title: Complex spatial filtering with binary masks.
abstract: Usually a hologram is produced by means of an interference experiment. Here, however, we let a computer- guided plotter draw the hologram. The plot, which has to be minified and recorded on film, contains no grey, only binary transmittance values. Our binary holograms yield reconstructed images of a quality equal to that of images obtained from usual holograms of comparable dimensions. When a Fourier hologram is inserted into the Fraunhofer plane of a coherent image forming system, it acts as a special type of a spatial filter, a so-called optical matched filter. Our binary matched filter is suitable for optical character recognition, the same as the usual optical matched filter introduced by Vander Lugt.
authors.affiliation: The IBM Corporation, ResearchDivision, San Jose, California 95114, USA.
authors.forename: B R
authors.initials: BR
authors.lastname: Brown
authors.forename: A W
authors.initials: AW
authors.lastname: Lohmann