Backprojection inverse filtration for laminographic reconstruction
Backprojection inverse filtration for laminographic reconstruction
复制标题
用于分层重建的反投影逆过滤
DOI：
10.1049/iet-ipr.2017.1344
复制
发表时间：
2018
影响因子：
2.3
通讯作者：
Blumensath T
中科院分区：
文献类型：
--
作者：
Blumensath T
传统的断层扫描使用圆形轨迹，在这里，滤波反投影通常工作得很好。然而，对于具有大纵横比的对象，旋转层析成像通常是不可行的。在这些情况下，其他轨迹可能更合适。对于一般轨迹，滤波反投影方法可能无法很好地工作，并且完全迭代重建可能需要计算。因此，在这项研究中，作者提出了第三种范式，结合了这两种技术的各个方面。他们使用插值和反投影技术，使用在不同方向拍摄的投影图像来生成物体内部结构的初始估计。根据用于计算断层摄影投影的扫描几何结构，该初始估计可以被理解为实际结构的模糊（滤波）近似。对于每个扫描几何结构，他们指定等效的模糊算子，该算子将直接从对象的内部结构的表示提供相同的估计。然后，他们使用迭代技术来反转这种滤波操作，从而从其模糊表示的估计中估计内部结构。
Traditional tomography uses circular trajectories and here, filtered backprojection often works well. However, for objects with large aspect ratios, rotational tomography is often not feasible. In these cases, other trajectories can be more appropriate. For generic trajectories, filtered backprojection methods might not work well and full iterative reconstruction can be computationally demanding. In this study, the authors thus propose a third paradigm that combines aspects of both of these techniques. They use interpolation and backprojection techniques to generate an initial estimate of an object's internal structure using projection images taken at different orientations. Depending on the scanning geometry used to calculate the tomographic projections, this initial estimate can be understood as a blurred (filtered) approximation of the actual structure. For each scanning geometry, they specify the equivalent blurring operator that would provide the same estimate directly from a representation of the object's internal structure. They then use iterative techniques to invert this filtering operation, thus estimating the internal structure from the estimate of its blurred representation.