Restoration of color images degraded by chromatic aberrations

A mathematical study of spatial degradations which modify the color in images is presented, and digital methods of image restoration to compensate for these effects have been investigated. Color images are often degraded by the residual chromatic aberrations of the optical system, causing chromatism errors and a decrease of resolution. Images and the line spread function of a single lens system with longitudinal chromatic aberrations are scanned through color filters, and the optical transfer functions for the tristimulus values are obtained. Standard and modified inverse, Wiener, and geometrical mean filters are applied in various combinations to the tristimulus values for focus in different system planes. Geometrical mean filters applied separately to the tristimulus components seem to give the best overall restoration of edge response.