  X-ray ptychography is one of the versatile techniques for nanometer
resolution imaging. The magnitude of the diffraction patterns is recorded on a
detector and the phase of the diffraction patterns is estimated using phase
retrieval techniques. Most phase retrieval algorithms make the solution
well-posed by relying on the constraints imposed by the overlapping region
between neighboring diffraction pattern samples. As the overlap between
neighboring diffraction patterns reduces, the problem becomes ill-posed and the
object cannot be recovered. To avoid the ill-posedness, we investigate the
effect of regularizing the phase retrieval algorithm with image priors for
various overlap ratios between the neighboring diffraction patterns. We show
that the object can be faithfully reconstructed at low overlap ratios by
regularizing the phase retrieval algorithm with image priors such as
Total-Variation and Structure Tensor Prior. We also show the effectiveness of
our proposed algorithm on real data acquired from an IC chip with a coherent
X-ray beam.
