Figure 15

This figure represents the aircraft and piano segments in the feature plane. Since maximum three dimensions of the feature domain can be plotted, only three features of the feature vectors are shown in this figure. MO^H, D^H, and S^W represent the second central moment of coefficient vectors in H, the derivative of coefficient vectors in H, and the sparsity of base vectors in W, respectively. As it can be observed from the feature domain, the feature vectors from aircraft and piano are separate from each other.