带阈值滤波的迭代法三维ECT图像重建

3D ECT image reconstruction by iterative method with threshold filtering

针对Landweber迭代法用于三维ECT重建时,需要的迭代次数多且重建图像中含有大量伪迹的问题,提出了一种带阈值滤波的迭代重建法.该方法利用Landweber迭代法重建一初始图像,用阈值滤波获得改进图像,为了获得最佳阈值,依次用有限个离散化阈值对初始图像做二值化处理,计算出二值化图像对应的电容估计值与电容测量值之间的误差,并将对应最小误差的阈值确定为最佳阈值.仿真实验结果表明,自适应阈值滤波能够显著减少重建图像中的伪迹和重建时间,该方法具有良好的应用潜力.

To solve the problem of requiring many times of iterations and containing a lot of artifacts in the reconstructed images when the Landweber iteration algorithm is used for 3D ECT reconstruction,an iterative reconstruction method with threshold filtering was proposed. An initial image was reconstructed with the Landweber iteration algorithm,and an improved image was obtained by means of threshold filtering. In order to obtain an optimum threshold,the initial image was successively binarized with a limited amount of discretized thresholds. In addition, the errors between the corresponding estimated and measured capacitances of binarized image were calculated,and the threshold with the minimum error was chosen as the optimum threshold. The simulated results showthat the adaptive threshold filtering can obviously reduce the reconstruction time and artifacts in the reconstructed images. As a result,the proposed method has a good application potential.