为了更好地进行遥感图像融合，基于àtrous Contourlet变换, 提出了一种利用梯度和匹配度结合的多光谱和高分辨率图像融合新算法。该算法首先结合Contourlet变换和àtrous小波的优势，将图像进行àtrous Contourlet多分辨率分解；由于梯度反映了图像的细节信息，因此该算法在加权时，为了尽可能地提高空间分辨率，考虑高频系数对应位置系数的正负，提出了一种匹配度梯度加权算法（match degree weighted gradient algorithm，MWGA）用于对高频细节进行融合；最后用高频附加的方法得到最后的融合图像。实验表明，此算法能在获得很好的光谱质量的基础上，获得空间细节增强效果更佳的图像。

A fusion algorithm of a low resolution, multi spectral image and a high resolution image based on àtrous Contourlet transform with match degree and gradient selection is proposed. First, the resource images are decomposed àtrous Contourlet transform, which the advantages of àtrous transform and Contourlet transform. Then considering that the gradient represents the details of images, and that the positive or negative coefficients are existed in the corresponding position, for the purpose that the space resolution of the fused image is as high as possible, MWGA（match degree weighted gradient algorithm）is proposed for the fusion of high frequency details. The last, the fused image is acquired the method of high frequency addition. It is proved that the fusion results especially the space detail quality of the proposed method is better comparing the traditional methods.