Band Selection: Revisited

We have discussed a method of band selection in Chap. 4 where a specific subset of hyperspectral bands was selected from the input images based on the conditional entropy measure. We have also observed that one can achieve almost similar fusion output by using a small fraction of hyperspectral data. The idea of the output-based fusion motivates us to develop an alternate band selection method that selects a subset of bands depending upon whether the fused image obtained by inclusion of a particular band to the subset will be significantly different from the fused image obtained without inclusion of that band to the subset. In this chapter, we again discuss the band selection method, but from an output-based perspective. We would again like to select only a few specific bands to accomplish an efficient fusion of hyperspectral images without much sacrificing the quality of the fusion output. We discuss a similar information theoretic strategy for the selection of specific image bands of the hyperspectral data cube using the corresponding intermediate output of the fusion process. It should be noted that the input-based band selection scheme is independent of the fusion technique. The output-based band selection, however, makes use of the intermediate outputs of the fusion process, and thus, is very much dependent on the fusion technique employed.