利用具有平移不变性的非下采样方向滤波器组（NSDFB），结合具有平移不变性的àtrous小波变换，提出了一种基于NSDFB的低分辨率多光谱图像和高分辨率全色图像的融合方法。将多光谱图像亮度、色度、饱和度（IHS）色彩空间的I分量和全色图像（PAN）分别进行àtrous小波变换，并对得到的高频系数分别进行NSDFB分解，从而得到多方向的高频信息，然后将高低频系数分别通过一定的融合算子进行融合、重构，得到I′分量，最后通过IHS逆变换得到融合图像。实验结果表明，在几种不同的客观评价标准下，该方法优于传统的IHS、主成分分析法（PCA）和小波变换方法的融合效果，能有效地改善主成分分析法（PCA）和小波变换所带来的虚假边缘和光谱扭曲现象。

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.