Multi-source remote sensing image fusion based on nonsubsampled contourlet transform

The goal of multi-source remote sensing image fusion is to obtain a high-resolution multispectral image which combines the spectral characteristic of the low-resolution data with the spatial resolution of the panchromatic image. In this paper, methods using nonsubsampled contourlet transform (NSCT) for fusing multispectral low-resolution images with a more highly resolved panchromatic image are described. All the input images are decomposed firstly with NSCT. Then the decomposition coefficients on the different scale are combined using substitution or comparison rule, and the fused image is obtained by taking the corresponding inverse NSCT of the fused coefficients. The spatial and spectral effects are evaluated by qualitative and quantitative measures and the results are compared with those of existing discrete wavelet transform (DWT). The results show that the new method can keep better spatial resolution of the panchromatic images, and better spectral effect of the multispectral images. And the results give some guidance on how to control over how much spatial detail or spectral information should be retained.