23
Progressive Band Selection
Both progressive spectral dimensionality process (PSDP) in Chapter 20 and progressive band dimensionality process (PBDP) in Chapter 21 are developed to prioritize spectral dimensions/bands and process spectral dimensions/bands in the context of progressive spectral dimension/band dimensionality expansion and reduction via dimensionality prioritization (DP)/band prioritization (BP). However, there is a key difference between PSDP and PBDP. In PSDP, “data compaction” is performed via a transformation of the original data space into a spectral-transformed component space where spectral components are of major interest and each spectral component is specified by a projection vector as a spectral component dimension. Such projection vectors are obtained by linearly combining all spectral band dimensions across the entire range of wavelengths. In contrast to PSDP, PBDP performs “data reduction” by retaining only those bands that are of interest and discarding the rest. As a result, there is no data processing involved in PBDP as it is in PSDP that processes the entire data cube by a transformation. This is why PSDP requires projection vectors to specify spectral components while PBDP does not, since the bands in PBDP can be considered a counterpart of projection vectors in PSDP. However, it is worth noting that projection vectors are completely different from spectral bands because the bands are acquired with individual and separate wavelengths with interband ...
