Image restoration is concerned with filtering the digital image to minimize the effect of degradations. Degradation is produced by the sensing environment during image acquisition by optical or electronic devices. The effectiveness of image filtering depends on the extent and the accuracy of the knowledge of the degradation process as well as on the filter design.
In OpenCV, there are several isotropic and anisotropic filters available operating on both spatial and frequency domains. One of the most recent filters is the retina filter, which is based on a model of the human visual system. There is a class named Retina to perform spatio-temporal filtering modeling the two main retina information channels, which are parvocellular (parvo) due to foveal vision and magnocellular (magno) due to peripheral vision. The parvo channel is related to detail extraction while the magno channel is dedicated to motion analysis.