Fusion of multispectral and radar images in the redundant wavelet domain

We propose in this paper an integration method of the radar information in multispectral images without disturbing the spectral content. The main problem is to define a fusion rule that allows to take into account the characteristics of these images. Also, the main purpose of this paper lies in defining a new fusion, rule performed in the redundant wavelet domain. This rule is based on the Mahalanobis distance applied on the wavelet coefficients. Instead of comparing coefficient-to-coefficient, the distance-to-distance comparison is performed. In this case, the selected coefficient in the fused image will be the one that presents the large distance. This approach is applied to fusing the infrared band of SPOT with, respectively, RADARSAT and ERS images. The results show that spectral information is well preserved and there is a better information on the texture and the area roughness.