I. Introduction
Hyperspectral image (HSI) has recently received considerable attention in a variety of applications such as military target detection, mineral identification, and disaster prevention [1], [2]. In contrast to traditional panchromatic and multispectral remote-sensing images, HSI consists of hundreds of contiguous spectral bands, which are helpful to distinguishing the targets with different materials. Thanks to the high spectral resolution, HSI has shown its advantages in identifying various land-cover types or targets [3].