1. A system for improving the quality of an imaging system image, comprising: an input/output interface configured to receive the imaging system image; a processor in communication with the input/output interface, the processor being configured to: a) subdivide the imaging system image; b) apply discrete cosine transform (DCT) denoising using a hard thresholding rule; c) apply an iterative expectation-maximisation (EM) regression model; d) estimate the point spread function; e) set the DCT deconvolution factor to the estimated point spread function; f) apply the DCT deconvolution factor to the subdivided image; and g) provide a restored image based on the deconvoluted subdivided image.