基于汉宁窗函数的滤波器的设计

Design of filter based on Hanning window function

在CT图像重建中,滤波反投影是目前采用最为广泛的算法,滤波器又是滤波反投影的重要组成部分,因此滤波器的设计是滤波反投影算法的关键。滤波器的设计主要是其窗函数的选择,本文基于汉宁窗函数的特点,提出了一种可调节参数的窗函数。通过仿真实验,给投影数据加入噪声,采取不同的参数进行图像重建,考察不同的参数对噪声的抑制作用。实际检测时,应根据具体要求选择合理的参数进行重建。

In the CT image reconstruction, Filtered Backprojection （FBP） algorithm is widely used recently, in which filter design is an important part and critical step When the filter is designed, the main point is how to select the window function. Based on the characteristics of Hanning, a kind of window function with adjustable parameters is put forward. The simulation experiments are completed in which and the projection data are mixed with noise and then the images are reconstructed with different parameters. The simulation results show that different parameters have different inhibitory effects on noise. So reasonable parameters are need to select to reconstruct images according to the special requirements in practical applications.