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.
© 1989 Optical Society of America
Fred M. Dickey and Bruce D. Hansche, "Quad-phase correlation filters for pattern recognition," Appl. Opt. 28, 1611-1613 (1989)