The constructure of nonsubsampled directional filter bank (NSDFB) which is a full shift invariant is introduced

and a novel image fusion scheme based on NSDFB combining àtrous wavelet transform for multispectral image(MS) and panchromatic image (PAN) is proposed. The intensity component I of MS obtained by intensity

hue and saturation (IHS) transform and the PAN are decomposed using àtrous wavelet

and the high pass-bands are decomposed in multi-directional high pass-bands respectively by NSDFB. Then the high pass-bands and low pass-bands are fused by different fusion rules

and the I′ component is reconstructed by taking inverse NSDFB decompose and inverse a-trous wavelet transform. Finally

the fusion image is obtained by inverse IHS transform of I′ and the H

S component of MS. The experimental results show that the performance of the novel algorithm is better than IHS

principal component analysis (PCA) and the traditional fusion algorithms based on wavelet transformation

and especially can effectively eliminate the spectral distortion caused by PCA and wavelet transform.