In this paper

we analyze the directional characteristics of contourlet coefficients in high frequency subbands of remote sensing images. And then we find that each coefficient in these subbands has obvious directionality. Based on this direc-tional characteristic

this paper proposes a novel image fusion algorithm for remote sensing images. First

we separately perform contourlet transform on the intensity component of the multi-spectral remote sensing image obtained by IHS transform

and the panchromatic remote sensing image. Second

we choose the low frequency coefficients of multi-spectral image’s intensity component to form the low frequency subband of target image. Subsequently

we compare the directional matching degree of the high frequency coefficients of the panchromatic image with those of the multi-spectral image’s intensity component to determine the high frequency subbands of target image. Finally

the target image is obtained by inverse contourlet transform and inverse IHS transform. Extensive experimental results show that the proposed method is superior to conventional methods in terms of entropy

joint entropy

and average gradient. It can enhance the spatial resolution of target images. Meanwhile

it well preserves the color information of multi-spectral images.