非亚采样Contourlet变换是在非亚采样塔型滤波器及非亚采样方向滤波器组的基础上建立起来的,它是一种移不变多方向多尺度图像表示方法。介绍了该变换的结构特点与系数分布特性,并研究了基于非亚采样Contourlet变换的图像融合算法。该算法利用非亚采样Contourlet的平移不变性以及NSCT系数特点,有效准确地提取图像边缘与细节区域,并分别在高、低频域针对不同区域采用不同的融合方法,有效挖掘了待融合图像中的有效信息。这种具有多分辨率分析和多方向滤波特点的处理方法,提高了融合后遥感图像中的信息量和清晰度,对不同分辨率不同方向上的信息进行挖掘及融合,解决了传统小波融合算法中方向数目受限的不足。通过仿真实验与传统融合方法进行比较,验证了该方法的有效性和优越性。

The nonsubsampled Contourlet transform is built upon nonsubsampled pyramids and nonsubsampled directional filter banks and provides a shift-invariant directional multi-resolution image representation. The nonsubsampled contourlet transform and its coefficients characteristics are introdued. A method for image fusion based on nonsubsampled contourlet transform is presented, which could extract the edge and detail coefficients and fuse the information in high and low resolutions efficiently. The multi-direction and multi-resolution method fully extracting the fusion information, improves the image definition and information quantity by using different fusion methods in different frequency and directions, which overcomes the directional limitation of Wavelet. By simulation experiment and comparison with other arithmetic, the validity and superiority of the method are proved.