title: Phase-encoded binary filters for optical pattern recognition.
abstract: We have previously reported a technique for suppressing one of the two first-order diffracted beams from binary phase-only gratings written onto spatial light modulators by writing the cosine and sine filters onto separate halves of a spatial light modulator. We report the use of this phase-encoding technique for constructing binary approximations to continuous phase-only filters for use in optical correlators. Computer simulations of these filters are given. These results show that our new filters do not recognize inverted occurrences of the input object in contrast to binary phase-only filters made using previous techniques. In addition, these filters yield a greatly improved SNR over earlier types of filters.
authors.forename: J A
authors.initials: JA
authors.lastname: Davis
authors.forename: D M
authors.initials: DM
authors.lastname: Cottrell
authors.forename: G W
authors.initials: GW
authors.lastname: Bach
authors.forename: R A
authors.initials: RA
authors.lastname: Lilly