram is the color frequency and corresponding position information of the virtual boundary. Experimental evidence suggests that this new color-spatial histogram outperform not only the traditional color histogram method but also the other color-spatial histogram methods for image retrieval.