对双能计算机断层扫描(CT)图像进行三维图像配准是准确获取样品内部元素分布信息的前提。针对同步辐射双能CT 成像存在的图像空间失准问题，提出了一种以互信息作为衡量双能CT 图像相似度的图像配准方法。采用部分体积(PV)插值算法计算互信息，采用遗传算法进行较优参数的搜索，并以该参数作为Powell算法搜索的起始点，结合基于Hanning 窗的部分体积插值(HPV)算法搜索得到最佳配准参数。数值模拟验证了HPV 算法的优越性，同时配准精度达到亚像素级。实验结果表明，该方法能够有效配准双能CT图像并获得三维元素分布信息。

Image registration is the premise for extracting accurate inner element distribution information of samples from dual-energy computed tomographic (CT) images. In order to solve the misalignment of dualenergy CT images in synchrotron radiation, an image registration method is proposed which uses mutual information as the standard to measure similarity of two dual-energy CT images. The partial volume (PV) interpolation algorithm is used to calculate mutual information and the genetic algorithm is used to search the initial good parameters. Then the original searching point for Powell algorithm is initialized with these parameters and the PV interpolation based on Hanning window (HPV) is combined to search the optimal registration parameters. The numerical simulation testifies the advantages of HPV algorithm and the accuracy of registration achieves subpixel. Experimental results show that the proposed method is effective for dualenergy CT image registration and acquirement of three-dimensional distribution of elements.