Fusion of multispectral and panchromatic satellite images based on contour-let transform and local average gradient

Recent studies show that wavelet-based image fusion methods provide a high spectral quality in fused satellite images. However, images fused by most wavelet-based methods have less spatial resolution because the critical downsampling is included in the wavelet transform. We propose a useful fusion method based on contourlet and local average gradient (LAG) for multispectral and panchromatic satellite images. Contourlet represents edges and texture better than wavelet. Because edges and texture are fundamental in image representation, enhancing them is an effective means of enhancing spatial resolution. Based on LAG, the proposed fusion method reduces the spectral distortion of the fused image further. Experimental results show that the proposed fusion method is able to increase the spatial resolution and reduce the spectral distortion of the fused image at the same time. © 2007 Society of Photo-Optical Instrumentation Engineers.