论文标题

稳健的相位检索,并具有复杂性指导,用于连贯的X射线成像

Robust phase retrieval with complexity-guidance for coherent X-ray imaging

论文作者

Butola, Mansi, Rajora, Sunaina, Khare, Kedar

论文摘要

从连贯的X射线成像(CXI)实验中记录的噪声不完整的傅立叶强度数据(CXI)实验中稳定且可靠的解决方案的重建是一个具有挑战性的问题。以大量误差(ER)迭代结束的轻松平均交替反射(RAAR)算法是一个流行的选择。从独立的随机猜测开始,通常使用了数百次RAAR-ER算法来获得试验解决方案,然后将其平均以获得相检索转移函数(PRTF)。在本文中,我们从我们在最近的作品中引入的复杂性参数的角度研究了使用RAAR-ER方法学获得的相位检索解决方案。我们观察到,与基于复杂性参数的预期相比,单一的RAAR-ER算法产生的解决方案具有更高的复杂性,这是溶液中杂散的高频高频粒状伪像,即使在平均进行了许多试验解决方案之后,似乎也不会完全消失。然后,我们描述了一种CG-RAAR(复杂性指导RAAR)相位检索方法,该方法可以有效地解决此不一致问题并提供无伪影的解决方案。首先用模拟的未阻止的噪声傅立叶强度数据来说明CG-RAAR方法,然后应用于CXIDB数据库可用的中心块嘈杂的蓝细菌数据。我们使用CG-RAAR的模拟和实验结果表明,对流行的RAAR-ER算法进行了两个重要的改进。平均过程后的CG-RAAR解决方案更可靠,因为它包含与PRTF曲线估计的分辨率一致的最小特征。其次,由于CG-RAAR溶液的单个运行没有粒状伪像,因此平均过程所需的试验解决方案数量减少。

Reconstruction of a stable and reliable solution from noisy incomplete Fourier intensity data recorded in a coherent X-ray imaging (CXI) experiment is a challenging problem. The Relaxed Averaged Alternating Reflections (RAAR) algorithm that is concluded with a number of Error Reduction (ER) iterations is a popular choice. The RAAR-ER algorithm is usually employed for several hundreds of times starting with independent random guesses to obtain trial solutions that are then averaged to obtain the phase retrieval transfer function (PRTF). In this paper, we examine the phase retrieval solution obtained using the RAAR-ER methodology from perspective of the complexity parameter that was introduced by us in recent works. We observe that a single run of the RAAR-ER algorithm produces a solution with higher complexity compared to what is expected based on the complexity parameter as manifested by spurious high frequency grainy artifacts in the solution that do not seem to go away completely even after a number of trial solutions are averaged. We then describe a CG-RAAR (Complexity Guided RAAR) phase retrieval method that can effectively address this inconsistency problem and provides artifact-free solutions. The CG-RAAR methodology is first illustrated with simulated unblocked noisy Fourier intensity data and later applied to centrally-blocked noisy cyanobacterium data which is available from the CXIDB database. Our simulation and experimental results using CG-RAAR suggest two important improvements over the popular RAAR-ER algorithm. The CG-RAAR solutions after the averaging procedure is more reliable in the sense that it contains smallest features consistent with the resolution estimated by the PRTF curve. Secondly, since the single run of the CG-RAAR solution does not have grainy artifacts, the number of trial solutions needed for the averaging process is reduced.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源