Faragó Tomáš, Spiecker Rebecca, Hurst Mathias, Zuber Marcus, Cecilia Angelica, Baumbach Tilo
Opt Lett. 2024 Sep 15;49(18):5159-5162. doi: 10.1364/OL.530330.
We derive a phase retrieval formula for propagation-based phase contrast X-ray imaging that does not require weakly attenuating objects or short propagation distances. It is directly applicable to both single- and multiple-distance scenarios. We show the validity conditions and study the error of the underlying mutual intensity approximation, which uses the common assumptions of weak phase shift variations and phase-attenuation duality. The approximation generalizes those behind the transport of intensity (TIE) and contrast transfer function (CTF) models, and it approaches them when their respective additional assumptions are satisfied. When they are not, it clearly outperforms them, which we show both theoretically and practically on synthetic and measured data.
我们推导了一种基于传播的相衬X射线成像的相位恢复公式，该公式不需要弱衰减物体或短传播距离。它直接适用于单距离和多距离场景。我们展示了有效性条件，并研究了潜在互强度近似的误差，该近似使用了弱相移变化和相衰减对偶性的常见假设。该近似推广了强度传输（TIE）和对比度传递函数（CTF）模型背后的近似，并且在满足它们各自的附加假设时接近它们。当不满足这些假设时，它明显优于它们，我们在合成数据和实测数据上从理论和实践两方面都证明了这一点。
