A simple coherent-imaging method due to Paganin et al. is widely employed for phase-amplitude reconstruction of samples using a single paraxial x-ray propagation-based phase-contrast image. The method assumes that the sample-to-detector distance is sufficiently small for the associated Fresnel number to be large compared to unity. The algorithm is particularly effective when employed in a tomographic setting, using a single propagation-based phase-contrast image for each projection. Here we develop a simple extension of the method, which improves the reconstructed contrast of very fine sample features. This provides first-principles motivation for boosting fine spatial detail associated with high Fourier frequencies, relative to the original method, and was inspired by several recent works employing empirically-obtained Fourier filters to a similar end.

中文翻译：

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通过将周期性边界条件纳入单距离硬 X 射线相位检索来提高空间分辨率

Paganin 等人提出的一种简单的相干成像方法。被广泛用于使用单个基于近轴 X 射线传播的相衬图像对样本进行相位幅度重建。该方法假设样本到检测器的距离足够小，以便相关的菲涅耳数与 1 相比较大。当在断层摄影设置中使用时，该算法特别有效，为每个投影使用单个基于传播的相位对比图像。在这里，我们开发了该方法的简单扩展，它提高了非常精细的样本特征的重建对比度。相对于原始方法，这提供了提升与高傅立叶频率相关的精细空间细节的第一性原理动机，