title: Quad-phase correlation filters for pattern recognition.
abstract: A quad-phase-only filter (QPOF) is introduced. It is shown that the QPOF can have improved correlation response and signal-to-noise ratio with respect to the Hartley binary phase-only filter for some objects.
authors.forename: F M
authors.initials: FM
authors.lastname: Dickey
authors.forename: B D
authors.initials: BD
authors.lastname: Hansche