Semisupervised Affinity Propagation Based on Normalized Trivariable Mutual Information for Hyperspectral Band Selection

The high dimensionality of hyperspectral images brings a heavy burden for image processing. Band selection is a common technique for dimensionality reduction. Since the labels of hyperspectral images are difficult to collect, a new semisupervised band selection method based on affinity propagation (AP) is proposed. AP, an exemplar-based clustering method, is famous due to fast execution time and low reconstruction error. For band selection, AP involves two key issues: band correlation and band preference. In this paper, a new normalized trivariable mutual information (normalized TMI, NTMI) is devised to measure band correlation for classification. NTMI considers not only band redundancy but also band synergy, and overcomes the sensitivity of TMI to the discriminative abilities of bands. Band preference is defined by the discriminative ability and informative amount of each band. Since the clustering methods are easily disturbed by noisy bands, a new statistical-based method for band correlation and band preference is devised. It can automatically remove noisy bands beforehand by exploiting the continuity property of bands. Finally, the proposed method can select highly discriminative and informative bands, and remove highly redundant bands. Experimental results on hyperspectral images demonstrate the effectiveness of the proposed semisupervised band selection method.