A partially coherent imaging system distorts images nonlinearly. We investigate the restoration of such images by use of a second-degree nonlinear filter which is optimum for low-contrast images. The performance of this filter is shown to be better than that of a linear inverse filter, especially as the imaging becomes more coherent.
© 1981 Applied Optics
Bahaa E. A. Saleh and Soheil I. Sayegh, "Restoration of partially coherent images by use of a second-degree nonlinear filter," Appl. Opt. 20, 4089-4093 (1981)