PCPS 方法用扩散先验降低 X-ray 叠层成像扫描重叠需求
Progressive Coupling Method for Diffusion Posterior Sampling in Ptychography
一篇成像方向论文：用扩散先验做后验采样，让叠层成像在低重叠扫描下也能重建准，做 X-ray 成像的可以看看。
叠层成像（Ptychography）依赖重叠衍射测量提供的冗余信息来重建样品，但密集扫描会增加采集时间与数据量。论文提出渐进耦合后验采样方法 PCPS，在高不确定性阶段扩大解空间探索，随重建细化逐步加强扩散引导一致性。在真实 X-ray 叠层数据、多种扫描重叠率下的实验显示，PCPS 的重建精度持续优于传统迭代方法和现有扩散后验采样器，低重叠时优势更明显。结果表明扩散先验可以降低精确重建所需的测量冗余。
Progressive Coupling Method for Diffusion Posterior Sampling in Ptychography
Ptychography is a computational imaging method that reconstructs a sample from overlapping diffraction measurements. This technique relies on these overlapping measurements to provide the redundancy information needed for robust reconstruction, but dense scanning increases acquisition time and data volume. Reducing scan overlaps can improve measurement efficiency but weakens the physical constraints available for reconstruction. Diffusion models provide strong learned prior information, offering a promising approach to compensate for the loss of measurement redundancy. However, effectively utilizing this prior information under weak measurement constraints remains a challenge. We propose a progressive coupling posterior sampling (PCPS) method, which allows for a broader exploration of the solution space under high uncertainty while maintaining stronger diffusion-guided consistency as the reconstruction becomes more refined. Experiments on real X-ray ptychographic data at various scan overlaps demonstrate that PCPS consistently improves reconstruction accuracy compared to traditional iterative methods and existing diffusion posterior samplers, especially at low overlaps. These results show that diffusion priors can reduce the measurement redundancy required for accurate ptychography reconstruction.
