*4.1. Image Description*

The effectiveness of the SVM-SSHK method was validated using two hyperspectral remote sensing images of the AVIRIS Indian Pines (IP) and the ROSIS-03 University of Pavia (UP). The 145 × 145 IP image was obtained over northwestern Indiana, USA, and its ground truth data (GTD) includes 16 agricultural objects, and the 610 × 340 UP image was acquired over an urban area in Pavia, Italy, and its GTD has been produced with nine classes available. In this work, two spectral subsets of the IP and UP images with 185 bands and 103 bands, respectively, are used in our experiments, because those discarded bands locate in the absorption spectrum of water or are too noisy. Figure 3 shows the RGB color composite of the two images and GTD. Note that the class of *background* in the two HSIs was removed from further consideration in the following experiments.
