title: Linear versus logarithmic spatial filtering in the removal of multiplicative noises.
abstract: Linear and logarithmic coherent spatial-filtering techniques are compared in the separation of multiplicative noise from an image in a coherent-optical image-processing system. It is demonstrated that both techniques are effective in the removal of simple grating-type high-frequency noises, but that linear filtering cannot remove noise of spatial frequencies lower than 5 lines/cm, whereas logarithmic filtering can.
authors.affiliation: Department of Electrical Engineering, The University of Alabama, PO Box 6169, University, Alabama 35486, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Karim
authors.forename: H K
authors.initials: HK
authors.lastname: Liu