A Stitching Algorithm for High-order Spatial Frequencies in Diffraction Pattern Data

Coherent diffractive imaging is not limited by the classic Rayleigh criterion that restricts resolution in conventional microscopy. In CDI, resolution is limited only by the spatial frequencies of data collected in an image. However, higher spatial frequencies occur at larger distances from the central bright spot, where low signal-to-noise ratios make data collection more difficult. As such, we have developed a technique in which a lens is mounted to a movable translation stage holding a beam profiler. This lens is used to magnify weak signals at the edges of diffraction patterns but induces a shift between distances in the object plane and the detector plane. As a result, images collected at varying positions will overlap and include redundant image data. We will present a numerical technique used to identify this scaling fraction between the two planes and stich multiple overlapping images to create a single composite diffraction pattern for enhanced reconstruction resolution. Results will be provided for an Air Force target card and adherent mammalian cancer cells used as imaging samples.