Fusion of multispectral and panchromatic images using improved IHS and PCA mergers based on wavelet decomposition

Abstract

Abstract-Since Chavez proposed the highpass filtering procedure to fuse multispectral and panchromatic images, several fusion methods have been developed based on the same principle: to extract from the panchromatic image spatial detail information to later inject it into the multispectral one. In this paper, we present new fusion alternatives based on the same concept, using the multiresolution wavelet decomposition to execute the detail extraction phase and the intensity-hue-saturation (IHS) and principal component analysis (PCA) procedures to inject the spatial detail of the panchromatic image into the multispectral one. The multiresolution wavelet decomposition has been performed using both decimated and undecimated algorithms and the resulting merged images compared both spectral and spatially. These fusion methods, as well as standard IHS-, PCA-, and wavelet-based methods have been used to merge Systeme Pour l'Observation de la Terre (SPOT) 4 XI and SPOT 4 M images with a ratio 4 : 1. We have estimated the validity of each fusion method by analyzing, visually and quantitatively, the quality of the resulting fused images. The methodological approaches proposed in this paper result in merged images with improved quality with respect to those obtained by standard IHS, PCA, and standard wavelet-based fusion methods. For both proposed fusion methods, better results are obtained when an undecimated algorithm is used to perform the multiresolution wavelet decomposition.Index Terms-Decimated wavelet transform, intensity-hue-saturation (IHS) transform, image-fusion, multiresolution analysis, principal component analysis (PCA), undecimated wavelet transform.

Quality assessment by region in spot images fused by means dual-tree complex wavelet transform

“…Four approaches were used for the injection of PAN image details into the MS image, with the aim of minimize the degradation of the spectral information from original multi-spectral image: IHS (standard IHS merger Gonzalez-Audicana et al, 2004), DT-B (DT-CWT basic model Ioannidou and Karathanassi, 2007), DT-HM (DT-B with previous histogram matching between PAN and each of the MS bands), DT-MI (proposed method defining an injection model). Regarding spatial quality of the fused images, the list from best to worst is as follows: DT-MI, DT-B, DT-HM and IHS.…”

“…In the third category, scale-space fusion algorithms have been found to be promising and their results can be used for quantitative studies of multi-spectral properties (Gonzalez-Audicana et al, 2004). Indeed, image fusion methods based on injecting high frequency components taken from the PAN band into MS resampled bands have shown a superior ability to translate the spectral information from MS image to the new fused bands (Wang et al, 2005), i.e.…”

“…Indeed, image fusion methods based on injecting high frequency components taken from the PAN band into MS resampled bands have shown a superior ability to translate the spectral information from MS image to the new fused bands (Wang et al, 2005), i.e. introducing minimal spectral distortions, as in the following cases: discrete wavelet transform (DWT) (Garguet-Duport et al, 1996), Laplace pyramids (Wang et al, 2005), AWT (a trous wavelet transform) (Gonzalez-Audicana et al, 2004), among others. Therefore, multi-resolution analysis (MRA) has been recognized as one of the most efficient tools for the implementation of image fusion in different spatial resolution images.…”

Improving MODIS Spatial Resolution for Snow Mapping Using Wavelet Fusion and ARSIS Concept

“…The HR band (e.g., panchromatic) is then used as a substitute for I or PC1 before applying the inverse transformation. These methods are adequate when the HR band is highly correlated with I or PC1 [6]. Consequently, their application should be limited to sensors designed with a panchromatic canal that overlaps the whole spectral range of all the MS bands used in the three-band composite.…”

Quality Assessment of Fused Image of Modis and Palsar

“…However, images fused by wavelets have much less spatial information than those fused by the intensity-hue-saturation, Brovey transform, principal component analysis [17,18]. For Land cover enhancement, the spatial information of a fused image is just as important as the spectral information.…”