Application of ImPASS to translated images produces image resolution below the optical diffraction resolution limit

Abstract

The image resolution produced by a lens/camera system is limited by the digital sampling frequency of the sensor and the diffraction limit as imposed by the front aperture diameter of the optics. A previous study using Image Phase Alignment Super-Sampling (ImPASS) demonstrated that Fourier phase information from a sequence of slightly displaced images can be used to achieve image resolution beyond the digital sampling frequency. In continuation of that work, this study applies ImPASS to sequences of slightly displaced empirical images for a range of aperture settings. The frames are up-sampled, aligned, and combined into a single frame. Application of Self-Deconvolving Data Restoration Algorithm (SeDDaRA) deconvolution reveals features with higher resolution. The slanted edge technique is applied to the processed images to establish the angular resolution of the system as a function of the effective f-number. When compared to Abbe’s resolution criteria, the measurements reveal that this super-sampling method produces image resolution that subceeds the diffraction limit of the lens/camera system.