The APEX method is a noniterative direct blind deconvolution technique that can sharpen certain kinds of high-resolution images in quasi real time. The method is predicated on a restricted class of blurs, in the form of 2-D radially symmetric, bell-shaped, heavy-tailed, probability density functions. Not all images can be usefully enhanced with the APEX method. However, the method is found effective on a broad class of galaxy images, including Hubble space telescope advanced camera for surveys (ACS) color imagery. APEX-detected optical transfer functions that successfully sharpen these images are very far from Gaussian, and of a type seldom found in the imaging literature. Several examples are given where significantly sharper and visually striking reconstructions are obtained, with sharpening confirmed by the tripling or quadrupling of image gradient norms.
Alfred S. Carasso,
"APEX blind deconvolution of color Hubble space telescope imagery and other astronomical data," Optical Engineering 45(10), 107004 (1 October 2006). https://doi.org/10.1117/1.2362579