Ptychography, a special case of the phase retrieval problem, is a popular method in modern imaging. Its measurements are based on the shifts of a locally supported window function. In general, direct recovery of an object from such measurements is known to be an ill-posed problem. Although for some windows the conditioning can be controlled, for a number of important cases it is not possible, for instance for Gaussian windows. In this paper we develop a subspace completion algorithm, which enables stable reconstruction for a much wider choice of windows, including Gaussian windows. The combination with a regularization technique leads to improved conditioning and better noise robustness.

Ptychography 是相位检索问题的一个特例，是现代成像中的一种流行方法。它的测量基于本地支持的窗函数的偏移。通常，已知从此类测量中直接恢复对象是不适定问题。尽管对于某些窗口可以控制调节，但对于许多重要情况，这是不可能的，例如对于高斯窗口。在本文中，我们开发了一种子空间完成算法，该算法可以为更广泛的窗口选择（包括高斯窗口）实现稳定重建。与正则化技术的结合导致改进的调节和更好的噪声鲁棒性。