Abstract:A new algorithm is proposed to merge a high-resolution panchromatic image and a low-resolution multispectral image based on unsubsampled contourlet transform (NSCT).Firstly,the multispectral image is transformed into IHS space,and I,H,S components are obtained.Then,the original I component and panchromatic image were decomposed into multiresolution representation by using NSCT.The approximated images and detail images resulting from unsubsampled transform were fused in each level of pyramid and different direction of input resources based on certain rules.Fusion algorithms aiming at the approximated images and detail images are proposed respectively.Then the fusion image can be obtained by performing inverse unsubsampled transform and inverse IHS transform.A set of multispectral and panchromatic images were used in our test,the experimental results show that the effect of our method is more satisfactory than the usual traditional IHS method,wavelet fusion method and contourlet transform based method.