| This study investigates methods to achieve efficient restoration of digital images degraded by uncorrected geometric aberrations in imaging optical systems. Two areas of investigation are (1) efficient use of current and classical restoration methods for post-detection aberration correction, and (2) compression coding of aberrated point-spread-functions for use in those methods to minimize computer storage resource requirements.; In the first area, the use of classical frequency-domain methods is explored for restoring images blurred with space-variant point-spread-functions. Space-variant images with physical optics blurs are simulated and restored with a new method combining classical Wiener filtering and sectioning with an additional technique to accommodate the specific space-variant characteristics of physical optical systems composed of spherical surfaces. In the second area, a new adaptively fit, low-order analytical model for aberrated PSFs is developed.; In the first area, it is found that a modified approach to classical Wiener filtering may be effectively applied to small sub-images at large field angle where the point-spread-function Strehl ratio has diminished to as little as 5%. It is necessary, however, to compensate for the spatial spread and shift of physical optics PSFs in the application frame in order to avoid excessive computation or overwhelming edge effects. In the second area, compression of more than two orders of magnitude is achieved with the new analytical PSF model. |
