“…Over the years, various image fusion processes have been developed for improving spatial and spectral resolutions of RS data sets based on intensity-hue-saturation (IHS) (Choi, 2006;Karathanassi et al, 2007), color normalized (CN) Brovey (Du et al, 2007;Bovolo et al, 2010), and principal component analysis (PCA) (Shah et al, 2008). Other methods such as Gram-Schmidt (GS) (Kumar et al, 2009), CN-spectral (Vrabel et al, 2002), and Ehler (Ehler et al, 2010), high pass fusion (HPF) (Wald et al, 1997) rely on the intensity modulation. In addition, several researchers have proposed the use of wavelet transform (Shi et al, 2005;Acerbi et al, 2006) or discrete wavelet transform to extract geometric edge information from PI images.…”