(several feature kind combination) simply by mixing them all together (color + texture + shape). We present, in Figure 12 and Figure 13, the first 15 images retrieved for a query image, using respectively aggregated features and hierarchical features. In these two figures, the first image is the request image. We observe, obviously, that the retrieval accuracy of hierarchical feature model is more efficient than that of aggregated feature use. However, we demonstrate in this section that the feature aggregation is not enough efficient, if we just mix various feature kind. Indeed, each descriptor kind range is different than those of the other descriptor kinds.